National Library of Energy BETA

Sample records for int cosmic ray

  1. Cosmic ray recipes

    E-Print Network [OSTI]

    Franco Ferrari; Ewa Szuszkiewicz

    2006-01-08

    Cosmic rays represent one of the most fascinating research themes in modern astronomy and physics. After almost a century since their discovery, a huge amount of scientific literature has been written on this topic and it is not always easy to extract from it the necessary information for somebody who approaches the subject for the first time. This has been the main motivation for preparing this article, which is a concise and self-contained review for whoever is interested in studying cosmic rays. The priority has been given here to well established facts, which are not at risk to get obsolete in a few years due to the fast progress of the research in this field. Also many data are presented, which are useful to characterize the doses of ionizing radiation delivered to organisms living on the Earth due to cosmic rays. The technical terms which are often encountered in the scientific literature are explained in a separate appendix.

  2. Galactic cosmic rays and nucleosynthesis

    SciTech Connect (OSTI)

    Kiener, Juergen [CSNSM, CNRS-IN2P3 and Universite Paris-Sud, Bat. 104-108, 91405 Orsay Campus (France)

    2010-03-01

    The nucleosynthesis of the light elements Li, Be and B by galactic cosmic rays is presented. Observations of cosmic rays and the nuclear reactions responsible for Li, Be and B nucleosynthesis are described, followed by some words on propagation. At the end, some open questions concerning galactic cosmic rays are discussed.

  3. The Origin of Cosmic Rays

    ScienceCinema (OSTI)

    Blasi, Pasquale [INAF/Arcetri-Italy and Fermilab, Italy

    2010-01-08

    Cosmic Rays reach the Earth from space with energies of up to more than 1020 eV, carrying information on the most powerful particle accelerators that Nature has been able to assemble. Understanding where and how cosmic rays originate has required almost one century of investigations, and, although the last word is not written yet, recent observations and theory seem now to fit together to provide us with a global picture of the origin of cosmic rays of unprecedented clarity. Here we will describe what we learned from recent observations of astrophysical sources (such as supernova remnants and active galaxies) and we will illustrate what these observations tell us about the physics of particle acceleration and transport. We will also discuss the ?end? of the Galactic cosmic ray spectrum, which bridges out attention towards the so called ultra high energy cosmic rays (UHECRs). At ~1020 eV the gyration scale of cosmic rays in cosmic magnetic fields becomes large enough to allow us to point back to their sources, thereby allowing us to perform ?cosmic ray astronomy?, as confirmed by the recent results obtained with the Pierre Auger Observatory. We will discuss the implications of these observations for the understanding of UHECRs, as well as some questions which will likely remain unanswered and will be the target of the next generation of cosmic ray experiments.

  4. Ultrahigh Energy Cosmic Rays Detection

    E-Print Network [OSTI]

    Carla Aramo

    2005-09-06

    The paper describes methods used for the detection of cosmic rays with energies above 10^18 eV (UHECR, UltraHigh Energy Cosmic Rays). It had been anticipated there would be a cutoff in the energy spectrum of primary cosmic rays around 3 10^19 eV induced by their interaction with the 2.7 K primordial photons. This has become known as the GZK cutoff. However, several showers have been detected with estimated primary energy exceeding this limit.

  5. Cosmic Rays and Global Warming

    E-Print Network [OSTI]

    T. Sloan; A W Wolfendale

    2007-06-28

    It has been claimed by others that observed temporal correlations of terrestrial cloud cover with `the cosmic ray intensity' are causal. The possibility arises, therefore, of a connection between cosmic rays and Global Warming. If true, the implications would be very great. We have examined this claim to look for evidence to corroborate it. So far we have not found any and so our tentative conclusions are to doubt it. Such correlations as appear are more likely to be due to the small variations in solar irradiance, which, of course, correlate with cosmic rays. We estimate that less than 15% of the 11-year cycle warming variations are due to cosmic rays and less than 2% of the warming over the last 35 years is due to this cause.

  6. Cosmic Rays and Global Warming

    E-Print Network [OSTI]

    Sloan, T

    2007-01-01

    It has been claimed by others that observed temporal correlations of terrestrial cloud cover with `the cosmic ray intensity' are causal. The possibility arises, therefore, of a connection between cosmic rays and Global Warming. If true, the implications would be very great. We have examined this claim to look for evidence to corroborate it. So far we have not found any and so our tentative conclusions are to doubt it. Such correlations as appear are more likely to be due to the small variations in solar irradiance, which, of course, correlate with cosmic rays. We estimate that less than 15% of the 11-year cycle warming variations are due to cosmic rays and less than 2% of the warming over the last 35 years is due to this cause.

  7. Cosmic Rays at the Knee

    E-Print Network [OSTI]

    Thomas K. Gaisser

    2006-08-25

    Several kinds of measurements are combined in an attempt to obtain a consistent estimate of the spectrum and composition of the primary cosmic radiation through the knee region. Assuming that the knee is a signal of the high-energy end of a galactic cosmic-ray population, I discuss possible signatures of a transition to an extra-galactic population and how they might be detected.

  8. Cosmic Rays and Global Warming

    SciTech Connect (OSTI)

    Sloan, T.; Wolfendale, A. W.

    2008-01-24

    Some workers have claimed that the observed temporal correlations of (low level) terrestrial cloud cover with the cosmic ray intensity changes, due to solar modulation, are causal. The possibility arises, therefore, of a connection between cosmic rays and Global Warming. If true, the implications would be very great. We have examined this claim in some detail. So far, we have not found any evidence in support and so our conclusions are to doubt it. From the absence of corroborative evidence we estimate that less than 15% at the 95% confidence level, of the 11-year cycle warming variations are due to cosmic rays and less than 2% of the warming over the last 43 years is due to this cause. The origin of the correlation itself is probably the cycle of solar irradiance although there is, as yet, no certainty.

  9. Cosmic rays & Neutrinos Historical development

    E-Print Network [OSTI]

    Gaisser, Thomas K.

    Cosmic rays & Neutrinos Historical development Mumbai, 14/12/12 Tom Gaisser 1 #12; Inven@on of neutrinos, 1930 Mumbai, 14/12/12 Tom Gaisser 2 ETH@) : 1956 Mumbai, 14/12/12 Tom Gaisser 3 25 years from inven@on to experimental

  10. High-energy Cosmic Rays

    E-Print Network [OSTI]

    Thomas K. Gaisser; Todor Stanev

    2005-10-11

    After a brief review of galactic cosmic rays in the GeV to TeV energy range, we describe some current problems of interest for particles of very high energy. Particularly interesting are two features of the spectrum, the `knee' above $10^{15}$ eV and the `ankle' above $10^{18}$ eV. An important question is whether the highest energy particles are of extra-galactic origin and, if so, at what energy the transition occurs. A theme common to all energy ranges is use of nuclear abundances as a tool for understanding the origin of the cosmic radiation.

  11. Characterising CCDs with cosmic rays

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Fisher-Levine, M.; Nomerotski, A.

    2015-08-06

    The properties of cosmic ray muons make them a useful probe for measuring the properties of thick, fully depleted CCD sensors. The known energy deposition per unit length allows measurement of the gain of the sensor's amplifiers, whilst the straightness of the tracks allows for a crude assessment of the static lateral electric fields at the sensor's edges. The small volume in which the muons deposit their energy allows measurement of the contribution to the PSF from the diffusion of charge as it drifts across the sensor. In this work we present a validation of the cosmic ray gain measurementmore »technique by comparing with radioisotope gain measurments, and calculate the charge diffusion coefficient for prototype LSST sensors.« less

  12. High-energy cosmic ray interactions

    SciTech Connect (OSTI)

    Engel, Ralph; Orellana, Mariana; Reynoso, Matias M.; Vila, Gabriela S.

    2009-04-30

    Research into hadronic interactions and high-energy cosmic rays are closely related. On one hand--due to the indirect observation of cosmic rays through air showers--the understanding of hadronic multiparticle production is needed for deriving the flux and composition of cosmic rays at high energy. On the other hand the highest energy particles from the universe allow us to study the characteristics of hadronic interactions at energies far beyond the reach of terrestrial accelerators. This is the summary of three introductory lectures on our current understanding of hadronic interactions of cosmic rays.

  13. Terrestrial Effects of High Energy Cosmic Rays

    E-Print Network [OSTI]

    Atri, Dimitra

    2011-04-26

    On geological timescales, the Earth is likely to be exposed to higher than the usual flux of high energy cosmic rays (HECRs) from astrophysical sources such as nearby supernovae, gamma ray bursts or by galactic shocks. ...

  14. 30TH INTERNATIONAL COSMIC RAY CONFERENCE Radio Detection of UltraHigh Energy Cosmic Rays

    E-Print Network [OSTI]

    Falcke, Heino

    offers a number of interesting advantages. Since radio waves suffer no attenuation, radio measurements30TH INTERNATIONAL COSMIC RAY CONFERENCE Radio Detection of Ultra­High Energy Cosmic Rays HEINO: The radio technique for the detection of cosmic particles has seen a major revival in recent years. New

  15. High-energy cosmic-ray acceleration

    E-Print Network [OSTI]

    Bustamante, M; de Paula, W; Duarte Chavez, J A; Gago, A M; Hakobyan, H; Jez, P; Monroy Montańez, J A; Ortiz Velasquez, A; Padilla Cabal, F; Pino Rozas, M; Rodriguez Patarroyo, D J; Romeo, G L; Saldańa-Salazar , U J; Velasquez, M; von Steinkirch, M

    2010-01-01

    We briefly review the basics of ultrahigh-energy cosmic-ray acceleration. The Hillas criterion is introduced as a geometrical criterion that must be fulfilled by potential acceleration sites, and energy losses are taken into account in order to obtain a more realistic scenario. The different available acceleration mechanisms are presented, with special emphasis on Fermi shock acceleration and its prediction of a power-law cosmic-ray energy spectrum. We conclude that first-order Fermi acceleration, though not entirely satisfactory, is the most promising mechanism for explaining the ultra-high-energy cosmic-ray flux.

  16. 28th International Cosmic Ray Conference 2237 Transition Radiation Detectors for Cosmic Rays Near the

    E-Print Network [OSTI]

    Hörandel, Jörg R.

    28th International Cosmic Ray Conference 2237 Transition Radiation Detectors for Cosmic Rays Near detector areas of several square meters. X-ray transition radiation detectors (TRDs) appear to provide of the TRD does not satu- rate for Lorentz factors less than 105 . We have designed detectors to meet

  17. Cosmic ray penetration in diffuse clouds

    E-Print Network [OSTI]

    Morlino, G; Krause, J

    2015-01-01

    Cosmic rays are a fundamental source of ionization for molecular and diffuse clouds, influencing their chemical, thermal, and dynamical evolution. The amount of cosmic rays inside a cloud also determines the $\\gamma$-ray flux produced by hadronic collisions between cosmic rays and cloud material. We study the spectrum of cosmic rays inside and outside of a diffuse cloud, by solving the stationary transport equation for cosmic rays including diffusion, advection and energy losses due to ionization of neutral hydrogen atoms. We found that the cosmic ray spectrum inside a diffuse cloud differs from the one in the interstellar medium (ISM) for energies smaller than $E_{br}\\approx 100$ MeV, irrespective of the model details. Below $E_{br}$, the spectrum is harder (softer) than that in the ISM if the latter is a power law $\\propto p^{-s}$ with $s$ larger (smaller) than $\\sim0.42$. As a consequence also the ionization rate due to CRs is strongly affected. Assuming an average Galactic spectrum similar to the one infe...

  18. Detecting cosmic rays of the highest energies

    E-Print Network [OSTI]

    F. Vannucci

    2001-06-06

    Charged cosmic rays have been measured up to macroscopic energies. Concerning neutrinos, the detection is still limited to terrestrial ones (apart from supernova production). A new way to search for extragalactic neutrinos is discussed.

  19. ETTORE MAJORANA FOUNDATION AND CENTRE FOR SCIENTIFIC CULTURE INTERNATIONAL SCHOOL OF COSMIC-RAY ASTROPHYSICS

    E-Print Network [OSTI]

    Hörandel, Jörg R.

    PropagationofCosmicRays-1986CosmicGammaRaysandCosmicRadiation-1988CosmicRays, Supernovae,andtheInterstellarMedium-1990Particle

  20. ETTORE MAJORANA FOUNDATION AND CENTRE FOR SCIENTIFIC CULTURE INTERNATIONAL SCHOOL OF COSMIC-RAY ASTROPHYSICS

    E-Print Network [OSTI]

    Hörandel, Jörg R.

    RadiationinContemporaryAstrophysics-1984GenesisandPropagationofCosmicRays-1986CosmicGammaRaysandCosmicRadiation-1988CosmicRays, Supernovae,andtheInterstellarMedium

  1. Gamma Ray Bursts from Ordinary Cosmic Strings

    E-Print Network [OSTI]

    R. H. Brandenberger; A. T. Sornborger; M. Trodden

    1993-02-12

    We give an upper estimate for the number of gamma ray bursts from ordinary (non-superconducting) cosmic strings expected to be observed at terrestrial detectors. Assuming that cusp annihilation is the mechanism responsible for the bursts we consider strings arising at a GUT phase transition and compare our estimate with the recent BATSE results. Further we give a lower limit for the effective area of future detectors designed to detect the cosmic string induced flux of gamma ray bursts.

  2. The HAWC Gamma-Ray Observatory: Observations of Cosmic Rays

    E-Print Network [OSTI]

    Abeysekara, A U; Alvarez, C; Álvarez, J D; Arceo, R; Arteaga-Velázquez, J C; Solares, H A Ayala; Barber, A S; Baughman, B M; Bautista-Elivar, N; Belmont, E; BenZvi, S Y; Berley, D; Rosales, M Bonilla; Braun, J; Caballero-Lopez, R A; Caballero-Mora, K S; Carramińana, A; Castillo, M; Cotti, U; Cotzomi, J; de la Fuente, E; De León, C; DeYoung, T; Hernandez, R Diaz; Díaz-Vélez, J C; Dingus, B L; DuVernois, M A; Ellsworth, R W; Fernandez, A; Fiorino, D W; Fraija, N; Galindo, A; Garfias, F; González, L X; González, M M; Goodman, J A; Grabski, V; Gussert, M; Hampel-Arias, Z; Hui, C M; Hüntemeyer, P; Imran, A; Iriarte, A; Karn, P; Kieda, D; Kunde, G J; Lara, A; Lauer, R J; Lee, W H; Lennarz, D; Vargas, H León; Linares, E C; Linnemann, J T; Longo, M; Luna-GarcIa, R; Marinelli, A; Martinez, H; Martinez, O; Martínez-Castro, J; Matthews, J A J; Miranda-Romagnoli, P; Moreno, E; Mostafá, M; Nava, J; Nellen, L; Newbold, M; Noriega-Papaqui, R; Oceguera-Becerra, T; Patricelli, B; Pelayo, R; Pérez-Pérez, E G; Pretz, J; Rivičre, C; Rosa-González, D; Salazar, H; Salesa, F; Sanchez, F E; Sandoval, A; Santos, E; Schneider, M; Silich, S; Sinnis, G; Smith, A J; Sparks, K; Springer, R W; Taboada, I; Toale, P A; Tollefson, K; Torres, I; Ukwatta, T N; Villaseńor, L; Weisgarber, T; Westerhoff, S; Wisher, I G; Wood, J; Yodh, G B; Younk, P W; Zaborov, D; Zepeda, A; Zhou, H

    2013-01-01

    We describe measurements of GeV and TeV cosmic rays with the High-Altitude Water Cherenkov Gamma-Ray Observatory, or HAWC. The measurements include the observation of the shadow of the moon; the observation of small-scale and large-scale angular clustering of the TeV cosmic rays; the prospects for measurement of transient solar events with HAWC; and the observation of Forbush decreases with the HAWC engineering array and HAWC-30.

  3. 28th International Cosmic Ray Conference 4041 Long-Term Cosmic Ray Intensities: Physical Reconstruc-

    E-Print Network [OSTI]

    Usoskin, Ilya G.

    model of the heliosphere, we calculate the expected differential spectra and integral intensity of galactic cosmic rays at the Earth's orbit since 1610. The calculated cosmic ray integral intensity. (2000) have recently calculated the open solar magnetic flux for the last 400 years from sunspot data

  4. Giant AGN Flares and Cosmic Ray Bursts

    E-Print Network [OSTI]

    Glennys R. Farrar; Andrei Gruzinov

    2008-09-15

    We predict a new class of very intense, short-duration AGN flares capable of accelerating the highest energy cosmic rays, resulting from the tidal disruption of a star or from a disk instability. The rate and power of these flares readily explains the observed flux and density statistics of UHECRs. The photon bursts produced by the predicted AGN flares are discussed; they may soon be detectable. Observations are shown to exclude that continuous jets of powerful Active Galactic Nuclei are the sole source of ultrahigh energy cosmic rays; the stringent requirements for Gamma Ray Bursts to be the source are delineated.

  5. Dark Matter Signals In Cosmic Rays?

    E-Print Network [OSTI]

    Shlomo Dado; Arnon Dar

    2009-03-10

    The flux of the diffuse gamma-ray background radiation (GBR) does not confirm that the excess in the flux of cosmic ray electrons between 300-800 GeV, which was measured locally with the ATIC instrument in balloon flights over Antartica, is universal as expected from dark matter annihilation. Neither does the increase with energy of the fraction of positrons in the cosmic ray flux of electrons in the 10-100 GeV range that was measured by PAMELA imply a dark matter origin: It is consistent with that expected from the sum of the two major sources of Galactic cosmic rays, non relativistic spherical ejecta and highly relativistic jets from supernova explosions.

  6. Detectors of Cosmic Rays, Gamma Rays, and Neutrinos

    SciTech Connect (OSTI)

    Altamirano, A.; Navarra, G.

    2009-04-30

    We summarize the main features, properties and performances of the typical detectors in use in Cosmic Ray Physics. A brief historical and general introduction will focus on the main classes and requirements of such detectors.

  7. High energy cosmic rays, gamma rays and neutrinos from AGN

    E-Print Network [OSTI]

    Yukio Tomozawa

    2008-02-03

    The author reviews a model for the emission of high energy cosmic rays, gamma-rays and neutrinos from AGN (Active Galactic Nuclei) that he has proposed since 1985. Further discussion of the knee energy phenomenon of the cosmic ray energy spectrum requires the existence of a heavy particle with mass in the knee energy range. A possible method of detecting such a particle in the Pierre Auger Project is suggested. Also presented is a relation between the spectra of neutrinos and gamma-rays emitted from AGN. This relation can be tested by high energy neutrino detectors such as ICECUBE, the Mediterranean Sea Detector and possibly by the Pierre Auger Project.

  8. Cosmic-ray acceleration in supernova shocks

    E-Print Network [OSTI]

    Vincent Tatischeff

    2008-07-25

    Galactic cosmic rays are widely believed to be accelerated in expanding shock waves initiated by supernova explosions. The theory of diffusive shock acceleration of cosmic rays is now well established, but two fundamental questions remain partly unanswered: what is the acceleration efficiency, i.e. the fraction of the total supernova energy converted to cosmic-ray energy, and what is the maximum kinetic energy achieved by particles accelerated in supernova explosions? Recent observations of supernova remnants, in X-rays with the Chandra and XMM-Newton satellites and in very-high-energy gamma rays with several ground-based atmospheric Cerenkov telescopes, have provided new pieces of information concerning these two questions. After a review of these observations and their current interpretations, I show that complementary information on the diffusive shock acceleration process can be obtained by studying the radio emission from extragalactic supernovae. As an illustration, a nonlinear model of diffusive shock acceleration is applied to the radio light curves of the supernova SN 1993J, which exploded in the nearby galaxy M81. The results of the model suggest that most of the Galactic cosmic rays may be accelerated during the early phase of interaction between the supernova ejecta and the wind lost from the progenitor star.

  9. Ultra High Energy Cosmic Ray Accelerators

    E-Print Network [OSTI]

    Angela V. Olinto

    1999-11-09

    The surprising lack of a high energy cutoff in the cosmic ray spectrum at the highest energies together with an apparently isotropic distribution of arrival directions have strongly challenged most models proposed for the acceleration of ultra high energy cosmic rays. Young neutron star winds may be able to explain the mystery. We discuss this recent proposal after summarizing the observational challenge and plausible acceleration sites. Young neutrons star winds differ from alternative models in the predictions for composition, spectrum, and angular distribution which will be tested in future experiments.

  10. Cosmic Rays from Supernovae Proven to Hit Earth

    Office of Energy Efficiency and Renewable Energy (EERE)

    A new study confirms that cosmic rays are born in the violent aftermath of supernovas, exploding stars throughout the galaxy.

  11. Numerical likelihood analysis of cosmic ray anisotropies

    SciTech Connect (OSTI)

    Carlos Hojvat et al.

    2003-07-02

    A numerical likelihood approach to the determination of cosmic ray anisotropies is presented which offers many advantages over other approaches. It allows a wide range of statistically meaningful hypotheses to be compared even when full sky coverage is unavailable, can be readily extended in order to include measurement errors, and makes maximum unbiased use of all available information.

  12. Gamma-Ray Bursts, Ultra High Energy Cosmic Rays, and Cosmic Gamma-Ray Background

    E-Print Network [OSTI]

    Tomonori Totani

    1999-04-13

    We argue that gamma-ray bursts (GRBs) may be the origin of the cosmic gamma-ray background radiation observed in GeV range. It has theoretically been discussed that protons may carry a much larger amount of energy than electrons in GRBs, and this large energy can be radiated in TeV range by synchrotron radiation of ultra-high-energy protons (\\sim 10^{20} eV). The possible detection of GRBs above 10 TeV suggested by the Tibet and HEGRA groups also supports this idea. If this is the case, most of TeV gamma-rays from GRBs are absorbed in intergalactic fields and eventually form GeV gamma-ray background, whose flux is in good agreement with the recent observation.

  13. 38th Int. Conf. on Vacuum UV and X-ray Physics - VUVX2013

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    38th Int. Conf. on Vacuum UV and X-ray Physics - VUVX2013 http:vuvx2013.ustc.edu.cndctpage1 12-18 July, 2013; Hefei, China...

  14. Ultrahigh Energy Cosmic Rays: New Physics or Old Physics?

    E-Print Network [OSTI]

    F. W. Stecker

    2004-07-15

    We consider the advantages of and the problems associated with hypotheses to explain the origin of ulthrahigh energy cosmic rays (UHECR: E > 10 EeV) and the "trans GZK" cosmic rays (TGZK: E > 100 EeV), both through "old physics" (acceleration in cosmic sources) and "new physics" (new particles, topological defects, fat neutrino cross sections, Lorentz invariance violation).

  15. The Pierre Auger Cosmic Ray Observatory

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aab, Alexander

    2015-07-08

    The Pierre Auger Observatory, located on a vast, high plain in western Argentina, is the world's largest cosmic ray observatory. The objectives of the Observatory are to probe the origin and characteristics of cosmic rays above 1017 eV and study the interactions of these, the most energetic particles observed in nature. The Auger design features an array of 1660 water Cherenkov particle detector stations spread over 3000 km2 overlooked by 24 air fluorescence telescopes. Additionally, three high elevation fluorescence telescopes overlook a 23.5 km2, 61-detector infilled array with 750 m spacing. The Observatory has been in successful operation since completionmore »in 2008 and has recorded data from an exposure exceeding 40,000 km2 sr yr. This paper describes the design and performance of the detectors, related subsystems and infrastructure that make up the Observatory.« less

  16. The Pierre Auger Cosmic Ray Observatory

    E-Print Network [OSTI]

    ,

    2015-01-01

    The Pierre Auger Observatory, located on a vast, high plain in western Argentina, is the world's largest cosmic ray observatory. The objectives of the Observatory are to probe the origin and characteristics of cosmic rays above $10^{17}$ eV and to study the interactions of these, the most energetic particles observed in nature. The Auger design features an array of 1660 water-Cherenkov particle detector stations spread over 3000 km$^2$ overlooked by 24 air fluorescence telescopes. In addition, three high elevation fluorescence telescopes overlook a 23.5 km$^2$, 61 detector infill array. The Observatory has been in successful operation since completion in 2008 and has recorded data from an exposure exceeding 40,000 km$^2$ sr yr. This paper describes the design and performance of the detectors, related subsystems and infrastructure that make up the Auger Observatory.

  17. The Pierre Auger Cosmic Ray Observatory

    SciTech Connect (OSTI)

    Aab, Alexander

    2015-07-08

    The Pierre Auger Observatory, located on a vast, high plain in western Argentina, is the world's largest cosmic ray observatory. The objectives of the Observatory are to probe the origin and characteristics of cosmic rays above 1017 eV and study the interactions of these, the most energetic particles observed in nature. The Auger design features an array of 1660 water Cherenkov particle detector stations spread over 3000 km2 overlooked by 24 air fluorescence telescopes. Additionally, three high elevation fluorescence telescopes overlook a 23.5 km2, 61-detector infilled array with 750 m spacing. The Observatory has been in successful operation since completion in 2008 and has recorded data from an exposure exceeding 40,000 km2 sr yr. This paper describes the design and performance of the detectors, related subsystems and infrastructure that make up the Observatory.

  18. Solar panels as cosmic-ray detectors

    E-Print Network [OSTI]

    Stella, Carlo; Assis, Pedro; Brogueira, Pedro; Santo, Catarina Espirito; Goncalves, Patricia; Pimenta, Mario; De Angelis, Alessandro

    2014-01-01

    Due to fundamental limitations of accelerators, only cosmic rays can give access to centre-of- mass energies more than one order of magnitude above those reached at the LHC. In fact, extreme energy cosmic rays (1018 eV - 1020 eV) are the only possibility to explore the 100 TeV energy scale in the years to come. This leap by one order of magnitude gives a unique way to open new horizons: new families of particles, new physics scales, in-depth investigations of the Lorentz symmetries. However, the flux of cosmic rays decreases rapidly, being less than one particle per square kilometer per year above 1019 eV: one needs to sample large surfaces. A way to develop large-effective area, low cost, detectors, is to build a solar panel-based device which can be used in parallel for power generation and Cherenkov light detection. Using solar panels for Cherenkov light detection would combine power generation and a non-standard detection device.

  19. An alternative interpretation for cosmic ray peaks

    E-Print Network [OSTI]

    Kim, Doojin

    2015-01-01

    We propose an alternative mechanism based upon dark matter (DM) interpretation for anomalous peak signatures in cosmic ray measurements, assuming an extended dark sector with two DM species. This is contrasted with previous effort to explain various line-like cosmic-ray excesses in the context of DM models where the relevant DM candidate directly annihilates into Standard Model (SM) particles. The heavier DM is assumed to annihilate to an on-shell intermediate state. As the simplest choice, it decays directly into the lighter DM along with an unstable particle which in turn decays to a pair of SM states corresponding to the interesting cosmic anomaly. We show that a sharp continuum energy peak can be readily generated under the proposed DM scenario, depending on dark sector particle mass spectra. Remarkably, such a peak is robustly identified as half the mass of the unstable particle. Furthermore, other underlying mass parameters are analytically related to the shape of energy spectrum. We apply this idea to ...

  20. Ultra High Energy Cosmic Rays: present status and future prospects

    E-Print Network [OSTI]

    A. A. Watson

    2001-12-20

    Reasons for the current interest in cosmic rays above 10^19 eV are described. The latest results on the energy spectrum, arrival direction distribution and mass composition of cosmic rays are reviewed, including data that were reported after the meeting in Blois in June 2001. The enigma set by the existence of ultra high-energy cosmic rays remains. Ideas proposed to explain it are discussed and progress with the construction of the Pierre Auger Observatory is outlined.

  1. Bremsstrahlung Energy Losses for Cosmic Ray Electrons and Positrons

    E-Print Network [OSTI]

    Widom, A; Srivastava, R

    2015-01-01

    Recently cosmic ray electrons and positrons, i.e. cosmic ray charged leptons, have been observed. To understand the distances from our solar system to the sources of such lepton cosmic rays, it is important to understand energy losses from cosmic electrodynamic fields. Energy losses for ultra-relativistic electrons and/or positrons due to classical electrodynamic bremsstrahlung are computed. The energy losses considered are (i) due to Thompson scattering from fluctuating electromagnetic fields in the background cosmic thermal black body radiation and (ii) due to the synchrotron radiation losses from quasi-static domains of cosmic magnetic fields. For distances to sources of galactic length proportions, the lepton cosmic ray energy must be lass than about a TeV.

  2. Bremsstrahlung Energy Losses for Cosmic Ray Electrons and Positrons

    E-Print Network [OSTI]

    A. Widom; J. Swain; R. Srivastava

    2015-09-24

    Recently cosmic ray electrons and positrons, i.e. cosmic ray charged leptons, have been observed. To understand the distances from our solar system to the sources of such lepton cosmic rays, it is important to understand energy losses from cosmic electrodynamic fields. Energy losses for ultra-relativistic electrons and/or positrons due to classical electrodynamic bremsstrahlung are computed. The energy losses considered are (i) due to Thompson scattering from fluctuating electromagnetic fields in the background cosmic thermal black body radiation and (ii) due to the synchrotron radiation losses from quasi-static domains of cosmic magnetic fields. For distances to sources of galactic length proportions, the lepton cosmic ray energy must be lass than about a TeV.

  3. Muon acceleration in cosmic-ray sources

    SciTech Connect (OSTI)

    Klein, Spencer R.; Mikkelsen, Rune E. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Becker Tjus, Julia [Fakultät für Physik and Astronomie, Theoretische Physik I, Ruhr-Universität Bochum, D-44780 Bochum (Germany)

    2013-12-20

    Many models of ultra-high energy cosmic-ray production involve acceleration in linear accelerators located in gamma-ray bursts, magnetars, or other sources. These transient sources have short lifetimes, which necessitate very high accelerating gradients, up to 10{sup 13} keV cm{sup –1}. At gradients above 1.6 keV cm{sup –1}, muons produced by hadronic interactions undergo significant acceleration before they decay. This muon acceleration hardens the neutrino energy spectrum and greatly increases the high-energy neutrino flux. Using the IceCube high-energy diffuse neutrino flux limits, we set two-dimensional limits on the source opacity and matter density, as a function of accelerating gradient. These limits put strong constraints on different models of particle acceleration, particularly those based on plasma wake-field acceleration, and limit models for sources like gamma-ray bursts and magnetars.

  4. The contribution of cosmic rays to global warming

    E-Print Network [OSTI]

    Sloan, Terry

    2011-01-01

    A search has been made for a contribution of the changing cosmic ray intensity to the global warming observed in the last century. The cosmic ray intensity shows a strong 11 year cycle due to solar modulation and the overall rate has decreased since 1900. These changes in cosmic ray intensity are compared to those of the mean global surface temperature to attempt to quantify any link between the two. It is shown that, if such a link exists, the changing cosmic ray intensity contributes less than 8% to the increase in the mean global surface temperature observed since 1900.

  5. High-Energy Cosmic Ray Event Data from the Pierre Auger Cosmic Ray Observatory

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    The Pierre Auger Cosmic Ray Observatory in Mendoza, Argentina is the result of an international collaboration funded by 15 countries and many different organizations. Its mission is to capture high-energy cosmic ray events or air showers for research into their origin and nature. The Pierre Auger Collaboration agreed to make 1% of its data available to the public. The Public Event Explorer is a search tool that allows users to browse or search for and display figures and data plots of events collected since 2004. The repository is updated daily, and, as of June, 2014, makes more than 35,000 events publicly available. The energy of a cosmic ray is measured in Exa electron volts or EeV. These event displays can be browsed in order of their energy level from 0.1 to 41.1 EeV. Each event has an individual identification number.

    The event displays provide station data, cosmic ray incoming direction, various energy measurements, plots, vector-based images, and an ASCII data file.

  6. Galactic cosmic rays on extrasolar Earth-like planets I. Cosmic ray flux

    E-Print Network [OSTI]

    Grießmeier, J -M; Stadelmann, A; Grenfell, J L; Atri, D

    2015-01-01

    (abridged abstract) Theoretical arguments indicate that close-in terrestial exoplanets may have weak magnetic fields, especially in the case of planets more massive than Earth (super-Earths). Planetary magnetic fields, however, constitute one of the shielding layers that protect the planet against cosmic-ray particles. In particular, a weak magnetic field results in a high flux of Galactic cosmic rays that extends to the top of the planetary atmosphere. We wish to quantify the flux of Galactic cosmic rays to an exoplanetary atmosphere as a function of the particle energy and of the planetary magnetic moment. We numerically analyzed the propagation of Galactic cosmic-ray particles through planetary magnetospheres. We evaluated the efficiency of magnetospheric shielding as a function of the particle energy (in the range 16 MeV $\\le$ E $\\le$ 524 GeV) and as a function of the planetary magnetic field strength (in the range 0 ${M}_\\oplus$ $\\le$ {M} $\\le$ 10 ${M}_\\oplus$). Combined with the flux outside the planeta...

  7. THE COSMIC-RAY INTENSITY NEAR THE ARCHEAN EARTH

    SciTech Connect (OSTI)

    Cohen, O.; Drake, J. J.; Kota, J.

    2012-11-20

    We employ three-dimensional state-of-the-art magnetohydrodynamic models of the early solar wind and heliosphere and a two-dimensional model for cosmic-ray transport to investigate the cosmic-ray spectrum and flux near the Archean Earth. We assess how sensitive the cosmic-ray spectrum is to changes in the sunspot placement and magnetic field strength, the large-scale dipole magnetic field strength, the wind ram pressure, and the Sun's rotation period. Overall, our results confirm earlier work that suggested the Archean Earth would have experienced a greatly reduced cosmic-ray flux than is the case today. The cosmic-ray reduction for the early Sun is mainly due to the shorter solar rotation period and tighter winding of the Parker spiral, and to the different surface distribution of the more active solar magnetic field. These effects lead to a global reduction of the cosmic-ray flux at 1 AU by up to two orders of magnitude or more. Variations in the sunspot magnetic field have more effect on the flux than variations in the dipole field component. The wind ram pressure affects the cosmic-ray flux through its influence on the size of the heliosphere via the pressure balance with the ambient interstellar medium. Variations in the interstellar medium pressure experienced by the solar system in orbit through the Galaxy could lead to order of magnitude changes in the cosmic-ray flux at Earth on timescales of a few million years.

  8. Plasmoid impacts on neutron stars and highest energy cosmic rays

    E-Print Network [OSTI]

    C. Litwin; R. Rosner

    2001-04-04

    Particle acceleration by electrostatic polarization fields that arise in plasmas streaming across magnetic fields is discussed as a possible acceleration mechanism of highest-energy cosmic rays. Specifically, plasmoids arising in planetoid impacts onto neutron star magnetospheres are considered. We find that such impacts at plausible rates may account for the observed flux and energy spectrum of the highest energy cosmic rays.

  9. The proposed connection between clouds and cosmic rays: Cloud

    E-Print Network [OSTI]

    The proposed connection between clouds and cosmic rays: Cloud behaviour during the past 50 of cloud factors using both satellite and ground­based data. In particular, we search for evidence for the low cloud decrease predicted by the rising levels of solar activity and the low cloud­cosmic ray flux

  10. CRIME - cosmic ray interactions in molecular environments

    E-Print Network [OSTI]

    Krause, Julian; Gabici, Stefano

    2015-01-01

    Molecular clouds act as targets for cosmic rays (CR), revealing their presence through either gamma-ray emission due to proton-proton interactions, and/or through the ionization level in the cloud, produced by the CR flux. The ionization rate is a unique tool, to some extent complementary to the gamma-ray emission, in that it allows to constrain the CR spectrum especially for energies below the pion production rate ($\\approx 280$ MeV). Here we study the effect of ionization on $H_2$ clouds due to both CR protons and electrons, using the fully relativistic ionization cross sections, which is important to correctly account for the contribution due to relativistic CRs. The contribution to ionization due to secondary electrons is also included self-consistently. The whole calculation has been implemented into a numerical code which is publicly accessible through a web-interface. The code also include the calculation of gamma-ray emission once the CR spectrum

  11. 28th International Cosmic Ray Conference 4065 The Cosmic Ray Shadows of the Moon and the Sun De-

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    28th International Cosmic Ray Conference 4065 The Cosmic Ray Shadows of the Moon and the Sun De of the data shows that the shadows of the sun and moon have each been detected with high significances of the sun is significantly weaker than that of the moon. As expected, the measured positions of the deficits

  12. A Cluster of Ultrahigh Energy Cosmic Rays

    E-Print Network [OSTI]

    Glennys R. Farrar

    2005-03-09

    Five ultrahigh energy cosmic rays in the combined AGASA and HiRes stereo data are analyzed to test whether they come from a single source. The quad above 37 EeV in the 94-event high energy dataset can be analyzed without considering magnetic dispersion. The probability that it is a chance association is 10^-3. Assuming the source is continuous, the random magnetic deflections these UHECRs accumulated en route from their source can be used to estimate \\sqrt{B^2 \\lambda D} ~ 1 nG-Mpc. A quintuplet including a HiRes event between 10 and 30 EeV is well fit with this value. Galactic magnetic deflection appears to be smaller than in some models.

  13. Cosmic Ray Protons Illuminate Dark Matter Axions

    E-Print Network [OSTI]

    H. Tam; Q. Yang

    2011-08-16

    Cosmic ray protons propagating in a spatially-homogeneous but time-dependent field of axions or axion-like particles (ALPs) emit photons in a way that is reminiscent of Cherenkov radiation by charged particles in a preferred background. We compute the emission rate and energy spectrum of the photons, and discuss the possibility of their detection using the Square Kilometre Array which is currently under construction. In the case of a non-detection, constraints can be placed on the parameter space of ALPs whose mass lie between $10^{-7}$eV and $10^{-5}$ eV under the assumption that they are the primary constituent of dark matter.

  14. Selected Results from Ground-Based Cosmic Ray and Gamma-Ray Experiments

    E-Print Network [OSTI]

    N. Magnussen

    1998-05-13

    Selected results from the HEGRA experiment on charged Cosmic Rays and on very high energy gamma-rays are presented. The MAGIC Telescope is presented as an outlook to the future of Gamma-Ray astronomy.

  15. DELAYED GeVTeV PHOTONS FROM GAMMA-RAY BURSTS PRODUCING HIGH-ENERGY COSMIC RAYS

    E-Print Network [OSTI]

    Coppi, Paolo

    DELAYED GeV­TeV PHOTONS FROM GAMMA-RAY BURSTS PRODUCING HIGH-ENERGY COSMIC RAYS ELI WAXMAN A scenario in which cosmic rays (CRs) above 1020 eV are produced by cosmological gamma-ray bursts (GRBs provide information on the IGMF structure. Subject headings: cosmic rays -- gamma rays: bursts -- magnetic

  16. Gamma ray bursts and extreme energy cosmic rays

    SciTech Connect (OSTI)

    Scarsi, Livio

    1998-06-15

    Extreme Energy Cosmic Ray particles (EECR) with E>10{sup 20} eV arriving on Earth with very low flux ({approx}1 particle/Km{sup 2}-1000yr) require for their investigation very large detecting areas, exceeding values of 1000 km{sup 2} sr. Projects with these dimensions are now being proposed: Ground Arrays ('Auger' with 2x3500 km{sup 2} sr) or exploiting the Earth Atmosphere as seen from space ('AIR WATCH' and OWL,'' with effective area reaching 1 million km{sup 2} sr). In this last case, by using as a target the 10{sup 13} tons of air viewed, also the high energy neutrino flux can be investigated conveniently. Gamma Rays Bursts are suggested as a possible source for EECR and the associated High Energy neutrino flux.

  17. Solar Variability, Cosmic Rays and Climate: What's up? The topic of possible relations between solar and cosmic

    E-Print Network [OSTI]

    Usoskin, Ilya G.

    Preface Solar Variability, Cosmic Rays and Climate: What's up? The topic of possible relations between solar and cosmic ray variability on one hand, and Earth's climate on the other hand, is quite in Space Research topical issue on Solar Variability, Cosmic Rays and Climate presents a collection

  18. Cosmic ray lithium isotope measurement with AMS-01

    E-Print Network [OSTI]

    Zhou, Feng, Ph. D. Massachusetts Institute of Technology

    2009-01-01

    The AMS-01 detector measured charged cosmic rays during 10 days on the Space Shuttle Discovery in 1998 and collected 108 events. By identifying 8349 Lithium and 22709 Carbon nuclei from the raw data, this thesis presents ...

  19. What are the Highest Energy Cosmic Rays Telling Us?

    E-Print Network [OSTI]

    cosmic ray astronomy. But they are very rare: ~ 1 per square kilometre per century #12;#12;#12;Post 1966 between these two results. Since then the Telescope Array experiment (TA) in Millard County Utah has

  20. Probing Fukushima with cosmic rays should speed cleanup

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    cosmic rays interact with Earth's atmosphere -- to do its work, providing a simple, passive system that can be used to thwart nuclear smugglers or look inside the cores of...

  1. Introduction to Forward Physics and Cosmic Rays at ISMD 2010

    E-Print Network [OSTI]

    M. Grothe; F. Hautmann; S. Ostapchenko

    2011-03-30

    We give a brief introduction to the topics discussed at the ISMD 2010 Symposium (Antwerp, 2010) on forward physics at the LHC and its interplay with cosmic rays physics.

  2. Strangelets accelerated by pulsars in galactic cosmic rays

    E-Print Network [OSTI]

    K. S. Cheng; V. V. Usov

    2006-11-20

    It is shown that nuggets of strange quark matter may be extracted from the surface of pulsars and accelerated by strong electric fields to high energies if pulsars are strange stars with the crusts, comprised of nuggets embedded in a uniform electron background. Such high energy nuggets called usually strangelets give an observable contribution into galactic cosmic rays and may be detected by the upcoming cosmic ray experiment Alpha Magnetic Spectrometer AMS-02 on the International Space Station.

  3. Strangelets accelerated by pulsars in galactic cosmic rays

    E-Print Network [OSTI]

    Cheng, K S

    2006-01-01

    It is shown that nuggets of strange quark matter may be extracted from the surface of pulsars and accelerated by strong electric fields to high energies if pulsars are strange stars with the crusts, comprised of nuggets embedded in a uniform electron background. Such high energy nuggets called usually strangelets give an observable contribution into galactic cosmic rays and may be detected by the upcoming cosmic ray experiment Alpha Magnetic Spectrometer AMS-02 on the International Space Station.

  4. Strangelets accelerated by pulsars in galactic cosmic rays

    SciTech Connect (OSTI)

    Cheng, K. S. [Department of Physics and Center for Theoretical and Computational Physics, University of Hong Kong, Pok Fu Lam Road, Hong Kong (China); Usov, V. V. [Center for Astrophysics, Weizmann Institute, Rehovot 76100 (Israel)

    2006-12-15

    It is shown that nuggets of strange quark matter may be extracted from the surface of pulsars and accelerated by strong electric fields to high energies if pulsars are strange stars with the crusts, comprised of nuggets embedded in a uniform electron background. Such high energy nuggets called usually strangelets give an observable contribution into galactic cosmic rays and may be detected by the upcoming cosmic ray experiment Alpha Magnetic Spectrometer AMS-02 on the International Space Station.

  5. Fusion of strings and cosmic rays at ultrahigh energies

    E-Print Network [OSTI]

    N. Armesto; M. A. Braun; E. G. Ferreiro; C. Pajares; Yu. M. Shabelski

    1996-02-13

    It is shown that the fusion of strings is a source of particle production in nucleus--nucleus collisions outside the kinematical limits of nucleon--nucleon collisions. This fact, together with another effect of string fusion, the reduction of multiplicities, sheds some light on two of the main problems of ultrahigh energy cosmic rays, the chemical composition and the energy of the most energetic detected cosmic rays.

  6. Cosmogenic Neutrinos from Cosmic Ray Interactions with Extragalactic Infrared Photons

    E-Print Network [OSTI]

    Daniel De Marco; Todor Stanev; F. W. Stecker

    2005-12-19

    We discuss the production of cosmogenic neutrinos on extragalactic infrared photons in a model of its cosmological evolution. The relative importance of these infrared photons as a target for proton interactions is significant, especially in the case of steep injection spectra of the ultrahigh energy cosmic rays. For an E$^{-2.5}$ cosmic ray injection spectrum, for example, the event rate of neutrinos of energy above 1 PeV is more than doubled.

  7. The Cosmic Gamma-Ray Bursts

    E-Print Network [OSTI]

    S. G. Djorgovski; D. A. Frail; S. R. Kulkarni; R. Sari; J. S. Bloom; T. J. Galama; F. A. Harrison; P. A. Price; D. Fox; D. Reichart; S. Yost; E. Berger; A. Diercks; R. Goodrich; F. Chaffee

    2001-06-29

    Cosmic gamma-ray bursts are one of the great frontiers of astrophysics today. They are a playground of relativists and observers alike. They may teach us about the death of stars and the birth of black holes, the physics in extreme conditions, and help us probe star formation in the distant and obscured universe. In this review we summarise some of the remarkable progress in this field over the past few years. While the nature of the GRB progenitors is still unsettled, it now appears likely that at least some bursts originate in explosions of very massive stars, or at least occur in or near the regions of massive star formation. The physics of the burst afterglows is reasonably well understood, and has been tested and confirmed very well by the observations. Bursts are found to be beamed, but with a broad range of jet opening angles; the mean gamma-ray energies after the beaming corrections are ~ 10^51 erg. Bursts are associated with faint ~ 25 mag) galaxies at cosmological redshifts, with ~ 1. The host galaxies span a range of luminosities and morphologies, but appear to be broadly typical for the normal, actively star-forming galaxy populations at comparable redshifts and magnitudes. Some of the challenges for the future include: the nature of the short bursts and possibly other types of bursts and transients; use of GRBs to probe the obscured star formation in the universe, and possibly as probes of the very early universe; and their detection as sources of high-energy particles and gravitational waves.

  8. Maximum entropy analysis of cosmic ray composition

    E-Print Network [OSTI]

    Nosek, Dalibor; Vícha, Jakub; Trávní?ek, Petr; Nosková, Jana

    2016-01-01

    We focus on the primary composition of cosmic rays with the highest energies that cause extensive air showers in the Earth's atmosphere. A way of examining the two lowest order moments of the sample distribution of the depth of shower maximum is presented. The aim is to show that useful information about the composition of the primary beam can be inferred with limited knowledge we have about processes underlying these observations. In order to describe how the moments of the depth of shower maximum depend on the type of primary particles and their energies, we utilize a superposition model. Using the principle of maximum entropy, we are able to determine what trends in the primary composition are consistent with the input data, while relying on a limited amount of information from shower physics. Some capabilities and limitations of the proposed method are discussed. In order to achieve a realistic description of the primary mass composition, we pay special attention to the choice of the parameters of the sup...

  9. A Quantum Phase Transition in the Cosmic Ray Energy Distribution

    E-Print Network [OSTI]

    A. Widom; J. Swain; Y. Srivastava

    2015-02-07

    We here argue that the "knee" of the cosmic ray energy distribution at $E_c \\sim 1$ PeV represents a second order phase transition of cosmic proportions. The discontinuity of the heat capacity per cosmic ray particle is given by $\\Delta c=0.450196\\ k_B$. However the idea of a deeper critical point singularity cannot be ruled out by present accuracy in neither theory nor experiment. The quantum phase transition consists of cosmic rays dominated by bosons for the low temperature phase E E_c$. The low temperature phase arises from those nuclei described by the usual and conventional collective boson models of nuclear physics. The high temperature phase is dominated by protons. The transition energy $E_c$ may be estimated in terms of the photo-disintegration of nuclei.

  10. A Quantum Phase Transition in the Cosmic Ray Energy Distribution

    E-Print Network [OSTI]

    Widom, A; Srivastava, Y

    2015-01-01

    We here argue that the "knee" of the cosmic ray energy distribution at $E_c \\sim 1$ PeV represents a second order phase transition of cosmic proportions. The discontinuity of the heat capacity per cosmic ray particle is given by $\\Delta c=0.450196\\ k_B$. However the idea of a deeper critical point singularity cannot be ruled out by present accuracy in neither theory nor experiment. The quantum phase transition consists of cosmic rays dominated by bosons for the low temperature phase E E_c$. The low temperature phase arises from those nuclei described by the usual and conventional collective boson models of nuclear physics. The high temperature phase is dominated by protons. The transition energy $E_c$ may be estimated in terms of the photo-disintegration of nuclei.

  11. Ultrahigh Energy Cosmic Rays: Facts, Myths, and Legends

    E-Print Network [OSTI]

    Luis Alfredo Anchordoqui

    2011-04-04

    This is a written version of a series of lectures aimed at graduate students in astrophysics/particle theory/particle experiment. In the first part, we explain the important progress made in recent years towards understanding the experimental data on cosmic rays with energies > 10^8 GeV. We begin with a brief survey of the available data, including a description of the energy spectrum, mass composition, and arrival directions. At this point we also give a short overview of experimental techniques. After that, we introduce the fundamentals of acceleration and propagation in order to discuss the conjectured nearby cosmic ray sources, and emphasize some of the prospects for a new (multi-particle) astronomy. Next, we survey the state of the art regarding the ultrahigh energy cosmic neutrinos which should be produced in association with the observed cosmic rays. In the second part, we summarize the phenomenology of cosmic ray air showers. We explain the hadronic interaction models used to extrapolate results from collider data to ultrahigh energies, and describe the prospects for insights into forward physics at the Large Hadron Collider (LHC). We also explain the main electromagnetic processes that govern the longitudinal shower evolution. Armed with these two principal shower ingredients and motivation from the underlying physics, we describe the different methods proposed to distinguish primary species. In the last part, we outline how ultrahigh energy cosmic ray interactions can be used to probe new physics beyond the electroweak scale.

  12. Cosmic-ray induced gamma-ray emission from the starburst galaxy NGC 253

    SciTech Connect (OSTI)

    Wang, Xilu; Fields, Brian D.

    2014-05-09

    Cosmic rays in galaxies interact with the interstellar medium and give us a direct view of nuclear and particle interactions in the cosmos. For example, cosmic-ray proton interactions with interstellar hydrogen produce gamma rays via PcrPism??{sup 0}???. For a 'normal' star-forming galaxy like the Milky Way, most cosmic rays escape the Galaxy before such collisions, but in starburst galaxies with dense gas and huge star formation rate, most cosmic rays do suffer these interactions [1,2]. We construct a 'thick-target' model for starburst galaxies, in which cosmic rays are accelerated by supernovae, and escape is neglected. This model gives an upper limit to the gamma-ray emission. Only two free parameters are involved in the model: cosmic-ray proton acceleration energy rate from supernova and the proton injection spectral index. The pionic gamma-radiation is calculated from 10 MeV to 10 TeV for the starburst galaxy NGC 253, and compared to Fermi and HESS data. Our model fits NGC 253 well, suggesting that cosmic rays in this starburst are in the thick target limit, and that this galaxy is a gamma-ray calorimeter.

  13. Sgoldstinos: Primaries of Ultra-High Energy Cosmic Rays

    E-Print Network [OSTI]

    D. S. Gorbunov

    2002-05-30

    I describe supersymmetric extensions of the Standard Model with light sgoldstinos and discuss the explanation of Ultra High Energy Cosmic Rays above GZK cutoff in these models. Also I briefly discuss the possibility to solve other cosmological and astrophysical puzzles, such as gamma-ray bursts and dimming of high-redshift supernovae, within the models with light sgoldstinos.

  14. Are gamma-ray bursts the sources of ultra-high energy cosmic rays?

    E-Print Network [OSTI]

    Philipp Baerwald; Mauricio Bustamante; Walter Winter

    2014-07-07

    We reconsider the possibility that gamma-ray bursts (GRBs) are the sources of the ultra-high energy cosmic rays (UHECRs) within the internal shock model, assuming a pure proton composition of the UHECRs. For the first time, we combine the information from gamma-rays, cosmic rays, prompt neutrinos, and cosmogenic neutrinos quantitatively in a joint cosmic ray production and propagation model, and we show that the information on the cosmic energy budget can be obtained as a consequence. In addition to the neutron model, we consider alternative scenarios for the cosmic ray escape from the GRBs, i.e., that cosmic rays can leak from the sources. We find that the dip model, which describes the ankle in UHECR observations by the pair production dip, is strongly disfavored in combination with the internal shock model because a) unrealistically high baryonic loadings (energy in protons versus energy in electrons/gamma-rays) are needed for the individual GRBs and b) the prompt neutrino flux easily overshoots the corresponding neutrino bound. On the other hand, GRBs may account for the UHECRs in the ankle transition model if cosmic rays leak out from the source at the highest energies. In that case, we demonstrate that future neutrino observations can efficiently test most of the parameter space -- unless the baryonic loading is much larger than previously anticipated.

  15. Extragalactic cosmic ray self-confinement around sources

    E-Print Network [OSTI]

    Blasi, P; D'Angelo, M

    2015-01-01

    Most models of the origin of ultra high energy cosmic rays rely on the existence of luminous extragalactic sources. Cosmic rays escaping the galaxy where the source is located produce a sufficiently large electric current to justify the investigation of plasma instabilities induced by such current. Most interesting is the excitation of modes that lead to production of magnetic perturbations that may scatter particles thereby hindering their escape, or at least changing the propagation mode of escaping cosmic rays. We argue that self-generation of waves may force cosmic rays to be confined in the source proximity for energies $E\\lesssim 10^{7} L_{44}^{2/3}$ GeV for low background magnetic fields ($B_{0}\\ll nG$). For larger values of $B_{0}$, cosmic rays are confined close to their sources for energies $E\\lesssim 2\\times 10^{8} \\lambda_{10} L_{44}^{1/4} B_{-10}^{1/2}$ GeV, where $B_{-10}$ is the field in units of $0.1$ nG, $\\lambda_{10}$ is its coherence length in units of 10 Mpc and $L_{44}$ is the source lumi...

  16. Are ultrahigh energy cosmic rays signals of supersymmetry?

    E-Print Network [OSTI]

    Daniel J. H. Chung; Glennys R. Farrar; Edward W. Kolb

    1997-12-19

    We investigate the possibility that cosmic rays of energy larger than the Greisen-Zatsepin-Kuzmin cutoff are not nucleons, but a new stable, massive, hadron that appears in many extensions of the standard model. We focus primarily on the S^0, a uds-gluino bound state. The range of the S^0 through the cosmic background radiation is significantly longer than the range of nucleons, and therefore can originate from sources at cosmoglogical distances.

  17. High Energy Neutrino Astronomy - the cosmic-ray connection

    E-Print Network [OSTI]

    Thomas K. Gaisser

    2000-11-28

    Several of the models for origin of the highest energy cosmic rays also predict significant neutrino fluxes. A common factor of the models is that they must provide sufficient power to supply the observed energy in the extragalactic component of the cosmic radiation. The assumption that a comparable amount of energy goes into high-energy neutrinos allows a model-independent estimate of the neutrino signal that may be expected.

  18. Chemical Composition of Galactic Cosmic Rays with Space Experiments

    E-Print Network [OSTI]

    Mirko Boezio; Emiliano Mocchiutti

    2012-08-07

    The origin and properties of the cosmic radiation are one of the most intriguing question in modern astrophysics. The precise measurement of the chemical composition and energy spectra of the cosmic rays provides fundamental insight into these subjects. In this paper we will review the existing experimental data. Specifically, we will analyse results collected by space-born experiments discussing the experimental uncertainties and challenges with a focus on the PAMELA experiment.

  19. ORIGIN OF THE COSMIC-RAY SPECTRAL HARDENING

    SciTech Connect (OSTI)

    Tomassetti, Nicola, E-mail: nicola.tomassetti@pg.infn.it [INFN-Sezione di Perugia, 06122 Perugia (Italy)

    2012-06-10

    Recent data from ATIC, CREAM, and PAMELA indicate that the cosmic-ray energy spectra of protons and nuclei exhibit a remarkable hardening at energies above 100 GeV nucleon{sup -1}. We propose that the hardening is an interstellar propagation effect that originates from a spatial change of the cosmic-ray transport properties in different regions of the Galaxy. The key hypothesis is that the diffusion coefficient is not separable into energy and space variables as usually assumed. Under this scenario, we can reproduce the observational data well. Our model has several implications for cosmic-ray acceleration/propagation physics and can be tested by ongoing experiments such as the Alpha Magnetic Spectrometer or Fermi-LAT.

  20. Pinpointing Cosmic Ray Propagation With The AMS-02 Experiment

    E-Print Network [OSTI]

    Pato, Miguel; Simet, Melanie

    2010-01-01

    The Alpha Magnetic Spectrometer (AMS-02), which is scheduled to be deployed onboard the International Space Station later this year, will be capable of measuring the composition and spectra of GeV-TeV cosmic rays with unprecedented precision. In this paper, we study how the projected measurements from AMS-02 of stable secondary-to-primary and unstable ratios (such as boron-to-carbon and beryllium-10-to-beryllium-9) can constrain the models used to describe the propagation of cosmic rays throughout the Milky Way. We find that within the context of fairly simple propagation models, all of the model parameters can be determined with high precision from the projected AMS-02 data. Such measurements are less constraining in more complex scenarios, however, which allow for departures from a power-law form for the diffusion coefficient, for example, or for inhomogeneity or stochasticity in the distribution and chemical abundances of cosmic ray sources.

  1. Pinpointing cosmic ray propagation with the AMS-02 experiment

    SciTech Connect (OSTI)

    Pato, Miguel [Dipartimento di Fisica, Universitŕ degli Studi di Padova, via Marzolo 8, I-35131, Padova (Italy); Hooper, Dan [Center for Particle Astrophysics, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Simet, Melanie, E-mail: pato@iap.fr, E-mail: dhooper@fnal.gov, E-mail: msimet@uchicago.edu [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States)

    2010-06-01

    The Alpha Magnetic Spectrometer (AMS-02), which is scheduled to be deployed onboard the International Space Station later this year, will be capable of measuring the composition and spectra of GeV-TeV cosmic rays with unprecedented precision. In this paper, we study how the projected measurements from AMS-02 of stable secondary-to-primary and unstable ratios (such as boron-to-carbon and beryllium-10-to-beryllium-9) can constrain the models used to describe the propagation of cosmic rays throughout the Milky Way. We find that within the context of fairly simple propagation models, all of the model parameters can be determined with high precision from the projected AMS-02 data. Such measurements are less constraining in more complex scenarios, however, which allow for departures from a power-law form for the diffusion coefficient, for example, or for inhomogeneity or stochasticity in the distribution and chemical abundances of cosmic ray sources.

  2. Cosmic ray transport and anisotropies to high energies

    E-Print Network [OSTI]

    Biermann, P L; Meli, A; Nath, B N; Seo, E -S; de Souza, V; Tjus, J Becker

    2015-01-01

    A model is introduced, in which the irregularity spectrum of the Galactic magnetic field beyond the dissipation length scale is first a Kolmogorov spectrum $k^{-5/3}$ at small scales $\\lambda \\, = \\, 2 \\pi/k$ with $k$ the wave-number, then a saturation spectrum $k^{-1}$, and finally a shock-dominated spectrum $k^{-2}$ mostly in the halo/wind outside the Cosmic Ray disk. In an isotropic approximation such a model is consistent with the Interstellar Medium (ISM) data. With this model we discuss the Galactic Cosmic Ray (GCR) spectrum, as well as the extragalactic Ultra High Energy Cosmic Rays (UHECRs), their chemical abundances and anisotropies. UHECRs may include a proton component from many radio galaxies integrated over vast distances, visible already below 3 EeV.

  3. A Cosmic Ray Resolution to the Superbubble Energy-Crisis

    E-Print Network [OSTI]

    Yousaf M. Butt; Andrei M. Bykov

    2008-02-26

    Superbubbles (SBs) are amongst the greatest injectors of energy into the Galaxy, and have been proposed to be the acceleration site of Galactic cosmic rays. They are thought to be powered by the fast stellar winds and powerful supernova explosions of massive stars in dense stellar clusters and associations. Observations of the SB 'DEM L192' in the neighboring Large Magellenic Cloud (LMC) galaxy show that it contains only about one-third the energy injected by its constituent stars via fast stellar winds and supernovae. It is not yet understood where the excess energy is going, thus, the so-called 'energy crisis'. We show here that it is very likely that a significant fraction of the unaccounted for energy is being taken up in accelerating cosmic rays, thus bolstering the argument for the SB origin of cosmic rays.

  4. A Cosmic Ray Resolution to the Superbubble Energy-Crisis

    E-Print Network [OSTI]

    Butt, Yousaf M

    2008-01-01

    Superbubbles (SBs) are amongst the greatest injectors of energy into the Galaxy, and have been proposed to be the acceleration site of Galactic cosmic rays. They are thought to be powered by the fast stellar winds and powerful supernova explosions of massive stars in dense stellar clusters and associations. Observations of the SB 'DEM L192' in the neighboring Large Magellenic Cloud (LMC) galaxy show that it contains only about one-third the energy injected by its constituent stars via fast stellar winds and supernovae. It is not yet understood where the excess energy is going, thus, the so-called 'energy crisis'. We show here that it is very likely that a significant fraction of the unaccounted for energy is being taken up in accelerating cosmic rays, thus bolstering the argument for the SB origin of cosmic rays.

  5. Energy spectrum of ultra high energy cosmic rays

    E-Print Network [OSTI]

    Ioana C. Maris; for the Pierre Auger Collaboration

    2008-08-12

    The construction of the southern site of the Pierre Auger Observatory is almost completed. Three independent measurements of the flux of the cosmic rays with energies larger than 1 EeV have been performed during the construction phase. The surface detector data collected until August 2007 have been used to establish a flux suppression at the highest energies with a 6 sigma significance. The observations of cosmic rays by the fluorescence detector allowed the extension of the energy spectrum to lower energies, where the efficiency of the surface detector is less than 100% and a change in the spectral index is expected.

  6. ISOTOPIC COMPOSITION OF LIGHT NUCLEI IN COSMIC RAYS: RESULTS FROM AMS-01

    E-Print Network [OSTI]

    Becker, R.

    The variety of isotopes in cosmic rays allows us to study different aspects of the processes that cosmic rays undergo between the time they are produced and the time of their arrival in the heliosphere. In this paper, we ...

  7. Plasma Wakefield Acceleration for Ultrahigh Energy Cosmic Rays

    E-Print Network [OSTI]

    Pisin Chen; Toshiki Tajima; Yoshiyuki Takahashi

    2002-05-21

    A cosmic acceleration mechanism is introduced which is based on the wakefields excited by the Alfven shocks in a relativistically flowing plasma, where the energy gain per distance of a test particle is Lorentz invariant. We show that there exists a threshold condition for transparency below which the accelerating particle is collision-free and suffers little energy loss in the plasma medium. The stochastic encounters of the random accelerating-decelerating phases results in a power-law energy spectrum: f(e) 1/e^2. The environment suitable for such plasma wakefield acceleration can be cosmically abundant. As an example, we discuss the possible production of super-GZK ultra high energy cosmic rays (UHECR) through this mechanism in the atmosphere of gamma ray bursts. We show that the acceleration gradient can be as high as G ~ 10^16 eV/cm. The estimated event rate in our model agrees with that from UHECR observations.

  8. Ultra high energy cosmic rays: the highest energy frontier

    E-Print Network [OSTI]

    Neto, Joăo R T de Mello

    2015-01-01

    Ultra-high energy cosmic rays (UHECRs) are the highest energy messengers of the present universe, with energies up to $10^{20}$ eV. Studies of astrophysical particles (nuclei, electrons, neutrinos and photons) at their highest observed energies have implications for fundamental physics as well as astrophysics. The primary particles interact in the atmosphere and generate extensive air showers. Analysis of those showers enables one not only to estimate the energy, direction and most probable mass of the primary cosmic particles, but also to obtain information about the properties of their hadronic interactions at an energy more than one order of magnitude above that accessible with the current highest energy human-made accelerator. In this contribution we will review the state-of-the-art in UHECRs detection. We will present the leading experiments Pierre Auger Observatory and Telescope Array and discuss the cosmic ray energy spectrum, searches for directional anisotropy, studies of mass composition, the determ...

  9. Galactic modulation of extragalactic cosmic rays -Alternative scenario of the origin of the knee -

    E-Print Network [OSTI]

    Galactic modulation of extragalactic cosmic rays - Alternative scenario of the origin of the knee is reproduced well again. The energy dependence of mean mass of cosmic rays above the knee energy is presented to be compared with observations. . 1. Introduction Cosmic rays (CRs) with energies below the knee have been

  10. CAN COSMIC-RAY NUCLEON MEASUREMENTS BE USED TO SCALE PRODUCTION RATES OF COSMOGENIC NUCLIDES?

    E-Print Network [OSTI]

    Zreda, Marek

    CAN COSMIC-RAY NUCLEON MEASUREMENTS BE USED TO SCALE PRODUCTION RATES OF COSMOGENIC NUCLIDES variability of nuclide production rates on the earth's surface. Direct measurements of cosmic-ray fluxes have spatial variations of cosmic-ray neu- tron intensity and production rates of in-situ cosmogenic nuclides

  11. Determination of ultra high-energy cosmic ray composition using surface detector parameters

    E-Print Network [OSTI]

    van Suijlekom, Walter

    know that sources of low-energy cosmic rays are stars like our sun. For high energy cosmic raysDetermination of ultra high-energy cosmic ray composition using surface detector parameters Marie This bachelor thesis is the result of my Bachelor project at the department of Experimental High Energy Physics

  12. 28th International Cosmic Ray Conference 2293 Search for Extremely High Energy Gamma Rays with the

    E-Print Network [OSTI]

    Hörandel, Jörg R.

    their directions of incidence points back to their points of production. The highest gamma ray energies identified28th International Cosmic Ray Conference 2293 Search for Extremely High Energy Gamma Rays, 76021 Karlsruhe, Germany (2) Institut f¨ur Kernphysik, Forschungszentrum Karlsruhe, 76021 Karlsruhe

  13. Reference Radiation for Cosmic Rays in RBE Research 

    E-Print Network [OSTI]

    Feng, Shaoyong

    2011-10-21

    effectiveness relative to a specific radiation is usually used. For low energy heavy ions and neutrons 250 keV photons are usually used for the reference radiation but their depth dose distribution is very different from that for cosmic rays. In this research...

  14. Observing The Cosmic Ray Moon Shadow With VERITAS

    E-Print Network [OSTI]

    Bird, Ralph

    2015-01-01

    The Earth is subjected to a uniform flux of very-high-energy (VHE, E > 100 GeV) cosmic rays unless they are obscured by an object, such as the Moon, in which case a deficit or shadow is created. Since cosmic rays are charged this deficit is deflected by the Earth's magnetic field, enabling the rigidity of the obstructed cosmic rays to be determined. Measurement of the relative deficits of different species enables the positron fraction and the antiproton ratio to be measured. The April 15, 2014 lunar eclipse was visible with the VERITAS Cherenkov telescopes, which allowed (with special UV bandpass filters) 74 minutes of direct observations of the Moon and the associated deficit in the cosmic-ray flux. The results of this observation are presented. In addition VERITAS has been conducting a series of observations by pointing close to a partially illuminated Moon, with a reduced photomultiplier tube high voltage and UV bandpass filters. We present the technique developed for these observations and their current ...

  15. The Galactic cosmic-ray Sun shadow observed by HAWC

    E-Print Network [OSTI]

    Enriquez, O

    2015-01-01

    The magnetic field of the Solar corona is difficult to measure directly. However, indirect observations of the solar corona are possible using the deficit in flux of cosmic rays coming from the direction of the Sun. Low-energy cosmic rays (~GeV) are deflected by the inner magnetic field of the Sun and the interplanetary magnetic field frozen into the solar wind. In contrast, high-energy cosmic rays (~TeV and above) are absorbed in the Sun's photosphere producing a shadow in the Sun's nominal position viewed from Earth. Several ground-based instruments have observed the effects of the heliospheric magnetic field on the size of the sun shadow and its position. The High-Altitude Water Cherenkov Observatory (HAWC) is an air shower array located in the central region of Mexico that observes TeV cosmic rays at a rate of about 15 kHz. in this work, we present preliminary images of the sun shadow from data collected by HAWC during 2013 and 2014 for different energy ranges.

  16. The transport of cosmic rays across magnetic fieldlines

    SciTech Connect (OSTI)

    Desiati, Paolo [Wisconsin IceCube Particle Astrophysics Center (WIPAC) and Department of Astronomy, University of Wisconsin-Madison, 222 West Washington Avenue, Madison, WI 53703 (United States); Zweibel, Ellen G., E-mail: desiati@wipac.wisc.edu, E-mail: zweibel@astro.wisc.edu [Departments of Astronomy and Physics, Center for Magnetic Self-Organization, University of Wisconsin-Madison, 475 North Charter Street, Madison, WI 53706 (United States)

    2014-08-10

    The long residence times and small anisotropies of cosmic rays suggest that they are well confined and well scattered by the Galactic magnetic field. Due to the disk-like shape of the confinement volume, transport in the vertical direction, which is perpendicular to the mean Galactic magnetic field, is key to cosmic ray escape. It has long been recognized that this vertical transport depends both on the vertical component of the field lines themselves and on the extent to which the cosmic rays are tied to the field lines. In this paper, we use magnetic fields with very simple spatial and temporal structures to isolate some important features of cross field line transport. We show that even simple magnetic nonuniformities combined with pitch angle scattering can enhance cross field line transport by several orders of magnitude, while pitch angle scattering is unnecessary for enhanced transport if the field is chaotic. Nevertheless, perpendicular transport is much less than parallel transport in all the cases we study. We apply the results to confinement of cosmic rays in the Fermi bubbles.

  17. Constraints on the Cosmic-Ray Density Gradient Beyond the Solar...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Constraints on the Cosmic-Ray Density Gradient Beyond the Solar Circle From Fermi Gamma-Ray Observations of the Third Galactic Quadrant Citation Details...

  18. On the Origin of Ultra High Energy Cosmic Rays

    SciTech Connect (OSTI)

    Fowler, T; Colgate, S; Li, H

    2009-07-01

    Turbulence-driven plasma accelerators produced by magnetized accretion disks around black holes are proposed as the mechanism mainly responsible for observed cosmic ray protons with ultra high energies 10{sup 19}-10{sup 21} eV. The magnetized disk produces a voltage comparable to these cosmic ray energies. Here we present a Poynting model in which this voltage provides all of the energy to create the jet-like structures observed to be ejected from accretion disks, and this voltage also accelerates ions to high energies at the top of the expanding structure. Since the inductive electric field E = -v x B driving expansion has no component parallel to the magnetic field B, ion acceleration requires plasma wave generation - either a coherent wave accelerator as recently proposed, or instability-driven turbulence. We find that turbulence can tap the full inductive voltage as a quasi-steady accelerator, and even higher energies are produced by transient events on this structure. We find that both MHD modes due to the current and ion diffusion due to kinetic instability caused by the non-Maxwellian ion distribution contribute to acceleration. We apply our results to extragalactic giant radiolobes, whose synchrotron emissions serve to calibrate the model, and we discuss extrapolating to other astrophysical structures. Approximate calculations of the cosmic ray intensity and energy spectrum are in rough agreement with data and serve to motivate more extensive MHD and kinetic simulations of turbulence that could provide more accurate cosmic ray and synchrotron spectra to be compared with observations. A distinctive difference from previous models is that the cosmic ray and synchrotron emissions arise from different parts of the magnetic structure, thus providing a signature for the model.

  19. On the Origin of Ultra High Energy Cosmic Rays II

    SciTech Connect (OSTI)

    Fowler, T K; Colgate, S; Li, H; Bulmer, R H; Pino, J

    2011-03-08

    We show that accretion disks around Active Galactic Nuclei (AGNs) could account for the enormous power in observed ultra high energy cosmic rays {approx}10{sup 20} eV (UHEs). In our model, cosmic rays are produced by quasi-steady acceleration of ions in magnetic structures previously proposed to explain jets around Active Galactic Nuclei with supermassive black holes. Steady acceleration requires that an AGN accretion disk act as a dynamo, which we show to follow from a modified Standard Model in which the magnetic torque of the dynamo replaces viscosity as the dominant mechanism accounting for angular momentum conservation during accretion. A black hole of mass M{sub BH} produces a steady dynamo voltage V {proportional_to} {radical}M{sub BH} giving V {approx} 10{sup 20} volts for M{sub BH} {approx} 10{sup 8} solar masses. The voltage V reappears as an inductive electric field at the advancing nose of a dynamo-driven jet, where plasma instability inherent in collisionless runaway acceleration allows ions to be steadily accelerated to energies {approx} V, finally ejected as cosmic rays. Transient events can produce much higher energies. The predicted disk radiation is similar to the Standard Model. Unique predictions concern the remarkable collimation of jets and emissions from the jet/radiolobe structure. Given MBH and the accretion rate, the model makes 7 predictions roughly consistent with data: (1) the jet length; (2) the jet radius; (3) the steady-state cosmic ray energy spectrum; (4) the maximum energy in this spectrum; (5) the UHE cosmic ray intensity on Earth; (6) electron synchrotron wavelengths; and (7) the power in synchrotron radiation. These qualitative successes motivate new computer simulations, experiments and data analysis to provide a quantitative verification of the model.

  20. Observation of Anisotropy in the Arrival Direction Distribution of TeV Cosmic Rays with HAWC

    E-Print Network [OSTI]

    BenZvi, S Y; Westerhoff, S

    2015-01-01

    The High-Altitude Water Cherenkov (HAWC) Observatory, located 4100 m above sea level near Sierra Negra (19$^\\circ$ N) in Mexico, is sensitive to gamma rays and cosmic rays at TeV energies. The arrival direction distribution of cosmic rays at these energies shows significant anisotropy on several angular scales, with a relative intensity ranging between 10$^{-3}$ and 10$^{-4}$. We present the results of a study of cosmic-ray anisotropy based on more than 86 billion cosmic-ray air showers recorded with HAWC since June 2013. The HAWC cosmic-ray sky map, which has a median energy of 2 TeV, exhibits several regions of significantly enhanced cosmic-ray flux. We present the energy dependence of the anisotropy and the cosmic-ray spectrum in the regions of significant excess.

  1. Are ultrahigh energy cosmic rays a signal for supersymmetry?

    SciTech Connect (OSTI)

    Chung, D.J. [Department of Physics and Enrico Fermi Institute, The University of Chicago, Chicago, Illinois 60637 (United States)] [Department of Physics and Enrico Fermi Institute, The University of Chicago, Chicago, Illinois 60637 (United States); [NASA/Fermilab Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); Farrar, G.R. [Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08855 (United States)] [Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08855 (United States); Kolb, E.W. [NASA/Fermilab Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)] [NASA/Fermilab Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); [Department of Astronomy and Astrophysics and Enrico Fermi Institute, The University of Chicago, Chicago, Illinois 60637 (United States)

    1998-04-01

    We investigate the possibility that cosmic rays of energy larger than the Greisen-Zatsepin-Kuzmin cutoff are not nucleons, but a new stable, massive, hadron that appears in many extensions of the standard model. We focus primarily on the S{sup 0}, a uds-gluino bound state. The range of the S{sup 0} through the cosmic background radiation is significantly longer than the range of nucleons, and therefore S{sup 0}{close_quote}s can originate from sources at cosmological distances. {copyright} {ital 1998} {ital The American Physical Society}

  2. CMS Data Processing Workflows during an Extended Cosmic Ray Run

    SciTech Connect (OSTI)

    Not Available

    2009-11-01

    The CMS Collaboration conducted a month-long data taking exercise, the Cosmic Run At Four Tesla, during October-November 2008, with the goal of commissioning the experiment for extended operation. With all installed detector systems participating, CMS recorded 270 million cosmic ray events with the solenoid at a magnetic field strength of 3.8 T. This paper describes the data flow from the detector through the various online and offline computing systems, as well as the workflows used for recording the data, for aligning and calibrating the detector, and for analysis of the data.

  3. CAN ULTRAHIGH-ENERGY COSMIC RAYS COME FROM GAMMA-RAY BURSTS? COSMIC RAYS BELOW THE ANKLE AND GALACTIC GAMMA-RAY BURSTS

    SciTech Connect (OSTI)

    Eichler, David [Physics Department, Ben-Gurion University, Be'er-Sheva 84105 (Israel); Pohl, Martin [Institut fuer Physik und Astronomie, Universitaet Potsdam, 14476 Potsdam-Golm (Germany)

    2011-09-10

    The maximum cosmic-ray energy achievable by acceleration by a relativistic blast wave is derived. It is shown that forward shocks from long gamma-ray bursts (GRBs) in the interstellar medium accelerate protons to large enough energies, and have a sufficient energy budget, to produce the Galactic cosmic-ray component just below the ankle at 4 x 10{sup 18} eV, as per an earlier suggestion. It is further argued that, were extragalactic long GRBs responsible for the component above the ankle as well, the occasional Galactic GRB within the solar circle would contribute more than the observational limits on the outward flux from the solar circle, unless an avoidance scenario, such as intermittency and/or beaming, allows the present-day local flux to be less than 10{sup -3} of the average. Difficulties with these avoidance scenarios are noted.

  4. Time correlation of cosmic-ray-induced neutrons and gamma rays at sea level

    E-Print Network [OSTI]

    Harilal, S. S.

    Time correlation of cosmic-ray-induced neutrons and gamma rays at sea level G. Miloshevsky n , A and evaporation processes of air nuclei are time-correlated. The occurrence of their counts in a fixed time interval is not a random (Poisson) distribution, but rather time-correlated bursts of counts

  5. A New Measurement of Cosmic Ray Composition at the Knee

    E-Print Network [OSTI]

    K. Boothby; M. Chantell; K. D. Green; D. B. Kieda; J. Knapp; C . G. Larsen; S. P. Swordy

    1997-10-15

    The Dual Imaging Cerenkov Experiment (DICE) was designed and operated for making elemental composition measurements of cosmic rays near the knee of the spectrum at several PeV. Here we present the first results using this experiment from the measurement of the average location of the depth of shower maximum, , in the atmosphere as a function of particle energy. The value of near the instrument threshold of ~0.1 PeV is consistent with expectations from previous direct measurements. At higher energies there is little change in composition up to ~5 PeV. Above this energy is deeper than expected for a constant elemental composition implying the overall elemental composition is becoming lighter above the knee region. These results disagree with the idea that cosmic rays should become on average heavier above the knee. Instead they suggest a transition to a qualitatively different population of particles above 5 PeV.

  6. Extragalactic Magnetic Field and the Highest Energy Cosmic Rays

    E-Print Network [OSTI]

    Sangjin Lee; Angela Olinto; Guenter Sigl

    1995-08-21

    The strength and spectrum of the extragalactic magnetic field are still unknown. Its measurement would help answer the question of whether galactic fields are purely a primordial relic or were dynamically enhanced from a much smaller cosmological seed field. In this letter, we show that the composition, spectrum, and directional distribution of extragalactic ultrahigh energy cosmic rays with energies above $\\simeq 10^{18}\\ev$ can probe the large scale component of the extragalactic magnetic field below the present observational upper limit of $10^{-9}$ Gauss. Cosmic ray detectors under construction or currently in the proposal stage should be able to test the existence of the extragalactic magnetic fields on scales of a few to tens of Mpc and strengths in the range $\\simeq 10^{-10} - 10^{-9}$ Gauss.

  7. KCDC - The KASCADE Cosmic-ray Data Centre

    E-Print Network [OSTI]

    Haungs, A; Fuchs, B; Kang, D; Schoo, S; Wochele, D; Wochele, J; Apel, W D; Arteaga-Velazquez, J C; Bekk, K; Bertaina, M; Bozdog, H; Brancus, I M; Cantoni, E; Chiavassa, A; Cossavella, F; Daumiller, K; de Souza, V; Di Pierro, F; Doll, P; Engel, R; Fuhrmann, D; Gherghel-Lascu, A; Gils, H J; Glasstetter, R; Grupen, C; Heck, D; Hoerandel, J R; Huber, D; Huege, T; Kampert, K H; Klages, H O; Link, K; Luczak, P; Mathes, H J; Mayer, H J; Milke, J; Mitrica, B; Morello, C; Oehlschlaeger, J; Ostapchenko, S; Palmieri, N; Petcu, M; Pierog, T; Rebel, H; Roth, M; Schieler, H; Schroeder, F G; Sima, O; Toma, G; Trinchero, G C; Ulrich, H; Weindl, A; Zabierowski, J

    2015-01-01

    KCDC, the KASCADE Cosmic-ray Data Centre, is a web portal, where data of astroparticle physics experiments will be made available for the interested public. The KASCADE experiment, financed by public money, was a large-area detector for the measurement of high-energy cosmic rays via the detection of air showers. KASCADE and its extension KASCADE-Grande stopped finally the active data acquisition of all its components including the radio EAS experiment LOPES end of 2012 after more than 20 years of data taking. In a first release, with KCDC we provide to the public the measured and reconstructed parameters of more than 160 million air showers. In addition, KCDC provides the conceptional design, how the data can be treated and processed so that they are also usable outside the community of experts in the research field. Detailed educational examples make a use also possible for high-school students and early stage researchers.

  8. Exotic massive hadrons and ultra-high energy cosmic rays

    E-Print Network [OSTI]

    Ivone F. M. Albuquerque; Glennys R. Farrar; Edward W. Kolb

    1998-10-02

    We investigate the proposal that primary cosmic rays of energy above the Greisen-Zatsepin-Kuzmin cutoff are exotic massive strongly interacting particles (uhecrons). We study the properties of air showers produced by uhecrons and find that masses in excess of about 50 GeV are inconsistent with the highest energy event observed. We also estimate that with sufficient statistics a uhecron of mass as low as 10 GeV may be distinguished from a proton.

  9. Dark Matter and Cosmic Rays from Light Gauginos

    E-Print Network [OSTI]

    Glennys R. Farrar

    1997-04-13

    An attractive class of SUSY-breaking mechanisms predicts a photino mass of order 1 GeV. Relic photinos can naturally account for the observed dark matter. Detection of these light photinos is discussed and contrasted with conventional WIMPs. In this scenario the gluino mass is about 100 MeV. The lightest gluino-containing baryon could account for the recently observed ultra-high energy cosmic rays, which violate the GZK bound.

  10. High Energy Cosmic Rays from Local GRBs Armen Atoyan1

    E-Print Network [OSTI]

    High Energy Cosmic Rays from Local GRBs Armen Atoyan1 and Charles D. Dermer2 1 CRM, Universit´e de Montr´eal, Montr´eal, Canada H3C 3J7; atoyan@crm.umontreal.ca 2 NRL, Code 7653, Washington, DC 20375 with energies E between 0.1 - 1 PeV and the energy of the second knee at E2 3 � 1017 eV as originating from

  11. Double Pair Production by Ultra High Energy Cosmic Ray Photons

    E-Print Network [OSTI]

    S. V. Demidov; O. E. Kalashev

    2008-12-22

    With use of CompHEP package we've made the detailed estimate of the influence of double e+e- pair production by photons (DPP) on the propagation of ultra high energy electromagnetic cascade. We show that in the models in which cosmic ray photons energy reaches few thousand EeV refined DPP analysis may lead to substantial difference in predicted photon spectrum compared to previous rough estimates.

  12. Preheating of the Universe by cosmic rays from primordial supernovae at the beginning of cosmic reionization

    E-Print Network [OSTI]

    Sazonov, Sergey

    2015-01-01

    The 21-cm signal from the cosmic reionization epoch can shed light on the history of heating of the primordial intergalactic medium (IGM) at z~30-10. It has been suggested that X-rays from the first accreting black holes could significantly heat the Universe at these early epochs. Here we propose another IGM heating mechanism associated with the first stars. As known from previous work, the remnants of powerful supernovae (SNe) ending the lives of massive Population III stars could readily expand out of their host dark matter minihalos into the surrounding IGM, aided by the preceeding photoevaporation of the halo's gas by the UV radiation from the progenitor star. We argue that during the evolution of such a remnant a significant fraction of the SN kinetic energy can be put into low-energy (E<30 MeV) cosmic rays that will eventually escape into the IGM. These subrelativistic cosmic rays could propagate through the Universe and heat the IGM by ~10-100 K by z~15, before more powerful reionization/heating mec...

  13. GALAXIES CORRELATING WITH ULTRA-HIGH ENERGY COSMIC RAYS

    SciTech Connect (OSTI)

    Zaw, Ingyin; Farrar, Glennys R. [Center for Cosmology and Particle Physics and Department of Physics, New York University, New York, NY 10003 (United States); Greene, Jenny E. [Department of Astronomy and Astrophysics, Peyton Hall, Princeton, NJ 08854 (United States)

    2009-05-10

    The Pierre Auger Observatory reported that 20 of the 27 highest energy cosmic rays have arrival directions within 3.{sup 0}2 of a nearby galaxy in the Veron-Cetty and Veron (VCV) Catalog of Quasars and Active Galactic Nuclei (12th ed.), with a 1% probability that this would be due to chance if the cosmic ray directions were isotropic. In this paper, we examine the correlated galaxies to gain insight into the possible ultra-high energy cosmic ray (UHECR) sources. We find that 14 of the 21 correlated VCV galaxies are active galactic nuclei (AGNs) and we determine their bolometric luminosities. The remaining seven are primarily star-forming galaxies. The bolometric luminosities of the correlated AGNs are all greater than 5 x 10{sup 42} erg s{sup -1}. This may explain the absence of UHECRs from the Virgo region in spite of the large number of VCV galaxies in Virgo, since most of the VCV galaxies in the Virgo region are low-luminosity AGNs. Interestingly, the bolometric luminosities of most of the AGNs are significantly lower than that required to satisfy the minimum condition for UHECR acceleration in a continuous jet. If a UHECR-AGN correlation is substantiated with further statistics, our results lend support to the recently proposed 'giant AGN flare' mechanism for UHECR acceleration.

  14. Radio Cherenkov signals from the Moon: neutrinos and cosmic rays

    E-Print Network [OSTI]

    Yu Seon Jeong; Mary Hall Reno; Ina Sarcevic

    2011-08-11

    Neutrino production of radio Cherenkov signals in the Moon is the object of radio telescope observations. Depending on the energy range and detection parameters, the dominant contribution to the neutrino signal may come from interactions of the neutrino on the Moon facing the telescope, rather than neutrinos that have traversed a portion of the Moon. Using the approximate analytic expression of the effective lunar aperture from a recent paper by Gayley, Mutel and Jaeger, we evaluate the background from cosmic ray interactions in the lunar regolith. We also consider the modifications to the effective lunar aperture from generic non-standard model neutrino interactions. A background to neutrino signals are radio Cherenkov signals from cosmic ray interactions. For cosmogenic neutrino fluxes, neutrino signals will be difficult to observe because of low neutrino flux at the high energy end and large cosmic ray background in the lower energy range considered here. We show that lunar radio detection of neutrino interactions is best suited to constrain or measure neutrinos from astrophysical sources and probe non-standard neutrino-nucleon interactions such as microscopic black hole production.

  15. Cosmic-ray diffusive reacceleration: a critical look

    E-Print Network [OSTI]

    Drury, Luke O'C

    2015-01-01

    Cosmic-ray scattering on magnetic turbulence leads to spatial diffusive propagation; if the scattering medium is moving, this will inevitably also cause changes in the momentum of the particles, so-called diffusive reacceleration. This can be described as diffusion in momentum space. Diffusive reacceleration has often been invoked to explain the peak observed in secondary-to-primary ratios at a few GeV, in particular Boron-to-Carbon. This avoids the necessity to postulate an ad-hoc break in the spatial diffusive coefficient, and has become almost a standard in modelling cosmic-ray spectra. However, at the levels invoked, the process implies a significant input of energy from the interstellar medium into cosmic rays, so that in such models interstellar space competes with the usual accelerators like supernova remnants. The questions arise: is reacceleration really occurring at the high level required to explain secondary-to-primary ratios? and are the energy requirements physically plausible? We address this i...

  16. Deducing the Source of Ultrahigh Energy Cosmic Rays

    E-Print Network [OSTI]

    Glennys R. Farrar; Tsvi Piran

    2000-11-02

    The apparent lack of suitable astrophysical sources for cosmic rays with E > 10^{19.7} eV (UHECRs) is the "GZK Paradox". We argue that whatever mechanism produces them must also account for events down to ~10^{18.7} eV, including their isotropy and spectral smoothness. This rules out galactic sources, distributed sources such as topological defects, and Gamma Ray Bursts (GRBs). We are lead to identify the powerful radio galaxy Cen A, at 3.4 Mpc, as the probable source of most UHECRs observed at Earth today, and to estimate the extragalactic magnetic field to be ~0.3 microG.

  17. IS THE GALACTIC COSMIC-RAY SPECTRUM CONSTANT IN TIME?

    SciTech Connect (OSTI)

    Eichler, David; Kumar, Rahul; Pohl, Martin E-mail: rahuliitk@gmail.com

    2013-06-01

    The hypothesis is considered that the present, local Galactic cosmic-ray spectrum is, due to source intermittency, softer than average over time and over the Galaxy. Measurements of muogenic nuclides underground could provide an independent measurement of the time-averaged spectrum. Source intermittency could also account for the surprising low anisotropy reported by the IceCube Collaboration. Predictions for Galactic emission of ultrahigh-energy (UHE) quanta, such as UHE gamma rays and neutrinos, might be higher or lower than previously estimated.

  18. Cosmic rays through the Higgs portal

    E-Print Network [OSTI]

    Rainer Dick; Robert B. Mann; Kai E. Wunderle

    2008-07-16

    We consider electroweak singlet dark matter with a mass comparable to the Higgs mass. The singlet is assumed to couple to standard matter through a perturbative coupling to the Higgs particle. The annihilation of a singlet with a mass comparable to the Higgs mass is dominated by proximity to the W, Z and Higgs peaks in the annihilation cross section. We find that the continuous photon spectrum from annihilation of a perturbatively coupled singlet in the galactic halo can reach a level of several per mil of the EGRET diffuse gamma ray flux.

  19. Cosmic Rays, Gamma-Rays, & Neutrinos in the Starburst Nuclei of Arp 220

    E-Print Network [OSTI]

    Yoast-Hull, Tova M; Zweibel, Ellen G

    2015-01-01

    The cores of Arp 220, the closest ultra-luminous infrared starburst galaxy, provide an opportunity to study interactions of cosmic rays under extreme conditions. In this paper, we model the populations of cosmic rays produced by supernovae in the central molecular zones of both starburst nuclei. We find that ~65 - 100% of cosmic rays are absorbed in these regions due to their huge molecular gas contents, and thus, the nuclei of Arp 220 nearly complete proton calorimeters. As the cosmic ray protons collide with the interstellar medium, they produce secondary electrons that are also contained within the system and radiate synchrotron emission. Using results from chi-squared tests between the model and the observed radio spectral energy distribution, we predict the emergent gamma-ray and high-energy neutrino spectra and find the magnetic field to be at milligauss levels. Because of the extremely intense far-infrared radiation fields, the gamma-ray spectrum steepens significantly at TeV energies due to gamma-gamm...

  20. Diffuse Synchrotron Emission from Galactic Cosmic Ray Electrons

    E-Print Network [OSTI]

    Di Bernardo, Giuseppe; Evoli, Carmelo; Gaggero, Daniele

    2015-01-01

    Synchrotron diffuse radiation (SDR) emission is one of the major Galactic components, in the 100 MHz up to 100 GHz frequency range. Its spectrum and sky map provide valuable measure of the galactic cosmic ray electrons (GCRE) in the relevant energy range, as well as of the strength and structure of the Galactic magnetic fields (GMF), both regular and random ones. This emission is an astrophysical sky foreground for the study of the Cosmic Microwave Background (CMB), and the extragalactic microwave measurements, and it needs to be modelled as better as possible. In this regard, in order to get an accurate description of the SDR in the Galaxy, we use - for the first time in this context - 3-dimensional GCRE models obtained by running the DRAGON code. This allows us to account for a realistic spiral arm pattern of the source distribution, demanded to get a self-consistent treatment of all relevant energy losses influencing the final synchrotron spectrum.

  1. Composition of Primary Cosmic-Ray Nuclei at High Energies

    E-Print Network [OSTI]

    M. Ave; P. J. Boyle; F. Gahbauer; C. Hoppner; J. R. Horandel; M. Ichimura; D. Muller; A. Romero-Wolf

    2008-01-03

    The TRACER instrument (``Transition Radiation Array for Cosmic Energetic Radiation'') has been developed for direct measurements of the heavier primary cosmic-ray nuclei at high energies. The instrument had a successful long-duration balloon flight in Antarctica in 2003. The detector system and measurement process are described, details of the data analysis are discussed, and the individual energy spectra of the elements O, Ne, Mg, Si, S, Ar, Ca, and Fe (nuclear charge Z=8 to 26) are presented. The large geometric factor of TRACER and the use of a transition radiation detector make it possible to determine the spectra up to energies in excess of 10$^{14}$ eV per particle. A power-law fit to the individual energy spectra above 20 GeV per amu exhibits nearly the same spectral index ($\\sim$ 2.65 $\\pm$ 0.05) for all elements, without noticeable dependence on the elemental charge Z.

  2. (In)Feasability of Studying Ultra-High-Energy Cosmic Rays with Smartphones

    E-Print Network [OSTI]

    Unger, Michael

    2015-01-01

    We estimate the effective area available for cosmic-ray detection with a network of smartphones under optimistic conditions. To measure cosmic-ray air showers with a minimally-adequate precision and a detection area similar to existing ground-based detectors, the fraction of participating users needs to unrealistically large. We conclude that the prospects of cosmic-ray research using smartphones are very limited.

  3. The Pierre Auger Observatory II: Studies of Cosmic Ray Composition and Hadronic Interaction models

    E-Print Network [OSTI]

    The Pierre Auger Collaboration; P. Abreu; M. Aglietta; E. J. Ahn; I. F. M. Albuquerque; D. Allard; I. Allekotte; J. Allen; P. Allison; J. Alvarez Castillo; J. Alvarez-Muńiz; M. Ambrosio; A. Aminaei; L. Anchordoqui; S. Andringa; T. Anti?i?; A. Anzalone; C. Aramo; E. Arganda; F. Arqueros; H. Asorey; P. Assis; J. Aublin; M. Ave; M. Avenier; G. Avila; T. Bäcker; M. Balzer; K. B. Barber; A. F. Barbosa; R. Bardenet; S. L. C. Barroso; B. Baughman; J. Bäuml; J. J. Beatty; B. R. Becker; K. H. Becker; A. Bellétoile; J. A. Bellido; S. BenZvi; C. Berat; X. Bertou; P. L. Biermann; P. Billoir; F. Blanco; M. Blanco; C. Bleve; H. Blümer; M. Bohá?ová; D. Boncioli; C. Bonifazi; R. Bonino; N. Borodai; J. Brack; P. Brogueira; W. C. Brown; R. Bruijn; P. Buchholz; A. Bueno; R. E. Burton; K. S. Caballero-Mora; L. Caramete; R. Caruso; A. Castellina; O. Catalano; G. Cataldi; L. Cazon; R. Cester; J. Chauvin; S. H. Cheng; A. Chiavassa; J. A. Chinellato; A. Chou; J. Chudoba; R. W. Clay; M. R. Coluccia; R. Conceiçăo; F. Contreras; H. Cook; M. J. Cooper; J. Coppens; A. Cordier; U. Cotti; S. Coutu; C. E. Covault; A. Creusot; A. Criss; J. Cronin; A. Curutiu; S. Dagoret-Campagne; R. Dallier; S. Dasso; K. Daumiller; B. R. Dawson; R. M. de Almeida; M. De Domenico; C. De Donato; S. J. de Jong; G. De La Vega; W. J. M. de Mello Junior; J. R. T. de Mello Neto; I. De Mitri; V. de Souza; K. D. de Vries; G. Decerprit; L. del Peral; O. Deligny; H. Dembinski; N. Dhital; C. Di Giulio; J. C. Diaz; M. L. Díaz Castro; P. N. Diep; C. Dobrigkeit; W. Docters; J. C. D'Olivo; P. N. Dong; A. Dorofeev; J. C. dos Anjos; M. T. Dova; D. D'Urso; I. Dutan; J. Ebr; R. Engel; M. Erdmann; C. O. Escobar; A. Etchegoyen; P. Facal San Luis; I. Fajardo Tapia; H. Falcke; G. Farrar; A. C. Fauth; N. Fazzini; A. P. Ferguson; A. Ferrero; B. Fick; A. Filevich; A. Filip?i?; S. Fliescher; C. E. Fracchiolla; E. D. Fraenkel; U. Fröhlich; B. Fuchs; R. Gaior; R. F. Gamarra; S. Gambetta; B. García; D. García Gámez; D. Garcia-Pinto; A. Gascon; H. Gemmeke; K. Gesterling; P. L. Ghia; U. Giaccari; M. Giller; H. Glass; M. S. Gold; G. Golup; F. Gomez Albarracin; M. Gómez Berisso; P. Gonçalves; D. Gonzalez; J. G. Gonzalez; B. Gookin; D. Góra; A. Gorgi; P. Gouffon; S. R. Gozzini; E. Grashorn; S. Grebe; N. Griffith; M. Grigat; A. F. Grillo; Y. Guardincerri; F. Guarino; G. P. Guedes; A. Guzman; J. D. Hague; P. Hansen; D. Harari; S. Harmsma; J. L. Harton; A. Haungs; T. Hebbeker; D. Heck; A. E. Herve; C. Hojvat; N. Hollon; V. C. Holmes; P. Homola; J. R. Hörandel; A. Horneffer; M. Hrabovský; T. Huege; A. Insolia; F. Ionita; A. Italiano; C. Jarne; S. Jiraskova; M. Josebachuili; K. Kadija; K. -H. Kampert; P. Karhan; P. Kasper; B. Kégl; B. Keilhauer; A. Keivani; J. L. Kelley; E. Kemp; R. M. Kieckhafer; H. O. Klages; M. Kleifges; J. Kleinfeller; J. Knapp; D. -H. Koang; K. Kotera; N. Krohm; O. Krömer; D. Kruppke-Hansen; F. Kuehn; D. Kuempel; J. K. Kulbartz; N. Kunka; G. La Rosa; C. Lachaud; P. Lautridou; M. S. A. B. Leăo; D. Lebrun; P. Lebrun; M. A. Leigui de Oliveira; A. Lemiere; A. Letessier-Selvon; I. Lhenry-Yvon; K. Link; R. López; A. Lopez Agüera; K. Louedec; J. Lozano Bahilo; A. Lucero; M. Ludwig; H. Lyberis; M. C. Maccarone; C. Macolino; S. Maldera; D. Mandat; P. Mantsch; A. G. Mariazzi; J. Marin; V. Marin; I. C. Maris; H. R. Marquez Falcon; G. Marsella; D. Martello; L. Martin; H. Martinez; O. Martínez Bravo; H. J. Mathes; J. Matthews; J. A. J. Matthews; G. Matthiae; D. Maurizio; P. O. Mazur; G. Medina-Tanco; M. Melissas; D. Melo; E. Menichetti; A. Menshikov; P. Mertsch; C. Meurer; S. Mi?anovi?; M. I. Micheletti; W. Miller; L. Miramonti; S. Mollerach; M. Monasor; D. Monnier Ragaigne; F. Montanet; B. Morales; C. Morello; E. Moreno; J. C. Moreno; C. Morris; M. Mostafá; C. A. Moura; S. Mueller; M. A. Muller; G. Müller; M. Münchmeyer; R. Mussa; G. Navarra; J. L. Navarro; S. Navas; P. Necesal; L. Nellen; A. Nelles; J. Neuser; P. T. Nhung; L. Niemietz; N. Nierstenhoefer; D. Nitz; D. Nosek; L. Nožka; M. Nyklicek; J. Oehlschläger; A. Olinto; V. M. Olmos-Gilbaja; M. Ortiz; N. Pacheco; D. Pakk Selmi-Dei; M. Palatka; J. Pallotta; N. Palmieri; G. Parente; E. Parizot; A. Parra; R. D. Parsons; S. Pastor; T. Paul; M. Pech; J. P?kala; R. Pelayo; I. M. Pepe; L. Perrone; R. Pesce; E. Petermann; S. Petrera; P. Petrinca; A. Petrolini; Y. Petrov; J. Petrovic; C. Pfendner; N. Phan; R. Piegaia; T. Pierog; P. Pieroni; M. Pimenta; V. Pirronello; M. Platino; V. H. Ponce; M. Pontz; P. Privitera; M. Prouza; E. J. Quel; S. Querchfeld; J. Rautenberg; O. Ravel; D. Ravignani; B. Revenu; J. Ridky; S. Riggi; M. Risse; P. Ristori; H. Rivera; V. Rizi; J. Roberts; C. Robledo; W. Rodrigues de Carvalho; G. Rodriguez; J. Rodriguez Martino; J. Rodriguez Rojo; I. Rodriguez-Cabo; M. D. Rodríguez-Frías; G. Ros; J. Rosado

    2011-07-24

    Studies of the composition of the highest energy cosmic rays with the Pierre Auger Observatory, including examination of hadronic physics effects on the structure of extensive air showers.

  4. Investigation of the Galactic Magnetic Field with Ultra-High Energy Cosmic Rays

    E-Print Network [OSTI]

    Erdmann, Martin; Urban, Martin

    2015-01-01

    We present a method to correct for deflections of ultra-high energy cosmic rays in the galactic magnetic field. We perform these corrections by simulating the expected arrival directions of protons using a parameterization of the field derived from Faraday rotation and synchrotron emission measurements. To evaluate the method we introduce a simulated astrophysical scenario and two observables designed for testing cosmic ray deflections. We show that protons can be identified by taking advantage of the galactic magnetic field pattern. Consequently, cosmic ray deflection in the galactic field can be verified experimentally. The method also enables searches for directional correlations of cosmic rays with source candidates.

  5. HAWC Contributions to the 34th International Cosmic Ray Conference (ICRC2015)

    E-Print Network [OSTI]

    Abeysekara, A U; Alvarez, C; Álvarez, J D; Arceo, R; Arteaga-Velázquez, J C; Solares, H A Ayala; Barber, A S; Baughman, B M; Bautista-Elivar, N; Gonzalez, J Becerra; Becerril, A; Belmont, E; BenZvi, S Y; Berley, D; Bernal, A; Braun, J; Caballero-Mora, K S; Capistrán, T; Carramińana, A; Castillo, M; Cotti, U; Cotzomi, J; de León, S Coutińo; de la Fuente, E; De León, C; DeYoung, T; Hernandez, R Diaz; Diaz-Cruz, L; Díaz-Vélez, J C; Dingus, B L; DuVernois, M A; Ellsworth, R W; Engel, K; Enriquez-Rivera, O; Fick, B; Fiorino, D W; Flores, J L; Fraija, N; Garcia-Torales, G; Garfias, F; González, M M; Goodman, J A; Gussert, M; Hampel-Arias, Z; Hansen, P; Harding, J Patrick; Hernandez, S; Hui, C M; Hüntemeyer, P; Imran, A; Iriarte, A; Karn, P; Kieda, D; Kunde, G J; Lara, A; Lauer, R J; Lee, W H; Lennarz, D; Vargas, H León; Linnemann, J T; Proper, M Longo; Raya, G Luis; Luna-García, R; Malone, K; Marinelli, A; Marinelli, S S; Martinez, H; Martinez, O; Martínez-Castro, J; Matthews, J A J; McEnery, J; Miranda-Romagnoli, P; Moreno, E; Mostafá, M; Nellen, L; Newbold, M; Nisa, M Un; Noriega-Papaqui, R; Oceguera-Becerra, T; Patricelli, B; Pelayo, R; Pérez-Pérez, E G; Pretz, J; Ren, Z; Rho, C D; Rivičre, C; Rosa-González, D; Ryan, J; Salazar, H; Greus, F Salesa; Sandoval, A; Schneider, M; Sinnis, G; Smith, A J; Smith, A W; Woodle, K Sparks; Springer, R W; Taboada, I; Tibolla, O; Toale, P A; Tollefson, K; Torres, I; Ukwatta, T N; Villaseńor, L; Weisgarber, T; Westerhoff, S; Wisher, I G; Wood, J; Yapici, T; Yodh, G B; Younk, P W; Zepeda, A; Zhou, H

    2015-01-01

    List of proceedings from the HAWC Collaboration presented at the 34th International Cosmic Ray Conference, 30 July - 6 August 2015, The Hague, The Netherlands.

  6. CTA Contributions to the 34th International Cosmic Ray Conference (ICRC2015)

    E-Print Network [OSTI]

    :,; Abeysekara, U; Abril, Ó; Acero, F; Acharya, B S; Actis, M; Agnetta, G; Aguilar, J A; Aharonian, F; Akhperjanian, A; Albert, A; Alcubierre, M; Alfaro, R; Aliu, E; Allafort, A J; Allan, D; Allekotte, I; Aloisio, R; Amans, J -P; Amato, E; Ambrogi, L; Ambrosi, G; Ambrosio, M; Anderson, J; Anduze, M; Angüner, E O; Antolini, E; Antonelli, L A; Antonucci, M; Antonuccio, V; Antoranz, P; Aramo, C; Aravantinos, A; Argan, A; Armstrong, T; Arnaldi, H; Arnold, L; Arrabito, L; Arrieta, M; Asano, K; Asorey, H G; Aune, T; Singh, C B; Babic, A; Backes, M; Bais, A; Bajtlik, S; Balazs, C; Balbo, M; Balis, D; Balkowski, C; Ballester, O; Ballet, J; Balzer, A; Bamba, A; Bandiera, R; Barber, A; Barbier, C; Barceló, M; Barnacka, A; de Almeida, U Barres; Barrio, J A; Basso, S; Bastieri, D; Bauer, C; Baushev, A; Becciani, U; Becherini, Y; Tjus, J Becker; Beckmann, V; Bednarek, W; Benbow, W; Ventura, D Benedico; Berdugo, J; Berge, D; Bernardini, E; Bernhard, S; Bernlöhr, K; Bertucci, B; Besel, M -A; Bhatt, N; Bhattacharjee, P; Bhattachryya, S; Biasuzzi, B; Bicknell, G; Bigongiari, C; Biland, A; Billotta, S; Bilnik, W; Biondo, B; Bird, T; Birsin, E; Bissaldi, E; Biteau, J; Bitossi, M; Bigas, O Blanch; Blasi, P; Boehm, C; Bogacz, L; Bogdan, M; Bohacova, M; Boisson, C; Gargallo, J Boix; Bolmont, J; Bonanno, G; Bonardi, A; Bonifacio, P; Bonnoli, G; Borkowski, J; Bose, R; Bosnjak, Z; Bottani, A; Böttcher, M; Bousquet, J -J; Boutonnet, C; Bouyjou, F; Braiding, C; Brandt, L; Brau-Nogué, S; Bregeon, J; Bretz, T; Briggs, M; Brigida, M; Bringmann, T; Brisken, W; Britto, R; Brocato, E; Brook, P; Brown, A M; Brun, P; Brun, P; Brunetti, G; Brunetti, L; Bruno, P; Bryan, M; Buanes, T; Bucciantini, N; Buchholtz, G; Buckley, J; Bugaev, V; Bühler, R; Bulgarelli, A; Bulik, T; Burton, M; Burtovoi, A; Busetto, G; Buson, S; Buss, J; Byrum, K; Cameron, R; Camprecios, J; Canelli, F; Canestrari, R; Cantu, S; Capalbi, M; Capasso, M; Capobianco, G; Caraveo, P; Cardenzana, J; Carius, S; Carlile, C; Carmona, E; Carosi, A; Carosi, R; Carr, J; Carroll, M; Carter, J; Carton, P -H; Caruso, R; Casandjian, J -M; Casanova, S; Cascone, E; Casiraghi, M; Castellina, A; Catalano, O; Catalanotti, S; Cavazzani, S; Cazaux, S; Cefalŕ, M; Cerchiara, P; Cereda, M; Cerruti, M; Chabanne, E; Chadwick, P; Champion, C; Chaty, S; Chaves, R; Cheimets, P; Chen, A; Chen, X; Chernyakova, M; Chiappetti, L; Chikawa, M; Chinn, D; Chitnis, V R; Cho, N; Christov, A; Chudoba, J; Cie?lar, M; Cillis, A; Ciocci, M A; Clay, R; Cohen-Tanugi, J; Colafrancesco, S; Colin, P; Colombo, E; Colome, J; Colonges, S; Compin, M; Conforti, V; Connaughton, V; Connell, S; Conrad, J; Contreras, J L; Coppi, P; Corbel, S; Coridian, J; Corona, P; Corti, D; Cortina, J; Cossio, L; Costa, A; Costantini, H; Cotter, G; Courty, B; Covino, S; Covone, G; Crimi, G; Criswell, S J; Crocker, R; Croston, J; Cusumano, G; Da Vela, P; Dale, Ř; D'Ammando, F; Dang, D; Daniel, M; Davids, I; Dawson, B; Dazzi, F; Costa, B de Aguiar; De Angelis, A; Cardoso, R F de Araujo; De Caprio, V; De Cesare, G; De Franco, A; De Frondat, F; Pino, E M de Gouveia Dal; de la Calle, I; De La Vega, G A; Lopez, R de los Reyes; De Lotto, B; De Luca, A; Neto, J R T de Mello; de Naurois, M; Wilhelmi, E de Ońa; De Palma, F; Filho, L V de Souza; Decock, G; Deil, C; Del Santo, M; Delagnes, E; Deleglise, G; Delgado, C; della Volpe, D; Deloye, P; Depaola, G; Detournay, M; Dettlaff, A; Di Girolamo, T; Di Giulio, C; Di Paola, A; Di Pierro, F; Di Sciascio, G; Díaz, C; Dick, J; Dickinson, H; Diebold, S; Diez, V; Digel, S; Dipold, J; Disset, G; Distefano, A; Djannati-Ataď, A; Doert, M; Dohmke, M; Domainko, W; Dominik, N; Prester, D Dominis; Donat, A; Donnarumma, I; Dorner, D; Doro, M; Dournaux, J -L; Doyle, K; Drake, G; Dravins, D; Drury, L; Dubus, G; Dumas, D; Dumm, J; Durand, D; D'Urso, D; Dwarkadas, V; Dyks, J; Dyrda, M; Ebr, J; Echaniz, J C; Edy, E; Egberts, K; Eger, P; Einecke, S; Eisch, J; Eisenkolb, F; Eleftheriadis, C; Elsässer, D; Emmanoulopoulos, D; Engelbrecht, C; Engelhaupt, D; Ernenwein, J -P; Errando, M; Etchegoyen, A; Evans, P; Fairbairn, M; Falcone, A; Fantinel, D; Farakos, K; Farnier, C; Farrell, E; Farrell, S; Fasola, G; Fegan, S; Feinstein, F; Ferenc, D; Fernandez, A; Fernandez-Alonso, M; Ferreira, O; Fesquet, M; Fetfatzis, P; Fiasson, A; Filip?i?, A; Filipovic, M; Fink, D; Finley, C; Finley, J P; Finoguenov, A; Fioretti, V; Fiorini, M; Curcoll, R Firpo; Fleischhack, H; Flores, H; Florin, D; Föhr, C; Fokitis, E; Font, L; Fontaine, G; Fontes, B; Forest, F; Fornasa, M; Förster, A; Fortin, P; Fortson, L; Fouque, N; Franckowiak, A; Franco, F J; Frankowski, A; Frega, N; Albuquerque, I Freire Mota; Coromina, L Freixas; Fresnillo, L; Fruck, C; Fuessling, M; Fugazza, D; Fujita, Y; Fukami, S; Fukazawa, Y; Fukuda, T; Fukui, Y; Funk, S; Gäbele, W; Gabici, S; Gadola, A; Galante, N; Gall, D D; Gallant, Y

    2015-01-01

    List of contributions from the CTA Consortium presented at the 34th International Cosmic Ray Conference, 30 July - 6 August 2015, The Hague, The Netherlands.

  7. The Pierre Auger Observatory: Contributions to the 34th International Cosmic Ray Conference (ICRC 2015)

    E-Print Network [OSTI]

    Aab, A; Aglietta, M; Ahn, E J; Samarai, I Al; Albuquerque, I F M; Allekotte, I; Allison, P; Almela, A; Castillo, J Alvarez; Alvarez-Muńiz, J; Batista, R Alves; Ambrosio, M; Aminaei, A; Anastasi, G A; Anchordoqui, L; Andringa, S; Aramo, C; Arqueros, F; Arsene, N; Asorey, H; Assis, P; Aublin, J; Avila, G; Awal, N; Badescu, A M; Baus, C; Beatty, J J; Becker, K H; Bellido, J A; Berat, C; Bertaina, M E; Bertou, X; Biermann, P L; Billoir, P; Blaess, S G; Blanco, A; Blanco, M; Blazek, J; Bleve, C; Blümer, H; Bohá?ová, M; Boncioli, D; Bonifazi, C; Borodai, N; Brack, J; Brancus, I; Bretz, T; Bridgeman, A; Brogueira, P; Buchholz, P; Bueno, A; Buitink, S; Buscemi, M; Caballero-Mora, K S; Caccianiga, B; Caccianiga, L; Candusso, M; Caramete, L; Caruso, R; Castellina, A; Cataldi, G; Cazon, L; Cester, R; Chavez, A G; Chiavassa, A; Chinellato, J A; Chudoba, J; Cilmo, M; Clay, R W; Cocciolo, G; Colalillo, R; Coleman, A; Collica, L; Coluccia, M R; Conceiçăo, R; Contreras, F; Cooper, M J; Cordier, A; Coutu, S; Covault, C E; Cronin, J; Dallier, R; Daniel, B; Dasso, S; Daumiller, K; Dawson, B R; de Almeida, R M; de Jong, S J; De Mauro, G; Neto, J R T de Mello; De Mitri, I; de Oliveira, J; de Souza, V; del Peral, L; Deligny, O; Dhital, N; Di Giulio, C; Di Matteo, A; Diaz, J C; Castro, M L Díaz; Diogo, F; Dobrigkeit, C; Docters, W; D'Olivo, J C; Dorofeev, A; Hasankiadeh, Q Dorosti; Anjos, R C dos; Dova, M T; Ebr, J; Engel, R; Erdmann, M; Erfani, M; Escobar, C O; Espadanal, J; Etchegoyen, A; Falcke, H; Fang, K; Farrar, G; Fauth, A C; Fazzini, N; Ferguson, A P; Fick, B; Figueira, J M; Filevich, A; Filip?i?, A; Fratu, O; Freire, M M; Fujii, T; García, B; García-Gámez, D; Garcia-Pinto, D; Gate, F; Gemmeke, H; Gherghel-Lascu, A; Ghia, P L; Giaccari, U; Giammarchi, M; Giller, M; G?as, D; Glaser, C; Glass, H; Golup, G; Berisso, M Gómez; Vitale, P F Gómez; González, N; Gookin, B; Gordon, J; Gorgi, A; Gorham, P; Gouffon, P; Griffith, N; Grillo, A F; Grubb, T D; Guarino, F; Guedes, G P; Hampel, M R; Hansen, P; Harari, D; Harrison, T A; Hartmann, S; Harton, J L; Haungs, A; Hebbeker, T; Heck, D; Heimann, P; Hérve, A E; Hill, G C; Hojvat, C; Hollon, N; Holt, E; Homola, P; Hörandel, J R; Horvath, P; Hrabovský, M; Huber, D; Huege, T; Insolia, A; Isar, P G; Jandt, I; Jansen, S; Jarne, C; Johnsen, J A; Josebachuili, M; Kääpä, A; Kambeitz, O; Kampert, K H; Kasper, P; Katkov, I; Keilhauer, B; Kemp, E; Kieckhafer, R M; Klages, H O; Kleifges, M; Kleinfeller, J; Krause, R; Krohm, N; Kuempel, D; Mezek, G Kukec; Kunka, N; Awad, A W Kuotb; LaHurd, D; Latronico, L; Lauer, R; Lauscher, M; Lautridou, P; Coz, S Le; Lebrun, D; Lebrun, P; de Oliveira, M A Leigui; Letessier-Selvon, A; Lhenry-Yvon, I; Link, K; Lopes, L; López, R; Casado, A López; Louedec, K; Lucero, A; Malacari, M; Mallamaci, M; Maller, J; Mandat, D; Mantsch, P; Mariazzi, A G; Marin, V; Mari?, I C; Marsella, G; Martello, D; Martinez, H; Bravo, O Martínez; Martraire, D; Meza, J J Masías; Mathes, H J; Mathys, S; Matthews, J; Matthews, J A J; Matthiae, G; Maurizio, D; Mayotte, E; Mazur, P O; Medina, C; Medina-Tanco, G; Meissner, R; Mello, V B B; Melo, D; Menshikov, A; Messina, S; Micheletti, M I; Middendorf, L; Minaya, I A; Miramonti, L; Mitrica, B; Molina-Bueno, L; Mollerach, S; Montanet, F; Morello, C; Mostafá, M; Moura, C A; Müller, G; Muller, M A; Müller, S; Navas, S; Necesal, P; Nellen, L; Nelles, A; Neuser, J; Nguyen, P H; Niculescu-Oglinzanu, M; Niechciol, M; Niemietz, L; Niggemann, T; Nitz, D; Nosek, D; Novotny, V; Nožka, L; Núńez, L A; Ochilo, L; Oikonomou, F; Olinto, A; Pacheco, N; Selmi-Dei, D Pakk; Palatka, M; Pallotta, J; Papenbreer, P; Parente, G; Parra, A; Paul, T; Pech, M; P?kala, J; Pelayo, R; Pepe, I M; Perrone, L; Petermann, E; Peters, C; Petrera, S; Petrov, Y; Phuntsok, J; Piegaia, R; Pierog, T; Pieroni, P; Pimenta, M; Pirronello, V; Platino, M; Plum, M; Porcelli, A; Porowski, C; Prado, R R; Privitera, P; Prouza, M; Quel, E J; Querchfeld, S; Quinn, S; Rautenberg, J; Ravel, O; Ravignani, D; Reinert, D; Revenu, B; Ridky, J; Risse, M; Ristori, P; Rizi, V; de Carvalho, W Rodrigues; Rojo, J Rodriguez; Rodríguez-Frías, M D; Rogozin, D; Rosado, J; Roth, M; Roulet, E; Rovero, A C; Saffi, S J; Saftoiu, A; Salamida, F; Salazar, H; Saleh, A; Greus, F Salesa; Salina, G; Gomez, J D Sanabria; Sánchez, F; Sanchez-Lucas, P; Santos, E M; Santos, E; Sarazin, F; Sarkar, B; Sarmento, R; Sarmiento-Cano, C; Sato, R; Scarso, C; Schauer, M; Scherini, V; Schieler, H; Schmidt, D; Scholten, O; Schoorlemmer, H; Schovánek, P; Schröder, F G; Schulz, A; Schulz, J; Schumacher, J; Sciutto, S J; Segreto, A; Settimo, M; Shadkam, A; Shellard, R C; Sigl, G; Sima, O; ?mia?kowski, A; Šmída, R; Snow, G R; Sommers, P; Sonntag, S; Sorokin, J; Squartini, R; Srivastava, Y N; Stanca, D; Stani?, S; Stapleton, J; Stasielak, J

    2015-01-01

    Contributions of the Pierre Auger Collaboration to the 34th International Cosmic Ray Conference, 30 July - 6 August 2015, The Hague, The Netherlands

  8. GZK Photons as Ultra High Energy Cosmic Rays

    E-Print Network [OSTI]

    Graciela B. Gelmini; Oleg E. Kalashev; Dmitry V. Semikoz

    2007-11-01

    We calculate the flux of "GZK-photons", namely the flux of Ultra High Energy Cosmic Rays (UHECR) consisting of photons produced by extragalactic nucleons through the resonant photoproduction of pions, the so called GZK effect. We We calculate the flux of "GZK-photons", namely the flux of Ultra High Energy Cosmic Rays (UHECR) consisting of photons produced by extragalactic nucleons through the resonant photoproduction of pions, the so called GZK effect. We show that, for primary nucleons, the GZK photon fraction of the total UHECR flux is between $10^{-4}$ and $10^{-2}$ above $10^{19}$ eV and up to the order of 0.1 above $10^{20}$ eV. The GZK photon flux depends on the assumed UHECR spectrum, slope of the nucleon flux at the source, distribution of sources and intervening backgrounds. Detection of this photon flux would open the way for UHECR gamma-ray astronomy. Detection of a larger photon flux would imply the emission of photons at the source or new physics. We compare the photon fractions expected for GZK photons and the minimal predicted by Top-Down models. We find that the photon fraction above $10^{19}$ eV is a crucial test for Top-Down models.

  9. Los Alamos, Toshiba probing Fukushima with cosmic rays

    ScienceCinema (OSTI)

    Morris, Christopher

    2014-06-25

    Los Alamos National Laboratory has announced an impending partnership with Toshiba Corporation to use a Los Alamos technique called muon tomography to safely peer inside the cores of the Fukushima Daiichi reactors and create high-resolution images of the damaged nuclear material inside without ever breaching the cores themselves. The initiative could reduce the time required to clean up the disabled complex by at least a decade and greatly reduce radiation exposure to personnel working at the plant. Muon radiography (also called cosmic-ray radiography) uses secondary particles generated when cosmic rays collide with upper regions of Earth's atmosphere to create images of the objects that the particles, called muons, penetrate. The process is analogous to an X-ray image, except muons are produced naturally and do not damage the materials they contact. Muon radiography has been used before in imaginative applications such as mapping the interior of the Great Pyramid at Giza, but Los Alamos's muon tomography technique represents a vast improvement over earlier technology.

  10. Los Alamos, Toshiba probing Fukushima with cosmic rays

    SciTech Connect (OSTI)

    Morris, Christopher

    2014-06-16

    Los Alamos National Laboratory has announced an impending partnership with Toshiba Corporation to use a Los Alamos technique called muon tomography to safely peer inside the cores of the Fukushima Daiichi reactors and create high-resolution images of the damaged nuclear material inside without ever breaching the cores themselves. The initiative could reduce the time required to clean up the disabled complex by at least a decade and greatly reduce radiation exposure to personnel working at the plant. Muon radiography (also called cosmic-ray radiography) uses secondary particles generated when cosmic rays collide with upper regions of Earth's atmosphere to create images of the objects that the particles, called muons, penetrate. The process is analogous to an X-ray image, except muons are produced naturally and do not damage the materials they contact. Muon radiography has been used before in imaginative applications such as mapping the interior of the Great Pyramid at Giza, but Los Alamos's muon tomography technique represents a vast improvement over earlier technology.

  11. Cosmic Ray production of Beryllium and Boron at high redshift

    E-Print Network [OSTI]

    Emmanuel Rollinde; David Maurin; Elisabeth Vangioni; Keith A. Olive; Susumu Inoue

    2007-07-13

    Recently, new observations of Li6 in Pop II stars of the galactic halo have shown a surprisingly high abundance of this isotope, about a thousand times higher than its predicted primordial value. In previous papers, a cosmological model for the cosmic ray-induced production of this isotope in the IGM has been developed to explain the observed abundance at low metallicity. In this paper, given this constraint on the Li6, we calculate the non-thermal evolution with redshift of D, Be, and B in the IGM. In addition to cosmological cosmic ray interactions in the IGM, we include additional processes driven by SN explosions: neutrino spallation and a low energy component in the structures ejected by outflows to the IGM. We take into account CNO CRs impinging on the intergalactic gas. Although subdominant in the galactic disk, this process is shown to produce the bulk of Be and B in the IGM, due to the differential metal enrichment between structures (where CRs originate) and the IGM. We also consider the resulting extragalactic gamma-ray background which we find to be well below existing data. The computation is performed in the framework of hierarchical structure formation considering several star formation histories including Pop III stars. We find that D production is negligible and that a potentially detectable Be and B plateau is produced by these processes at the time of the formation of the Galaxy (z ~ 3).

  12. Neutrino and cosmic-ray emission from multiple internal shocks in gamma-ray bursts

    E-Print Network [OSTI]

    Mauricio Bustamante; Philipp Baerwald; Kohta Murase; Walter Winter

    2015-10-14

    Gamma-ray bursts are short-lived, luminous explosions at cosmological distances, thought to originate from relativistic jets launched at the deaths of massive stars. They are among the prime candidates to produce the observed cosmic rays at the highest energies. Recent neutrino data have, however, started to constrain this possibility in the simplest models with only one emission zone. In the classical theory of gamma-ray bursts, it is expected that particles are accelerated at mildly relativistic shocks generated by the collisions of material ejected from a central engine. We consider neutrino and cosmic-ray emission from multiple emission regions since these internal collisions must occur at very different radii, from below the photosphere all the way out to the circumburst medium, as a consequence of the efficient dissipation of kinetic energy. We demonstrate that the different messengers originate from different collision radii, which means that multi-messenger observations open windows for revealing the evolving GRB outflows.

  13. Constraints on particle dark matter from cosmic-ray antiprotons

    E-Print Network [OSTI]

    N. Fornengo; L. Maccione; A. Vittino

    2015-01-30

    Cosmic-ray antiprotons represent an important channel for dark matter indirect-detection studies. Current measurements of the antiproton flux at the top of the atmosphere and theoretical determinations of the secondary antiproton production in the Galaxy are in good agreement, with no manifest deviation which could point to an exotic contribution in this channel. Therefore, antiprotons can be used as a powerful tool for constraining particle dark matter properties. By using the spectrum of PAMELA data from 50 MV to 180 GV in rigidity, we derive bounds on the dark matter annihilation cross section (or decay rate, for decaying dark matter) for the whole spectrum of dark matter annihilation (decay) channels and under different hypotheses of cosmic-rays transport in the Galaxy and in the heliosphere. For typical models of galactic propagation, the constraints are significantly strong, setting a lower bound on the dark matter mass of a "thermal" relic at about 50-90 GeV for hadronic annihilation channels. These bounds are enhanced to about 150 GeV on the dark matter mass, when large cosmic-rays confinement volumes in the Galaxy are considered, and are reduced to 4-5 GeV for annihilation to light quarks (no bound for heavy-quark production) when the confinement volume is small. Bounds for dark matter lighter than few tens of GeV are due to the low energy part of the PAMELA spectrum, an energy region where solar modulation is relevant: to this aim, we have implemented a detailed solution of the transport equation in the heliosphere, which allowed us not only to extend bounds to light dark matter, but also to determine the uncertainty on the constraints arising from solar modulation modeling. Finally, we estimate the impact of soon-to-come AMS-02 data on the antiproton constraints.

  14. Exotic massive hadrons and ultrahigh energy cosmic rays

    SciTech Connect (OSTI)

    Albuquerque, I.F. [Department of Astronomy and Astrophysics, Enrico Fermi Institute, The University of Chicago, Chicago, Illinois 60637 (United States)] [Department of Astronomy and Astrophysics, Enrico Fermi Institute, The University of Chicago, Chicago, Illinois 60637 (United States); Farrar, G.R. [Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08855 (United States)] [Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08855 (United States); Kolb, E.W. [NASA/Fermilab Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)] [NASA/Fermilab Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); [Department of Astronomy and Astrophysics, Enrico Fermi Institute, The University of Chicago, Chicago, Illinois 60637 (United States)

    1999-01-01

    We investigate the proposal that primary cosmic rays of energy above the Greisen-Zatsepin-Kuzmin cutoff are exotic massive strongly interacting particles (uhecrons). We study the properties of air showers produced by uhecrons and find that masses in excess of about 50 GeV are inconsistent with the highest energy event observed. We also estimate that with sufficient statistics a uhecron of mass as low as 10 GeV may be distinguished from a proton. {copyright} {ital 1998} {ital The American Physical Society}

  15. Statistical Tools for Analyzing the Cosmic Ray Energy Spectrum

    E-Print Network [OSTI]

    J. D. Hague; B. R. Becker; M. S. Gold; J. A. J. Matthews

    2008-08-20

    In this paper un-binned statistical tools for analyzing the cosmic ray energy spectrum are developed and illustrated with a simulated data set. The methods are designed to extract accurate and precise model parameter estimators in the presence of statistical and systematic energy errors. Two robust methods are used to test for the presence of flux suppression at the highest energies: the Tail-Power statistic and a likelihood ratio test. Both tests give evidence of flux suppression in the simulated data. The tools presented can be generalized for use on any astrophysical data set where the power-law assumption is relevant and can be used to aid observational design.

  16. A simple technique for gamma ray and cosmic ray spectroscopy using plastic scintillator

    E-Print Network [OSTI]

    Akhilesh P. Nandan; Sharmili Rudra; Himangshu Neog; S. Biswas; S. Mahapatra; B. Mohanty; P. K. Samal

    2015-04-10

    A new and simple technique has been developed using plastic scintillator detectors for gamma ray and cosmic ray spectroscopy without single channel analyzer (SCA) or multichannel analyzer (MCA). In these experiments only a leading edge discriminator (LED) and NIM scalers have been used. Energy calibration of gamma spectra in plastic scintillators has been done using Co$^{60}$ and Cs$^{137}$ sources. The details experimental technique, analysis procedure and experimental results has been presented in this article.

  17. A Lookup Table to Compute High Energy Cosmic Ray Effects on Terrestrial Atmospheric Chemistry

    E-Print Network [OSTI]

    Atri, Dimitra

    2009-04-27

    A variety of events such as gamma-ray bursts and supernovae may expose the Earth to an increased flux of high-energy cosmic rays, with potentially important effects on the biosphere. Existing atmospheric chemistry software does not have...

  18. On the Origin of Highest Energy Cosmic Rays

    E-Print Network [OSTI]

    G. Sigl; D. N. Schramm; P. Bhattacharjee

    1994-03-17

    In this paper we show that the conventional diffusive shock acceleration mechanism for cosmic rays associated with relativistic astrophysical shocks in active galactic nuclei (AGNs) has severe difficulties to explain the highest energy cosmic ray events. We show that protons above around $2\\times10^{20}\\eV$ could have marginally been produced by this mechanism in an AGN or a rich galaxy cluster not further away than around $100\\Mpc$. However, for the highest energy Fly's Eye and Yakutsk events this is inconsistent with the observed arrival directions. Galactic and intergalactic magnetic fields appear unable to alter the direction of such energetic particles by more than a few degrees. We also discuss some other options for these events associated with relativistic particles including pulsar acceleration of high $Z$ nuclei. At the present stage of knowledge the concept of topological defects left over from the early universe as the source for such events appears to be a promising option. Such sources are discussed and possible tests of this hypothesis are proposed.

  19. A new look at the cosmic ray positron fraction

    E-Print Network [OSTI]

    Boudaud, Mathieu

    2015-01-01

    The positron fraction in cosmic rays was found to be steadily increasing in function of energy, above $\\sim$10 GeV. This behaviour contradicts standard astrophysical mechanisms, in which positrons are secondary particles, produced in the interactions of primary cosmic rays during the propagation in the interstellar medium. The observed anomaly in the positron fraction triggered a lot of excitement, as it could be interpreted as an indirect signature of the presence of dark matter species in the Galaxy. Alternatively, it could be produced by nearby astrophysical sources, such as pulsars. Both hypotheses are probed in this work in light of the latest AMS-02 positron fraction measurements. The transport of primary and secondary positrons in the Galaxy is described using a semi-analytic two-zone model. MicrOMEGAs is used to model the positron flux generated by dark matter species. We provide mass and annihilating cross section that best fit AMS-02 data for each single annihilating channel as well as for combinati...

  20. Pinpointing the knee of cosmic rays with diffuse PeV ?-rays and neutrinos

    SciTech Connect (OSTI)

    Guo, Y. Q.; Hu, H. B.; Yuan, Q.; Tian, Z.; Gao, X. J. [Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049 (China)

    2014-11-01

    The origin of the knee in the cosmic ray spectrum remains to be an unsolved fundamental problem. There are various kinds of models that predict different break positions and the compositions of the knee. In this work, we suggest the use of diffuse ?-rays and neutrinos as probes to test these models. Based on several typical types of composition models, the diffuse ?-ray and neutrino spectra are calculated and show distinctive cutoff behaviors at energies from tens of TeV to multi-PeV. The expected flux will be observable by the newly upgraded Tibet-AS?+MD (muon detector) experiment as well as more sensitive future projects, such as LHAASO and HiSCORE. By comparing the neutrino spectrum with the recent observations by the IceCube experiment, we find that the diffuse neutrinos from interactions between the cosmic rays and the interstellar medium may not be responsible to the majority of the IceCube events. Future measurements of the neutrinos may be able to identify the Galactic diffuse component and shed further light on the problem of the knee of cosmic rays.

  1. Gamma Ray Bursts: recent results and connections to very high energy Cosmic Rays and Neutrinos

    E-Print Network [OSTI]

    Péter Mészáros; Katsuaki Asano; Péter Veres

    2012-09-11

    Gamma-ray bursts are the most concentrated explosions in the Universe. They have been detected electromagnetically at energies up to tens of GeV, and it is suspected that they could be active at least up to TeV energies. It is also speculated that they could emit cosmic rays and neutrinos at energies reaching up to the $10^{18}-10^{20}$ eV range. Here we review the recent developments in the photon phenomenology in the light of \\swift and \\fermi satellite observations, as well as recent IceCube upper limits on their neutrino luminosity. We discuss some of the theoretical models developed to explain these observations and their possible contribution to a very high energy cosmic ray and neutrino background.

  2. Measurement of the flux of ultra high energy cosmic rays using data from very inclined air

    E-Print Network [OSTI]

    Hebbeker, Thomas

    Measurement of the flux of ultra high energy cosmic rays using data from very inclined air showers.1.2 Cosmic rays above 100 TeV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.2 Extensive air-model of the hadronic cascade . . . . . . . . . . . . . . . . . . . . . . . . 16 3.3 Very inclined air showers

  3. Air fluorescence relevant for cosmic-ray detection--Review of pioneering measurements

    E-Print Network [OSTI]

    Hörandel, Jörg R.

    Air fluorescence relevant for cosmic-ray detection--Review of pioneering measurements Fernando Keywords: Fluorescence yield Air showers a b s t r a c t Cosmic rays with energies exceeding 1017 eV are frequently registered by measurements of the fluorescence light emitted by extensive air showers. The main

  4. On the relationship between cosmic rays, solar activity and powerful earthquakes

    E-Print Network [OSTI]

    Mikhail Kovalyov; Selena Kovalyov

    2015-02-10

    In this paper we analyze the correlation of cosmic rays intensity to increases in seismic activity. We also show that high-magnitude earthquakes appear in group. As a prequel, we discuss in \\S1 naive visualization of the solar-cosmic ray interplay.

  5. Energy spectra of elemental groups of cosmic rays: Update on the KASCADE unfolding analysis

    E-Print Network [OSTI]

    Hörandel, Jörg R.

    Energy spectra of elemental groups of cosmic rays: Update on the KASCADE unfolding analysis W model. In this update of the analysis we apply the unfolding method with a different low energy 2008 Accepted 26 November 2008 Available online 13 December 2008 Keywords: Cosmic ray energy spectrum

  6. Neutron production by cosmic-ray muons at shallow depth J. Busenitz,1

    E-Print Network [OSTI]

    Piepke, Andreas G.

    Neutron production by cosmic-ray muons at shallow depth F. Boehm,3 J. Busenitz,1 B. Cook,3 G Received 23 June 2000; published 12 October 2000 The yield of neutrons produced by cosmic ray muons of one and two neutron captures was determined. Modeling the neutron capture efficiency allowed us

  7. 28th International Cosmic Ray Conference 3901 Effective Energy of Neutron Monitors

    E-Print Network [OSTI]

    Usoskin, Ilya G.

    in the course of the solar cycle. Here we present a new concept of the effective energy of cosmic rays measured above this effective energy, irrespective of the phase of the solar cycle. The new concept to the flux of cosmic rays with energy above this effective energy, irrespectively of the phase of solar cycle

  8. Roadmap for Ultra-High Energy Cosmic Ray Physics and Astronomy (whitepaper for Snowmass 2013)

    E-Print Network [OSTI]

    Luis A. Anchordoqui; Glennys R. Farrar; John F. Krizmanic; Jim Matthews; John W. Mitchell; Dave Nitz; Angela V. Olinto; Thomas C. Paul; Pierre Sokolsky; Gordon B. Thomson; Thomas J. Weiler

    2013-07-29

    We summarize the remarkable recent progress in ultra-high energy cosmic ray physics and astronomy enabled by the current generation of cosmic ray observatories. We discuss the primary objectives for future measurements and describe the plans for near-term enhancements of existing experiments as well as the next generation of observatories.

  9. Roadmap for Ultra-High Energy Cosmic Ray Physics and Astronomy (whitepaper for Snowmass 2013)

    E-Print Network [OSTI]

    Anchordoqui, Luis A; Krizmanic, John F; Matthews, Jim; Mitchell, John W; Olinto, Angela V; Paul, Thomas C; Sokolsky, Pierre; Thomson, Gordon B; Weiler, Thomas J

    2013-01-01

    We summarize the remarkable recent progress in ultra-high energy cosmic ray physics and astronomy enabled by the current generation of cosmic ray observatories. We discuss the primary objectives for future measurements and describe the plans for near-term enhancements of existing experiments as well as the next generation of observatories.

  10. Calculation of the cosmic ray induced ionization for the region P Makrantoni1

    E-Print Network [OSTI]

    Usoskin, Ilya G.

    Calculation of the cosmic ray induced ionization for the region of Athens P Makrantoni1 , H(T,) is the differential energy spectrum of galactic cosmic rays in the Earth's vicinity (given in units of [cm2 sec sr (GeV/nuc)]-1 ). Integration is performed above Tc,i , which is the kinetic energy of a particle of i-th type

  11. Possible association of ultra-high-energy cosmic-ray events with strong gamma-ray bursts

    E-Print Network [OSTI]

    Mordehai Milgrom; Vladimir Usov

    1995-05-03

    We point out that each of the error boxes of the two highest-energy cosmic-ray shower events known, overlaps with that of a strong gamma-ray burst (GRB). The GRBs precede the cosmic rays by 5.5, and 11 months respectively. In one case the strongest known cosmic ray is paired with the strongest gamma-ray burst in the BATSE catalogue. The probability of this to have occurred by chance seems rather small. Without building on post-factum statistics, we think the above is remarkable enough to suggest that the cosmic ray and gamma-ray burst were produced by the same outburst. A time delay (and a small positional disparity) is expected, since the trajectory of a charged cosmic-ray particle is wriggled by intervening magnetic fields. We estimate that the Galaxy's field alone may produce a delay of the order observed. We discuss some of the implications that follow if such an association is confirmed. For example, the upper limit on the distance to the cosmic-ray source, combined with a much-better-determined position of the gamma-ray burst source, narrows greatly the volume in which to look for an optical counterpart. There is also useful information in the time delay regarding, e.g., intergalactic magnetic fields.

  12. Nuclear enhancement of the photon yield in cosmic ray interactions

    SciTech Connect (OSTI)

    Kachelriess, Michael [Institutt for fysikk, NTNU, NO-7491 Trondheim (Norway); Moskalenko, Igor V.; Ostapchenko, Sergey S. [Hansen Experimental Physics Laboratory and Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305 (United States)

    2014-07-10

    The concept of the nuclear enhancement factor has been used since the beginning of ?-ray astronomy. It provides a simple and convenient way to account for the contribution of nuclei (A > 1) in cosmic rays (CRs) and in the interstellar medium (ISM) to the diffuse ?-ray emission. An accurate treatment of the dominant emission process, such as hadronic interactions of CRs with the ISM, enables one to study CR acceleration processes and CR propagation in the ISM, and provides a reliable background model for searches of new phenomena. The Fermi Large Area Telescope launched in 2008 provides excellent quality data in a wide energy range 30 MeV-1 TeV where the diffuse emission accounts for the majority of photons. Exploiting its data to the fullest requires a new study of the processes of ?-ray production in hadronic interactions. In this paper we point out that several commonly used studies of the nuclear enhancement factor fail to account for the spectrally averaged energy loss fraction which ensures that the energy fraction transferred to photons is averaged properly with the spectra of CR species. We present a new calculation of the spectrally averaged energy loss fraction and the nuclear enhancement factor using the QGSJET-II-04 and EPOS-LHC interaction models.

  13. Study of the Shadow of the Moon in Very High Energy Cosmic Rays with the Milagrito Water Cherenkov Detector

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    Study of the Shadow of the Moon in Very High Energy Cosmic Rays with the Milagrito Water Cherenkov of the Moon in Very High Energy Cosmic Rays with the Milagrito Water Cherenkov Detector by Morgan O of California at Riverside 2001 #12; Study of the Shadow of the Moon in Very High Energy Cosmic Rays

  14. Primary Cosmic Ray Proton Flux Measured by AMS-02

    E-Print Network [OSTI]

    Consolandi, C

    2014-01-01

    The Alpha Magnetic Spectrometer (AMS-02) is a high energy particle detector designed to study origin and nature of cosmic rays up to a few TV from space. It was installed on the International Space Station (ISS) on May 19, 2011. During the first two years of operation AMS-02 performed precise measurements of the proton flux. In the low rigidity range, from 1 GV to 20 GV, the proton flux was daily measured with a statistical error less than 1%. In the same rigidity range a gradual decrease due to Solar modulation effect and transit variations due to Solar Flares and Coronal Mass Ejection were also observed. In the rigidity range from 20 GV up to 100 GV instead, AMS-02 data show no drastic variation and the results are consistent with other experiments. Above 100 GV, AMS-02 proton flux exhibits a single power low behavior with no fine structures nor brakes.

  15. Characterising encapsulated nuclear waste using cosmic-ray muon tomography

    E-Print Network [OSTI]

    Clarkson, Anthony; Hoek, Matthias; Ireland, David G; Johnstone, John R; Kaiser, Ralf; Keri, Tibor; Lumsden, Scott; Mahon, David F; McKinnon, Bryan; Murray, Morgan; Nutbeam-Tuffs, Siân; Shearer, Craig; Yang, Guangliang; Zimmerman, Colin

    2014-01-01

    Tomographic imaging techniques using the Coulomb scattering of cosmic-ray muons have been shown previously to successfully identify and characterise low- and high-Z materials within an air matrix using a prototype scintillating-fibre tracker system. Those studies were performed as the first in a series to assess the feasibility of this technology and image reconstruction techniques in characterising the potential high-Z contents of legacy nuclear waste containers for the UK Nuclear Industry. The present work continues the feasibility study and presents the first images reconstructed from experimental data collected using this small-scale prototype system of low- and high-Z materials encapsulated within a concrete-filled stainless-steel container. Clear discrimination is observed between the thick steel casing, the concrete matrix and the sample materials assayed. These reconstructed objects are presented and discussed in detail alongside the implications for future industrial scenarios.

  16. On Solar System and Cosmic Rays Nucleosynthesis and Spallation Processes

    E-Print Network [OSTI]

    Stepan G. Mashnik

    2000-08-24

    A brief survey of nuclide abundances in the solar-system and in cosmic rays and of the believed mechanisms of their synthesis is given. The role of spallation processes in nucleosynthesis is discussed. A short review of recent measurements, compilations, calculations, and evaluations of spallation cross sections relevant to nuclear astrophysics is given as well. It is shown that in some past astrophysical simulations, old experimental nuclear data and theoretical cross sections that are in poor agreement with recent measurements and calculations were used. New astrophysical simulations using recently measured and reliably calculated nuclear cross sections, further researches in obtaining better cross sections, and production of evaluated spallation cross sections libraries for astrophysics are suggested.

  17. The cosmic ray positron excess and neutralino dark matter

    E-Print Network [OSTI]

    Edward A. Baltz; Joakim Edsjo; Katherine Freese; Paolo Gondolo

    2001-12-14

    Using a new instrument, the HEAT collaboration has confirmed the excess of cosmic ray positrons that they first detected in 1994. We explore the possibility that this excess is due to the annihilation of neutralino dark matter in the galactic halo. We confirm that neutralino annihilation can produce enough positrons to make up the measured excess only if there is an additional enhancement to the signal. We quantify the `boost factor' that is required in the signal for various models in the Minimal Supersymmetric Standard Model parameter space, and study the dependence on various parameters. We find models with a boost factor greater than 30. Such an enhancement in the signal could arise if we live in a clumpy halo. We discuss what part of supersymmetric parameter space is favored (in that it gives the largest positron signal), and the consequences for other direct and indirect searches of supersymmetric dark matter.

  18. Galactic cosmic ray induced radiation dose on terrestrial exoplanets

    E-Print Network [OSTI]

    Atri, Dimitra; Griessmeier, Jean-Mathias

    2013-01-01

    This past decade has seen tremendous advancements in the study of extrasolar planets. Observations are now made with increasing sophistication from both ground and space based instruments, and exoplanets are characterized with increasing precision. There is a class of particularly interesting exoplanets, falling in the habitable zone, which is defined as the area around a star where the planet is capable of supporting liquid water on its surface. Theoretical calculations also suggest that close-in exoplanets are more likely to have weaker planetary magnetic fields, especially in case of super earths. Such exoplanets are subjected to a high flux of Galactic Cosmic Rays (GCRs) due to their weak magnetic moments. GCRs are energetic particles of astrophysical origin, which strike the planetary atmosphere and produce secondary particles, including muons, which are highly penetrating. Some of these particles reach the planetary surface and contribute to the radiation dose. Along with the magnetic field, another fac...

  19. Characterising encapsulated nuclear waste using cosmic-ray muon tomography

    E-Print Network [OSTI]

    Anthony Clarkson; David J. Hamilton; Matthias Hoek; David G. Ireland; John R. Johnstone; Ralf Kaiser; Tibor Keri; Scott Lumsden; David F. Mahon; Bryan McKinnon; Morgan Murray; Siân Nutbeam-Tuffs; Craig Shearer; Guangliang Yang; Colin Zimmerman

    2014-10-27

    Tomographic imaging techniques using the Coulomb scattering of cosmic-ray muons have been shown previously to successfully identify and characterise low- and high-Z materials within an air matrix using a prototype scintillating-fibre tracker system. Those studies were performed as the first in a series to assess the feasibility of this technology and image reconstruction techniques in characterising the potential high-Z contents of legacy nuclear waste containers for the UK Nuclear Industry. The present work continues the feasibility study and presents the first images reconstructed from experimental data collected using this small-scale prototype system of low- and high-Z materials encapsulated within a concrete-filled stainless-steel container. Clear discrimination is observed between the thick steel casing, the concrete matrix and the sample materials assayed. These reconstructed objects are presented and discussed in detail alongside the implications for future industrial scenarios.

  20. Heavy Cosmic Ray Nuclei from Extragalactic Sources above 'The Ankle'

    E-Print Network [OSTI]

    Tadeusz Wibig; Arnold W. Wolfendale

    2007-12-20

    A very recent observation by the Auger Observatory group claims strong evidence for cosmic rays above 56 EeV being protons from Active Galactic Nuclei. If, as would be expected, the particles above the ankle at about 2 EeV are almost all of extragalactic origin then it follows that the characteristics of the nuclear interactions of such particles would need to be very different from conventional expectation -- a result that follows from the measured positions of 'shower maximum' in the Auger' work. Our own analysis gives a different result, viz that the detected particles are still 'massive' specifically with a mean value of = 2.2 +- 0.8. The need for a dramatic change in the nuclear physics disappears.

  1. Massive galaxy clusters and the origin of Ultra High Energy Cosmic Rays

    E-Print Network [OSTI]

    Elena Pierpaoli; Glennys Farrar

    2005-11-22

    We investigate whether ultra--high energy cosmic rays (UHECR) may be preferentially produced in massive galaxy clusters, by looking for correlations between UHECR directions and those of x-ray clusters. We find an excess-above-random of high energy cosmic rays which correlate with massive galaxy cluster positions. For cosmic rays with energies above 50 EeV the observed correlation is the strongest or angles of 1.2-1.6 degrees where it has a chance probability of about 0.1%. Including lower energy cosmic rays in the sample causes the angle where the most significant correlation is found to increase, as would be expected by virtue of instrumental and magnetic smearing increasing at lower energy. These results suggest that some UHECR are produced in galaxy clusters, or in objects that preferentially populate galaxy clusters.

  2. Modeling high-energy cosmic ray induced terrestrial and atmospheric neutron flux: A lookup table

    E-Print Network [OSTI]

    Overholt, Andrew; Atri, Dimitra

    2013-01-01

    Under current conditions, the cosmic ray spectrum incident on the Earth is dominated by particles with energies solar flares, supernovae and gamma ray bursts produce high energy cosmic rays (HECRs) with drastically higher energies. The Earth is likely episodically exposed to a greatly increased HECR flux from such events, some of which lasting thousands to millions of years. The air showers produced by HECRs ionize the atmosphere and produce harmful secondary particles such as muons and neutrons. Neutrons currently contribute a significant radiation dose at commercial passenger airplane altitude. With higher cosmic ray energies, these effects will be propagated to ground level. This work shows the results of Monte Carlo simulations quantifying the neutron flux due to high energy cosmic rays at various primary energies and altitudes. We provide here lookup tables that can be used to determine neutron fluxes from primaries with total energies 1 GeV - 1 PeV...

  3. The Cosmic Ray Energy Spectrum and Related Measurements with the Pierre Auger Observatory

    SciTech Connect (OSTI)

    Abraham, : J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Ahn, E.J.; Allard, D.; Allekotte, I.; Allen, J.; Alvarez-Muniz, J.; Ambrosio, M.; Anchordoqui, L.

    2009-06-01

    These are presentations to be presented at the 31st International Cosmic Ray Conference, in Lodz, Poland during July 2009. It consists of the following presentations: (1) Measurement of the cosmic ray energy spectrum above 10{sup 18} eV with the Pierre Auger Observatory; (2) The cosmic ray flux observed at zenith angles larger than 60 degrees with the Pierre Auger Observatory; (3) Energy calibration of data recorded with the surface detectors of the Pierre Auger Observatory; (4) Exposure of the Hybrid Detector of The Pierre Auger Observatory; and (5) Energy scale derived from Fluorescence Telescopes using Cherenkov Light and Shower Universality.

  4. On the spectrum of high-energy cosmic rays produced by supernova remnants in the presence of strong cosmic-ray streaming instability and wave dissipation

    E-Print Network [OSTI]

    V. S. Ptuskin; V. N. Zirakashvili

    2004-08-02

    The cosmic-ray streaming instability creates strong magnetohydrodynamic turbulence in the precursor of a SN shock. The level of turbulence determines the maximum energy of cosmic-ray particles accelerated by the diffusive shock acceleration mechanism. The present consideration continues our work Ptuskin & Zirakashvili (2003). It is assumed that the Kolmogorov type nonlinear wave interactions together with the ion-neutral collisions restrict the amplitude of random magnetic field. As a result, the maximum energy of accelerated particles strongly depends on the age of a SNR. The average spectrum of cosmic rays injected in the interstellar medium over the course of adiabatic SNR evolution (the Sedov stage) is approximately $Q(p)p^{2}\\propto p^{-2}$ at energies larger than 10-30 Gev/nucleon and with the maximum particle energy that is close to the knee position in cosmic ray spectrum observed at $\\sim4\\times10^{15}$ eV. At earlier stage of SNR evolution - the ejecta dominated stage described by the Chevalier-Nadyozhin solution, the particles are accelerated to higher energies and have rather steep power-law distribution on momentum. These results suggest that the knee may mark the transition from the ejecta-dominated to the adiabatic evolution of SNR shocks which accelerate cosmic rays.

  5. Earth Planets Space, 62, 333345, 2010 Cosmic ray and solar energetic particle flux in paleomagnetospheres

    E-Print Network [OSTI]

    Steinhoff, Heinz-Jürgen

    Earth Planets Space, 62, 333­345, 2010 Cosmic ray and solar energetic particle flux of the shield prohibiting energetic particles of solar and cosmic origin directly hitting the Earth surface particles. 1. Introduction Planet Earth possesses a global magnetic field since at least 3.2 billion years

  6. Gamma Rays from Clusters and Groups of Galaxies: Cosmic Rays versus Dark Matter

    E-Print Network [OSTI]

    Tesla E. Jeltema; John Kehayias; Stefano Profumo

    2009-05-22

    Clusters of galaxies have not yet been detected at gamma-ray frequencies; however, the recently launched Fermi Gamma-ray Space Telescope, formerly known as GLAST, could provide the first detections in the near future. Clusters are expected to emit gamma rays as a result of (1) a population of high-energy primary and re-accelerated secondary cosmic rays (CR) fueled by structure formation and merger shocks, active galactic nuclei and supernovae, and (2) particle dark matter (DM) annihilation. In this paper, we ask the question of whether the Fermi telescope will be able to discriminate between the two emission processes. We present data-driven predictions for a large X-ray flux limited sample of galaxy clusters and groups. We point out that the gamma ray signals from CR and DM can be comparable. In particular, we find that poor clusters and groups are the systems predicted to have the highest DM to CR emission at gamma-ray energies. Based on detailed Fermi simulations, we study observational handles that might enable us to distinguish the two emission mechanisms, including the gamma-ray spectra, the spatial distribution of the signal and the associated multi-wavelength emissions. We also propose optimal hardness ratios, which will help to understand the nature of the gamma-ray emission. Our study indicates that gamma rays from DM annihilation with a high particle mass can be distinguished from a CR spectrum even for fairly faint sources. Discriminating a CR spectrum from a light DM particle will be instead much more difficult, and will require long observations and/or a bright source. While the gamma-ray emission from our simulated clusters is extended, determining the spatial distribution with Fermi will be a challenging task requiring an optimal control of the backgrounds.

  7. THE INTERPLANETARY NETWORK SUPPLEMENT TO THE BATSE CATALOGS OF UNTRIGGERED COSMIC GAMMA-RAY BURSTS

    E-Print Network [OSTI]

    California at Berkeley, University of

    THE INTERPLANETARY NETWORK SUPPLEMENT TO THE BATSE CATALOGS OF UNTRIGGERED COSMIC GAMMA-RAY BURSTS gamma-ray bursts (GRBs) observed as untriggered events by the Burst and Transient Source Experiment to detect BATSE un- triggered bursts. Subject headinggs: catalogs -- gamma rays: bursts Online material

  8. The Interplanetary Network Supplement to the BATSE 5B Catalog of Cosmic Gamma-Ray Bursts

    E-Print Network [OSTI]

    California at Berkeley, University of

    The Interplanetary Network Supplement to the BATSE 5B Catalog of Cosmic Gamma-Ray Bursts K. Hurley Interplanetary Network (IPN) localization information for 343 gamma-ray bursts observed by the Burst Gamma-Ray Observatory (CGRO) mission, obtained by analyzing the arrival times of these bursts

  9. Detecting particles with cell phones: the Distributed Electronic Cosmic-ray Observatory

    E-Print Network [OSTI]

    Vandenbroucke, Justin; Karn, Peter; Meehan, Matthew; Plewa, Matthew; Ruggles, Tyler; Schultz, David; Peacock, Jeffrey; Simons, Ariel Levi

    2015-01-01

    In 2014 the number of active cell phones worldwide for the first time surpassed the number of humans. Cell phone camera quality and onboard processing power (both CPU and GPU) continue to improve rapidly. In addition to their primary purpose of detecting photons, camera image sensors on cell phones and other ubiquitous devices such as tablets, laptops and digital cameras can detect ionizing radiation produced by cosmic rays and radioactive decays. While cosmic rays have long been understood and characterized as a nuisance in astronomical cameras, they can also be identified as a signal in idle camera image sensors. We present the Distributed Electronic Cosmic-ray Observatory (DECO), a platform for outreach and education as well as for citizen science. Consisting of an app and associated database and web site, DECO harnesses the power of distributed camera image sensors for cosmic-ray detection.

  10. Detecting particles with cell phones: the Distributed Electronic Cosmic-ray Observatory

    E-Print Network [OSTI]

    Justin Vandenbroucke; Silvia Bravo; Peter Karn; Matthew Meehan; Matthew Plewa; Tyler Ruggles; David Schultz; Jeffrey Peacock; Ariel Levi Simons

    2015-10-26

    In 2014 the number of active cell phones worldwide for the first time surpassed the number of humans. Cell phone camera quality and onboard processing power (both CPU and GPU) continue to improve rapidly. In addition to their primary purpose of detecting photons, camera image sensors on cell phones and other ubiquitous devices such as tablets, laptops and digital cameras can detect ionizing radiation produced by cosmic rays and radioactive decays. While cosmic rays have long been understood and characterized as a nuisance in astronomical cameras, they can also be identified as a signal in idle camera image sensors. We present the Distributed Electronic Cosmic-ray Observatory (DECO), a platform for outreach and education as well as for citizen science. Consisting of an app and associated database and web site, DECO harnesses the power of distributed camera image sensors for cosmic-ray detection.

  11. Relative Composition and Energy Spectra of Light Nuclei in Cosmic Rays: Results from AMS-01

    E-Print Network [OSTI]

    Becker, R.

    Measurement of the chemical and isotopic composition of cosmic rays is essential for the precise understanding of their propagation in the galaxy. While the model parameters are mainly determined using the B/C ratio, the ...

  12. Search for microquasar features in cosmic ray spectra with AMS-01

    E-Print Network [OSTI]

    Monreal, Benjamin, 1977-

    2004-01-01

    Accreting x-ray binaries are sometimes observed to emit compact, relativistic jets of cool plasma; these objects are called "microquasars". It is possible that these jets are responsible for a large flux of galactic cosmic ...

  13. CTA contributions to the 33rd International Cosmic Ray Conference (ICRC2013)

    E-Print Network [OSTI]

    The CTA Consortium; :; O. Abril; B. S. Acharya; M. Actis; G. Agnetta; J. A. Aguilar; F. Aharonian; M. Ajello; A. Akhperjanian; M. Alcubierre; J. Aleksic; R. Alfaro; E. Aliu; A. J. Allafort; D. Allan; I. Allekotte; R. Aloisio; E. Amato; G. Ambrosi; M. Ambrosio; J. Anderson; E. O. Angüner; L. A. Antonelli; V. Antonuccio; M. Antonucci; P. Antoranz; A. Aravantinos; A. Argan; T. Arlen; C. Aramo; T. Armstrong; H. Arnaldi; L. Arrabito; K. Asano; T. Ashton; H. G. Asorey; T. Aune; Y. Awane; H. Baba; A. Babic; N. Baby; J. Bähr; A. Bais; C. Baixeras; S. Bajtlik; M. Balbo; D. Balis; C. Balkowski; J. Ballet; A. Bamba; R. Bandiera; A. Barber; C. Barbier; M. Barceló; A. Barnacka; J. Barnstedt; U. Barres de Almeida; J. A. Barrio; A. Basili; S. Basso; D. Bastieri; C. Bauer; A. Baushev; U. Becciani; J. Becerra; J. Becerra; Y. Becherini; K. C. Bechtol; J. Becker Tjus; V. Beckmann; W. Bednarek; B. Behera; M. Belluso; W. Benbow; J. Berdugo; D. Berge; K. Berger; F. Bernard; T. Bernardino; K. Bernlöhr; B. Bertucci; N. Bhat; S. Bhattacharyya; B. Biasuzzi; C. Bigongiari; A. Biland; S. Billotta; T. Bird; E. Birsin; E. Bissaldi; J. Biteau; M. Bitossi; S. Blake; O. Blanch Bigas; P. Blasi; A. Bobkov; V. Boccone; M. Böttcher; L. Bogacz; J. Bogart; M. Bogdan; C. Boisson; J. Boix Gargallo; J. Bolmont; G. Bonanno; A. Bonardi; T. Bonev; P. Bonifacio; G. Bonnoli; P. Bordas; A. Borgland; J. Borkowski; R. Bose; O. Botner; A. Bottani; L. Bouchet; M. Bourgeat; C. Boutonnet; A. Bouvier; S. Brau-Nogué; I. Braun; T. Bretz; M. Briggs; M. Brigida; T. Bringmann; R. Britto; P. Brook; P. Brun; L. Brunetti; P. Bruno; N. Bucciantini; T. Buanes; J. Buckley; R. Bühler; V. Bugaev; A. Bulgarelli; T. Bulik; G. Busetto; S. Buson; K. Byrum; M. Cailles; R. Cameron; J. Camprecios; R. Canestrari; S. Cantu; M. Capalbi; P. Caraveo; E. Carmona; A. Carosi; R. Carosi; J. Carr; J. Carter; P. -H. Carton; R. Caruso; S. Casanova; E. Cascone; M. Casiraghi; A. Castellina; O. Catalano; S. Cavazzani; S. Cazaux; P. Cerchiara; M. Cerruti; E. Chabanne; P. Chadwick; C. Champion; R. Chaves; P. Cheimets; A. Chen; J. Chiang; L. Chiappetti; M. Chikawa; V. R. Chitnis; F. Chollet; A. Christof; J. Chudoba; M. Cie?lar; A. Cillis; M. Cilmo; A. Codino; J. Cohen-Tanugi; S. Colafrancesco; P. Colin; J. Colome; S. Colonges; M. Compin; P. Conconi; V. Conforti; V. Connaughton; J. Conrad; J. L. Contreras; P. Coppi; J. Coridian; P. Corona; D. Corti; J. Cortina; L. Cossio; A. Costa; H. Costantini; G. Cotter; B. Courty; S. Couturier; S. Covino; G. Crimi; S. J. Criswell; J. Croston; G. Cusumano; M. Dafonseca; O. Dale; M. Daniel; J. Darling; I. Davids; F. Dazzi; A. de Angelis; V. De Caprio; F. De Frondat; E. M. de Gouveia Dal Pino; I. de la Calle; G. A. De La Vega; R. de los Reyes Lopez; B. de Lotto; A. De Luca; M. de Naurois; Y. de Oliveira; E. de Ońa Wilhelmi; F. de Palma; V. de Souza; G. Decerprit; G. Decock; C. Deil; E. Delagnes; G. Deleglise; C. Delgado; D. della Volpe; P. Demange; G. Depaola; A. Dettlaff; T. Di Girolamo; C. Di Giulio; A. Di Paola; F. Di Pierro; G. di Sciascio; C. Díaz; J. Dick; R. Dickherber; H. Dickinson; V. Diez-Blanco; S. Digel; D. Dimitrov; G. Disset; A. Djannati-Ataď; M. Doert; M. Dohmke; W. Domainko; D. Dominis Prester; A. Donat; D. Dorner; M. Doro; J. -L. Dournaux; G. Drake; D. Dravins; L. Drury; F. Dubois; R. Dubois; G. Dubus; C. Dufour; D. Dumas; J. Dumm; D. Durand; V. Dwarkadas; J. Dyks; M. Dyrda; J. Ebr; E. Edy; K. Egberts; P. Eger; S. Einecke; C. Eleftheriadis; S. Elles; D. Emmanoulopoulos; D. Engelhaupt; R. Enomoto; J. -P. Ernenwein; M. Errando; A. Etchegoyen; P. A. Evans; A. Falcone; A. Faltenbacher; D. Fantinel; K. Farakos; C. Farnier; E. Farrell; G. Fasola; B. W. Favill; E. Fede; S. Federici; S. Fegan; F. Feinstein; D. Ferenc; P. Ferrando; M. Fesquet; P. Fetfatzis; A. Fiasson; E. Fillin-Martino; D. Fink; C. Finley; J. P. Finley; M. Fiorini; R. Firpo Curcoll; E. Flandrini; H. Fleischhack; H. Flores; D. Florin; W. Focke; C. Föhr; E. Fokitis; L. Font; G. Fontaine; M. Fornasa; A. Förster; L. Fortson; N. Fouque; A. Franckowiak; F. J. Franco; A. Frankowski; C. Fransson; G. W. Fraser; R. Frei; L. Fresnillo; C. Fruck; D. Fugazza; Y. Fujita; Y. Fukazawa; Y. Fukui; S. Funk; W. Gäbele; S. Gabici; R. Gabriele; A. Gadola; N. Galante; D. Gall; Y. Gallant; J. Gámez-García; M. Garczarczyk; B. García; R. Garcia López; D. Gardiol; F. Gargano; D. Garrido; L. Garrido; D. Gascon; M. Gaug; J. Gaweda; L. Gebremedhin; N. Geffroy; L. Gerard; A. Ghedina; M. Ghigo; P. Ghislain; E. Giannakaki; F. Gianotti; S. Giarrusso; G. Giavitto; B. Giebels; N. Giglietto; V. Gika; M. Giomi; P. Giommi; F. Giordano; N. Girard; E. Giro; A. Giuliani; T. Glanzman; J. -F. Glicenstein; N. Godinovic; V. Golev; M. Gomez Berisso; J. Gómez-Ortega; M. M. Gonzalez; A. González; F. González; A. González Muńoz; K. S. Gothe; T. Grabarczyk; M. Gougerot; R. Graciani

    2013-07-29

    Compilation of CTA contributions to the proceedings of the 33rd International Cosmic Ray Conference (ICRC2013), which took place in 2-9 July, 2013, in Rio de Janeiro, Brazil

  14. Dissipation of Magnetohydrodynamic Waves on Energetic Particles: Impact on Interstellar Turbulence and Cosmic Ray

    E-Print Network [OSTI]

    Strong, Andrew W.

    acceleration of cosmic rays by MHD waves is accompanied by the damping of the waves, since the wave energy zirak@mpimail.mpi-hd.mpg.de 1 Also Institute for Physical Science and Technology, University of Maryland

  15. Neutrino, Neutron, and Cosmic Ray Production in the External Shock Model of Gamma Ray Bursts

    E-Print Network [OSTI]

    Charles D. Dermer

    2002-04-16

    The hypothesis that ultra-high energy (>~ 10^19 eV) cosmic rays (UHECRs) are accelerated by gamma-ray burst (GRB) blast waves is assumed to be correct. Implications of this assumption are then derived for the external shock model of gamma-ray bursts. The evolving synchrotron radiation spectrum in GRB blast waves provides target photons for the photomeson production of neutrinos and neutrons. Decay characteristics and radiative efficiencies of the neutral particles that escape from the blast wave are calculated. The diffuse high-energy GRB neutrino background and the distribution of high-energy GRB neutrino events are calculated for specific parameter sets, and a scaling relation for the photomeson production efficiency in surroundings with different densities is derived. GRBs provide an intense flux of high-energy neutrons, with neutron-production efficiencies exceeding ~ 1% of the total energy release. The radiative characteristics of the neutron beta-decay electrons from the GRB "neutron bomb" are solved in a special case. Galaxies with GRB activity should be surrounded by radiation halos of ~ 100 kpc extent from the outflowing neutrons, consisting of a nonthermal optical/X-ray synchrotron component and a high-energy gamma-ray component from Compton-scattered microwave background radiation. The luminosity of sources of GRBs and relativistic outflows in L* galaxies such as the Milky Way is at the level of ~10^40+-1 ergs/s. This is sufficient to account for UHECR generation by GRBs. We briefly speculate on the possibility that hadronic cosmic rays originate from the subset of supernovae that collapse to form relativistic outflows and GRBs. (abridged)

  16. New Solution of Diffusion-Advection Equation for Cosmic-Ray Transport Using Ultradistributions

    E-Print Network [OSTI]

    M. C. Rocca; A. Plastino; A. R. Plastino; A. L. De Paoli

    2014-12-19

    In this paper we exactly solve the diffusion-advection equation for cosmic-ray transport. With this purpose we use the Theory of Ultradistributions of J. Sebastiao e Silva, to give a general solution for this equation. From this solution, we obtain several approximations as limiting cases of various situations of physical and astrophysical interest. One of them involves Solar cosmic-rays' diffusion.

  17. UHECR ESCAPE MECHANISMS FOR PROTONS AND NEUTRONS FROM GAMMA-RAY BURSTS, AND THE COSMIC-RAY-NEUTRINO CONNECTION

    SciTech Connect (OSTI)

    Baerwald, Philipp; Bustamante, Mauricio; Winter, Walter, E-mail: philipp.baerwald@physik.uni-wuerzburg.de, E-mail: mauricio.bustamante@physik.uni-wuerzburg.de, E-mail: winter@physik.uni-wuerzburg.de [Institut fuer Theoretische Physik und Astrophysik, Universitaet Wuerzburg, D-97074 Wuerzburg (Germany)

    2013-05-10

    The paradigm that gamma-ray burst fireballs are the sources of the ultra-high energy cosmic rays (UHECRs) is being probed by neutrino observations. Very stringent bounds can be obtained from the cosmic-ray (proton)-neutrino connection, assuming that the UHECRs escape as neutrons. In this study, we identify three different regimes as a function of the fireball parameters: the standard ''one neutrino per cosmic ray'' case, the optically thick (to neutron escape) case, and the case where leakage of protons from the boundaries of the shells (direct escape) dominates. In the optically thick regime, the photomeson production is very efficient, and more neutrinos will be emitted per cosmic ray than in the standard case, whereas in the direct escape-dominated regime, more cosmic rays than neutrinos will be emitted. We demonstrate that, for efficient proton acceleration, which is required to describe the observed UHECR spectrum, the standard case only applies to a very narrow region of the fireball parameter space. We illustrate with several observed examples that conclusions on the cosmic-ray-neutrino connection will depend on the actual burst parameters. We also show that the definition of the pion production efficiency currently used by the IceCube collaboration underestimates the neutrino production in the optically thick case. Finally, we point out that the direct escape component leads to a spectral break in the cosmic-ray spectrum emitted from a single source. The resulting ''two-component model'' can be used to even more strongly pronounce the spectral features of the observed UHECR spectrum than the dip model.

  18. A Predictive Analytic Model for the Solar Modulation of Cosmic Rays

    E-Print Network [OSTI]

    Ilias Cholis; Dan Hooper; Tim Linden

    2015-11-04

    An important factor limiting our ability to understand the production and propagation of cosmic rays pertains to the effects of heliospheric forces, commonly known as solar modulation. The solar wind is capable of generating time and charge-dependent effects on the spectrum and intensity of low energy ($\\lsim$ 10 GeV) cosmic rays reaching Earth. Previous analytic treatments of solar modulation have utilized the force-field approximation, in which a simple potential is adopted whose amplitude is selected to best fit the cosmic-ray data taken over a given period of time. Making use of recently available cosmic-ray data from the Voyager 1 spacecraft, along with measurements of the heliospheric magnetic field and solar wind, we construct a time, charge and rigidity-dependent model of solar modulation that can be directly compared to data from a variety of cosmic-ray experiments. We provide a simple analytic formula that can be easily utilized in a variety of applications, allowing us to better predict the effects of solar modulation and reduce the number of free parameters involved in cosmic ray propagation models.

  19. Transitional solar dynamics, cosmic rays and global warming

    E-Print Network [OSTI]

    A. Bershadskii

    2009-04-12

    Solar activity is studied using a cluster analysis of the time-fluctuations of the sunspot number. It is shown that in an Historic period the high activity components of the solar cycles exhibit strong clustering, whereas in a Modern period (last seven solar cycles: 1933-2007) they exhibit a white-noise (non-)clustering behavior. Using this observation it is shown that in the Historic period, emergence of the sunspots in the solar photosphere was strongly dominated by turbulent photospheric convection. In the Modern period, this domination was broken by a new more active dynamics of the inner layers of the convection zone. Then, it is shown that the dramatic change of the sun dynamics at the transitional period (between the Historic and Modern periods, solar cycle 1933-1944yy) had a clear detectable impact on Earth climate. A scenario of a chain of transitions in the solar convective zone is suggested in order to explain the observations, and a forecast for the global warming is suggested on the basis of this scenario. A relation between the recent transitions and solar long-period chaotic dynamics has been found. Contribution of the galactic turbulence (due to galactic cosmic rays) has been discussed. These results are also considered in a content of chaotic climate dynamics at millennial timescales.

  20. Galaxies Correlating with Ultra-high Energy Cosmic Rays

    E-Print Network [OSTI]

    Ingyin Zaw; Glennys R. Farrar; Jenny E. Greene

    2008-06-23

    The Pierre Auger Observatory reports that 20 of the 27 highest energy cosmic rays have arrival directions within 3.2 deg of a nearby galaxy in the Veron-Cetty & Veron Catalog of Quasars and Active Galactic Nuclei (12th Ed.), with ~5 of the correlations expected by chance. In this paper we examine the correlated galaxies to gain insight into the possible UHECR sources. We find that 14 of the 21 correlated VCV galaxies are AGNs and we determine their bolometric luminosities. The remaining 7 are primarily star-forming galaxies. The bolometric luminosities of the correlated AGNs are all greater than 5 x 10^{42} erg/s, which may explain the absence of UHECRs from the Virgo region in spite of the large number of VCV galaxies in Virgo, since most of the VCV galaxies in the Virgo region are low luminosity AGNs. Interestingly, the bolometric luminosities of most of the AGNs are significantly lower than required to satisfy the minimum condition for UHECR acceleration in a continuous jet. If a UHECR-AGN correlation is substantiated with further statistics, our results lend support to the recently proposed ``giant AGN flare" mechanism for UHECR acceleration.

  1. Search for Antimatter with the AMS Cosmic Ray Detector

    SciTech Connect (OSTI)

    Cristinziani, Markus

    2003-03-24

    Antimatter search results of the Alpha Magnetic Spectrometer (AMS) detector are presented. About 10{sup 8} triggers were collected in the 1998 precursor flight onboard space shuttle Discovery. This ten day mission exposed the detector on a 51.7{sup o} orbit at an altitude around 350km. Identification of charged cosmic rays is achieved by multiple energy loss and time-of-flight measurements. Bending inside the 0.15T magnetic volume yields a measurement of the absolute value of the particle's rigidity. The supplemental knowledge of the sense of traversal identifies the sign of the charge. In the rigidity range 1 < R < 140 GV no antinucleus at any rigidity was detected, while 2.86 x 10{sup 6} helium and 1.65 x 10{sup 5} heavy nuclei were precisely measured. Hence, upper limits on the flux ratio {bar Z}/Z are given. Different prior assumptions on the antimatter spectrum are considered and corresponding limits are given.

  2. The renaissance of radio detection of cosmic rays

    E-Print Network [OSTI]

    Huege, Tim

    2013-01-01

    Nearly 50 years ago, the first radio signals from cosmic ray air showers were detected. After many successful studies, however, research ceased not even 10 years later. Only a decade ago, the field was revived with the application of powerful digital signal processing techniques. Since then, the detection technique has matured, and we are now in a phase of transition from small-scale experiments accessing energies below 1018 eV to experiments with a reach for energies beyond 1019 eV. We have demonstrated that air shower radio signals carry information on both the energy and the mass of the primary particle, and current experiments are in the process of quantifying the precision with which this information can be accessed. All of this rests on a solid understanding of the radio emission processes which can be interpreted as a coherent superposition of geomagnetic emission, Askaryan charge-excess radiation, and Cherenkov-like coherence effects arising in the density gradient of the atmosphere. In this article, ...

  3. Drift effects on the galactic cosmic ray modulation

    SciTech Connect (OSTI)

    Laurenza, M.; Storini, M.; Carbone, V.

    2014-02-01

    Cosmic ray (CR) modulation is driven by both solar activity and drift effects in the heliosphere, although their role is only qualitatively understood as it is difficult to connect the CR variations to their sources. In order to address this problem, the Empirical Mode Decomposition technique has been applied to the CR intensity, recorded by three neutron monitors at different rigidities (Climax, Rome, and Huancayo-Haleakala (HH)), the sunspot area, as a proxy for solar activity, the heliospheric magnetic field magnitude, directly related to CR propagation, and the tilt angle (TA) of the heliospheric current sheet (HCS), which characterizes drift effects on CRs. A prominent periodicity at ?six years is detected in all the analyzed CR data sets and it is found to be highly correlated with changes in the HCS inclination at the same timescale. In addition, this variation is found to be responsible for the main features of the CR modulation during periods of low solar activity, such as the flat (peaked) maximum in even (odd) solar cycles. The contribution of the drift effects to the global Galactic CR modulation has been estimated to be between 30% and 35%, depending on the CR particle energy. Nevertheless, the importance of the drift contribution is generally reduced in periods nearing the sunspot maximum. Finally, threshold values of ?40°, ?45°, and >55° have been derived for the TA, critical for the CR modulation at the Climax, Rome, and HH rigidity thresholds, respectively.

  4. Particle injection and cosmic ray acceleration at collisionless parallel shocks

    SciTech Connect (OSTI)

    Quest, K.B.

    1987-01-01

    The structure of collisionless parallel shocks is studied using one-dimensional hybrid simulations, with emphasis on particle injection into the first-order Fermi acceleration process. It is argued that for sufficiently high Mach number shocks, and in the absence of wave turbulence, the fluid firehose marginal stability condition will be exceeded at the interface between the upstream, unshocked, plasma and the heated plasma downstream. As a consequence, nonlinear, low-frequency, electromagnetic waves are generated and act to slow the plasma and provide dissipation for the shock. It is shown that large amplitude waves at the shock ramp scatter a small fraction of the upstream ions back into the upstream medium. These ions, in turn, resonantly generate the electromagnetic waves that are swept back into the shock. As these waves propagate through the shock they are compressed and amplified, allowing them to non-resonantly scatter the bulk of the plasma. Moreover, the compressed waves back-scatter a small fraction of the upstream ions, maintaining the shock structure in a quasi-steady state. The back-scattered ions are accelerated during the wave generation process to 2 to 4 times the ram energy and provide a likely seed population for cosmic rays. 49 refs., 7 figs.

  5. Probing Fukushima with cosmic rays should help speed cleanup...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    to peer inside the damaged reactors at the Fukushima Daiichi complex and get detailed pictures-without ever breaching the containment building. oshiba probing Fukushima with cosmic...

  6. 28th International Cosmic Ray Conference 2269 Preliminary Evidence for TeV Gamma Ray Emission from

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    28th International Cosmic Ray Conference 2269 Preliminary Evidence for TeV Gamma Ray Emission from of view results in a higher sensitivity to the diffuse emission from the galaxy com- pared to previous experiments in the same energy band. Preliminary evidence for TeV gamma emission from the galactic plane using

  7. A new measurement of the cosmic X-ray background

    E-Print Network [OSTI]

    A. Moretti; C. Pagani; G. Cusumano; S. Campana; M. Perri; A. Abbey; M. Ajello; A. P. Beardmore; D. Burrows; G. Chincarini; O. Godet; C. Guidorzi; J. E. Hill; J. Kennea; J. Nousek; J. P. Osborne; G. Tagliaferri

    2008-12-09

    We present a new measurement of the cosmic X-ray background (CXRB) in the 1.5-7 keV energy band, performed by exploiting the Swift X-ray telescope (XRT) data archive. We also present a CXRB spectral model in a wider energy band (1.5-200 keV), obtained by combining these data with the recently published Swift-BAT measurement. From the XRT archive we collect a complete sample of 126 high Galactic latitude gamma-ray burst (GRB) follow-up observations. This provides a total exposure of 7.5 Ms and a sky-coverage of 7 square degrees which represents a serendipitous survey, well suited for a direct measurement of the CXRB in the 1.5-10 keV interval. Our work is based on a complete characterization of the instrumental background and an accurate measurement of the stray-light contamination and vignetting calibration. We find that the CXRB spectrum in the 1.5-7 keV energy band can be equally well fitted by a single power-law with photon index Gamma=1.47+/-0.07 or a single power-law with photon index Gamma=1.41+/-0.06 and an exponential roll-off at 41 keV. The measured flux in the 2-10 keV energy band is 2.18+/-0.13 E-11 erg/(cm2 s deg2) in the 2-10 keV band. Combining Swift-XRT with Swift-BAT (15-200 keV) we find that, in the 1.5-200 keV band, the CXRB spectrum can be well described by two smoothly-joined power laws with the energy break at 29.0+/-0.5 keV corresponding to a nu F_nu peak located at 22.4+/-0.4 keV. Taking advantage of both the Swift high energy instruments (XRT and BAT), we produce an analytical description of the CXRB spectrum over a wide (1.5-200 keV) energy band. This model is marginally consistent with the HEAO1 measurement (~10% higher at energies higher than 20 keV, while it is significantly (30%) higher at low energies (2-10 keV).

  8. Population III Generated Cosmic Rays and the Production of Li6

    E-Print Network [OSTI]

    Emmanuel Rollinde; Elisabeth Vangioni; Keith A. Olive

    2006-05-24

    We calculate the evolution of Li6 generated from cosmic rays produced by an early population of massive stars. The computation is performed in the framework of hierarchical structure formation and is based on cosmic star formation histories constrained to reproduce the observed star formation rate at redshift z \\la 6, the observed chemical abundances in damped Lyman alpha absorbers and in the intergalactic medium, and to allow for an early reionization of the Universe at z\\sim 11 by Pop III stars as indicated by the third year results released by WMAP. We show that the pregalactic production of the Li6 isotope in the IGM via these Pop III stars can account for the Li6 plateau observed in metal poor halo stars without additional over-production of Li7. Our results depend on the efficiency of cosmic rays to propagate out of minihalos and the fraction of supernovae energy deposited in cosmic rays. We also compute the cosmic ray heating of the IGM gas. In general, we find somewhat high temperatures (of order 10^5 K) implying that the cosmic rays production of Li6 may be required to be confined to the so-called warm-hot IGM.

  9. Ultra-High Energy Cosmic Rays and Neutron-Decay Halos from Gamma Ray Bursts

    E-Print Network [OSTI]

    C. D. Dermer

    2001-03-20

    Simple arguments concerning power and acceleration efficiency show that ultra-high energy cosmic rays (UHECRS) with energies >~ 10^{19} eV could originate from GRBs. Neutrons formed through photo-pion production processes in GRB blast waves leave the acceleration site and travel through intergalactic space, where they decay and inject a very energetic proton and electron component into intergalactic space. The neutron-decay protons form a component of the UHECRs, whereas the neutron-decay electrons produce optical/X-ray synchrotron and gamma radiation from Compton-scattered background radiation. A significant fraction of galaxies with GRB activity should be surrounded by neutron-decay halos of characteristic size ~ 100 kpc.

  10. Identification of Light Cosmic-Ray Nuclei with AMS-02

    E-Print Network [OSTI]

    Nicola Tomassetti; Alberto Oliva

    2015-10-30

    AMS-02 is a wide acceptance (0.5 m2 sr) and long duration (up to 20 years) magnetic spectrometer operating onboard the International Space Station since May 2011. Its main scientific objectives are the indirect research of Dark Matter, searches of primitive Anti-Matter and the precise measurement of the Cosmic-Ray (CR) spectra. Among charged CR species, AMS-02 will be able to measure relative abundances and absolute fluxes of CRs nuclei from Hydrogen up to at least Iron (Z = 26) in a kinetic energy range from hundreds MeV to TeV per nucleon. The high statistics measurement of the chemical composition of CRs in this extended energy range will reveal new insights about the CRs life in the Galaxy, from their origin to the propagation in the interstellar medium, giving new constraints to astrophysical models of Galactic CRs. The nucleus absolute charge, Z, is measured several times along the trajectory of the particle inside AMS-02 using different detection techniques: in the 9 planes of the Silicon Tracker, in the 4 layers of scintillator counters of the Time-of-Flight system (TOF), in the Ring Imaging Cherenkov Counter (RICH) as well as in the 20 layers of Transition Radiation Detector (TRD) and in the upper layers of the Electromagnetic Calorimeter (ECAL). The combination of the redundant measurements delivered by the tracking system and by the TOF allows an accurate discrimination between chemical elements. The charge measurements in the detectors on top of AMS, as the Upper plane of the Tracker and in TRD, is used for the identification of the incoming nuclear specie and allows the charge-changing events background estimation. The AMS-02 different charge measurement principles are here briefly explained, and performance of each sub-detector presented. Then the AMS-02 combined charge separation capability as well as the interaction events identification principles are presented.

  11. Lookup tables to compute high energy cosmic ray induced atmospheric ionization and changes in atmospheric chemistry

    E-Print Network [OSTI]

    Dimitra Atri; Adrian L. Melott; Brian C. Thomas

    2010-05-03

    A variety of events such as gamma-ray bursts and supernovae may expose the Earth to an increased flux of high-energy cosmic rays, with potentially important effects on the biosphere. Existing atmospheric chemistry software does not have the capability of incorporating the effects of substantial cosmic ray flux above 10 GeV . An atmospheric code, the NASA-Goddard Space Flight Center two-dimensional (latitude, altitude) time-dependent atmospheric model (NGSFC), is used to study atmospheric chemistry changes. Using CORSIKA, we have created tables that can be used to compute high energy cosmic ray (10 GeV - 1 PeV) induced atmospheric ionization and also, with the use of the NGSFC code, can be used to simulate the resulting atmospheric chemistry changes. We discuss the tables, their uses, weaknesses, and strengths.

  12. Review of the theoretical and experimental status of dark matter identification with cosmic-ray antideuterons

    E-Print Network [OSTI]

    Aramaki, T; Bufalino, S; Dal, L; von Doetinchem, P; Donato, F; Fornengo, N; Fuke, H; Grefe, M; Hailey, C; Hamilton, B; Ibarra, A; Mitchell, J; Mognet, I; Ong, R A; Pereira, R; Perez, K; Putze, A; Raklev, A; Salati, P; Sasaki, M; Tarle, G; Urbano, A; Vittino, A; Wild, S; Xue, W; Yoshimura, K

    2015-01-01

    Recent years have seen increased theoretical and experimental effort towards the first-ever detection of cosmic-ray antideuterons, in particular as an indirect signature of dark matter annihilation or decay. In contrast to indirect dark matter searches using positrons, antiprotons, or gamma-rays, which suffer from relatively high and uncertain astrophysical backgrounds, searches with antideuterons benefit from very suppressed conventional backgrounds, offering a potential breakthrough in unexplored phase space for dark matter. This article is based on the first dedicated cosmic-ray antideuteron workshop, which was held at UCLA in June 2014. It reviews broad classes of dark matter candidates that result in detectable cosmic-ray antideuteron fluxes, as well as the status and prospects of current experimental searches. The coalescence model of antideuteron production and the influence of antideuteron measurements at particle colliders are discussed. This is followed by a review of the modeling of antideuteron pr...

  13. Prompt TeV Emission from Cosmic Rays Accelerated by Gamma Ray Bursts Interacting with Surrounding Stellar Wind

    E-Print Network [OSTI]

    Soebur Razzaque; Olga Mena; Charles D. Dermer

    2008-11-24

    Protons accelerated in the internal shocks of a long duration gamma ray burst can escape the fireball as cosmic rays by converting to neutrons. Hadronic interactions of these neutrons inside a stellar wind bubble created by the progenitor star will produce TeV gamma rays via neutral meson decay and synchrotron radiation by charged pion-decay electrons in the wind magnetic field. Such gamma rays should be observable from nearby gamma ray bursts by currently running and upcoming ground-based detectors.

  14. Astrophysical Sources of Cosmic Rays and Related Measurements with the Pierre Auger Observatory

    SciTech Connect (OSTI)

    Abraham, : J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Ahn, E.J.; Allard, D.; Allekotte, I.; Allen, J.; Alvarez-Muniz, J.; Ambrosio, M.; Anchordoqui, L.

    2009-06-01

    These are presentations to be presented at the 31st International Cosmic Ray Conference, in Lodz, Poland during July 2009. It consists of the following presentations: (1) Correlation of the highest energy cosmic rays with nearby extragalactic objects in Pierre Auger Observatory data; (2) Discriminating potential astrophysical sources of the highest energy cosmic rays with the Pierre Auger Observatory; (3) Intrinsic anisotropy of the UHECR from the Pierre Auger Observatory; (4) Ultra-high energy photon studies with the Pierre Auger Observatory; (5) Limits on the flux of diffuse ultra high energy neutrinos set using the Pierre Auger Observatory; (6) Search for sidereal modulation of the arrival directions of events recorded at the Pierre Auger Observatory; (7) Cosmic Ray Solar Modulation Studies in the Pierre Auger Observatory; (8) Investigation of the Displacement Angle of the Highest Energy Cosmic Rays Caused by the Galactic Magnetic Field; (9) Search for coincidences with astrophysical transients in Pierre Auger Observatory data; and (10) An alternative method for determining the energy of hybrid events at the Pierre Auger Observatory.

  15. A Predictive Analytic Model for the Solar Modulation of Cosmic Rays

    E-Print Network [OSTI]

    Cholis, Ilias; Linden, Tim

    2015-01-01

    An important factor limiting our ability to understand the production and propagation of cosmic rays pertains to the effects of heliospheric forces, commonly known as solar modulation. The solar wind is capable of generating time and charge-dependent effects on the spectrum and intensity of low energy ($\\lsim$ 10 GeV) cosmic rays reaching Earth. Previous analytic treatments of solar modulation have utilized the force-field approximation, in which a simple potential is adopted whose amplitude is selected to best fit the cosmic-ray data taken over a given period of time. Making use of recently available cosmic-ray data from the Voyager 1 spacecraft, along with measurements of the heliospheric magnetic field and solar wind, we construct a time, charge and rigidity-dependent model of solar modulation that can be directly compared to data from a variety of cosmic-ray experiments. We provide a simple analytic formula that can be easily utilized in a variety of applications, allowing us to better predict the effects...

  16. Upper limits on the total cosmic-ray luminosity of individual sources

    SciTech Connect (OSTI)

    Anjos, R.C.; De Souza, V.; Supanitsky, A.D. E-mail: vitor@ifsc.usp.br

    2014-07-01

    In this paper, upper limits on the total luminosity of ultra-high-energy cosmic-rays (UHECR) E > 10{sup 18} eV) are determined for five individual sources. The upper limit on the integral flux of GeV--TeV gamma-rays is used to extract the upper limit on the total UHECR luminosity of individual sources. The correlation between upper limit on the integral GeV--TeV gamma-ray flux and upper limit on the UHECR luminosity is established through the cascading process that takes place during propagation of the cosmic rays in the background radiation fields, as explained in reference [1]. Twenty-eight sources measured by FERMI-LAT, VERITAS and MAGIC observatories have been studied. The measured upper limit on the GeV--TeV gamma-ray flux is restrictive enough to allow the calculation of an upper limit on the total UHECR cosmic-ray luminosity of five sources. The upper limit on the UHECR cosmic-ray luminosity of these sources is shown for several assumptions on the emission mechanism. For all studied sources an upper limit on the ultra-high-energy proton luminosity is also set.

  17. Neutrino and cosmic-ray release from gamma-ray bursts: Time-dependent simulations

    SciTech Connect (OSTI)

    Asano, Katsuaki [Institute for Cosmic Ray Research, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582 (Japan); Mészáros, Peter, E-mail: asanok@icrr.u-tokyo.ac.jp, E-mail: nnp@psu.edu [Department of Astronomy and Astrophysics, Department of Physics, Center for Particle and Gravitational Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States)

    2014-04-10

    We revisit the neutrino and ultra-high-energy cosmic-ray (UHECR) production from gamma-ray bursts (GRBs) with time-dependent simulations for the proton-induced cascades. This method can generate self-consistent photon, neutrino, and escaped neutron spectra. To obtain the integrated background spectra, we take into account the distributions of the burst luminosity and pulse duration timescale. A benchmark case with standard GRB luminosity function, a bulk Lorentz factor ? = 300, and a proton to gamma-ray luminosity fraction f{sub p} = 10 is consistent with both the neutrino upper limits and the observed UHECR intensity at ?10{sup 20} eV, while requiring a different type of UHECR source at the ankle. For the benchmark case, the GRBs in the bright end of the luminosity function, which contribute most of the neutrinos, have their photon spectrum substantially distorted by secondary photons. Such bright GRBs are few in number, and reducing their f{sub p} eliminates the distortion and reduces the neutrino production. Even if we neglect the contribution of the brightest GRBs, the UHECR production rate at energies corresponding to the Greisen-Zatsepin-Kuzmin limit is almost unchanged. These nominal GRB models, especially with L {sub iso} ? 10{sup 53} erg s{sup –1}, appear to meet the current constraints as far as being candidate UHECR sources above the ankle energy.

  18. Future Extensive Air Shower arrays: from Gamma-Ray Astronomy to Cosmic Rays

    E-Print Network [OSTI]

    Di Sciascio, Giuseppe

    2015-01-01

    Despite large progresses in building new detectors and in the analysis techniques, the key questions concerning the origin, acceleration and propagation of Galactic Cosmic Rays are still open. A number of new EAS arrays is in progress. The most ambitious and sensitive project between them is LHAASO, a new generation multi-component experiment to be installed at very high altitude in China (Daocheng, Sichuan province, 4400 m a.s.l.). The experiment will face the open problems through a combined study of photon- and charged particle-induced extensive air showers in the wide energy range 10$^{11}$ - 10$^{18}$ eV. In this paper the status of the experiment will be summarized, the science program presented and the outlook discussed in comparison with leading new projects.

  19. Future Extensive Air Shower arrays: from Gamma-Ray Astronomy to Cosmic Rays

    E-Print Network [OSTI]

    Giuseppe Di Sciascio

    2015-03-18

    Despite large progresses in building new detectors and in the analysis techniques, the key questions concerning the origin, acceleration and propagation of Galactic Cosmic Rays are still open. A number of new EAS arrays is in progress. The most ambitious and sensitive project between them is LHAASO, a new generation multi-component experiment to be installed at very high altitude in China (Daocheng, Sichuan province, 4400 m a.s.l.). The experiment will face the open problems through a combined study of photon- and charged particle-induced extensive air showers in the wide energy range 10$^{11}$ - 10$^{18}$ eV. In this paper the status of the experiment will be summarized, the science program presented and the outlook discussed in comparison with leading new projects.

  20. Dissipation of Magnetohydrodynamic Waves on Energetic Particles: Impact on Interstellar Turbulence and Cosmic Ray Transport

    E-Print Network [OSTI]

    V. S. Ptuskin; I. V. Moskalenko; F. C. Jones; A. W. Strong; V. N. Zirakashvili

    2006-01-21

    The physical processes involved in diffusion of Galactic cosmic rays in the interstellar medium are addressed. We study the possibility that the nonlinear MHD cascade sets the power-law spectrum of turbulence which scatters charged energetic particles. We find that the dissipation of waves due to the resonant interaction with cosmic ray particles may terminate the Kraichnan-type cascade below wavelengths 10^13 cm. The effect of this wave dissipation has been incorporated in the GALPROP numerical propagation code in order to asses the impact on measurable astrophysical data. The energy-dependence of the cosmic-ray diffusion coefficient found in the resulting self-consistent model may explain the peaks in the secondary to primary nuclei ratios observed at about 1 GeV/nucleon.

  1. High energy cosmic ray self-confinement close to extragalactic sources

    E-Print Network [OSTI]

    Blasi, P; D'Angelo, M

    2015-01-01

    The ultra-high energy cosmic rays observed at the Earth are most likely accelerated in extra-galactic sources. For the typical luminosities invoked for such sources, the electric current associated to the flux of cosmic rays that leave them is large. The associated plasma instabilities create magnetic fluctuations that can efficiently scatter particles. We argue that this phenomenon forces cosmic rays to be self-confined in the source proximity for energies $Eenergies $E

  2. On the Observation of the Cosmic Ray Anisotropy below 10$^{15}$ eV

    E-Print Network [OSTI]

    G. Di Sciascio; R. Iuppa

    2014-07-08

    The measurement of the anisotropy in the arrival direction of cosmic rays is complementary to the study of their energy spectrum and chemical composition to understand their origin and propagation. It is also a tool to probe the structure of the magnetic fields through which cosmic rays travel. As cosmic rays are mostly charged nuclei, their trajectories are deflected by the action of galactic magnetic field they propagate through before reaching the Earth atmosphere, so that their detection carries directional information only up to distances as large as their gyro-radius. If cosmic rays below $10^{15}{\\rm\\,eV}$ are considered and the local galactic magnetic field ($\\sim3{\\rm\\,\\mu G}$) is accounted for, gyro-radii are so short that isotropy is expected. At most, a weak di-polar distribution may exist, reflecting the contribution of the closest CR sources. However, a number of experiments observed an energy-dependent \\emph{"large scale"} anisotropy in the sidereal time frame with an amplitude of about 10$^{-4}$ - 10$^{-3}$, revealing the existence of two distinct broad regions: an excess distributed around 40$^{\\circ}$ to 90$^{\\circ}$ in Right Ascension (commonly referred to as "tail.in" excess) and a deficit (the "loss cone") around 150$^{\\circ}$ to 240$^{\\circ}$ in Right Ascension. In recent years the Milagro and ARGO-YBJ collaborations reported the of a "medium" scale anisotropy inside the tail-in region. The observation of such small features has been recently claimed by the IceCube experiment also in the Southern hemisphere. So far, no theory of cosmic rays in the Galaxy exists which is able to explain the origin of these different anisotropies leaving the standard model of cosmic rays and that of the galactic magnetic field unchanged at the same time.

  3. Review of the theoretical and experimental status of dark matter identification with cosmic-ray antideuterons

    E-Print Network [OSTI]

    T. Aramaki; S. Boggs; S. Bufalino; L. Dal; P. von Doetinchem; F. Donato; N. Fornengo; H. Fuke; M. Grefe; C. Hailey; B. Hamilton; A. Ibarra; J. Mitchell; I. Mognet; R. A. Ong; R. Pereira; K. Perez; A. Putze; A. Raklev; P. Salati; M. Sasaki; G. Tarle; A. Urbano; A. Vittino; S. Wild; W. Xue; K. Yoshimura

    2015-05-28

    Recent years have seen increased theoretical and experimental effort towards the first-ever detection of cosmic-ray antideuterons, in particular as an indirect signature of dark matter annihilation or decay. In contrast to indirect dark matter searches using positrons, antiprotons, or gamma-rays, which suffer from relatively high and uncertain astrophysical backgrounds, searches with antideuterons benefit from very suppressed conventional backgrounds, offering a potential breakthrough in unexplored phase space for dark matter. This article is based on the first dedicated cosmic-ray antideuteron workshop, which was held at UCLA in June 2014. It reviews broad classes of dark matter candidates that result in detectable cosmic-ray antideuteron fluxes, as well as the status and prospects of current experimental searches. The coalescence model of antideuteron production and the influence of antideuteron measurements at particle colliders are discussed. This is followed by a review of the modeling of antideuteron propagation through the magnetic fields, plasma currents, and molecular material of our Galaxy, the solar system, the Earth's geomagnetic field, and the atmosphere. Finally, the three ongoing or planned experiments that are sensitive to cosmic-ray antideuterons, BESS, AMS-02, and GAPS, are detailed. As cosmic-ray antideuteron detection is a rare event search, multiple experiments with orthogonal techniques and backgrounds are essential. Many theoretical and experimental groups have contributed to these studies over the last decade, this review aims to provide the first coherent discussion of the relevant dark matter theories that antideuterons probe, the challenges to predictions and interpretations of antideuteron signals, and the experimental efforts toward cosmic antideuteron detection.

  4. 38th Int. Conf. on Vacuum UV and X-ray Physics - VUVX2013

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservationBio-InspiredAtmosphericdevicesPPONeApril351 Substation Demolition -- B Roll38th Int.

  5. Cosmic-ray pitch-angle scattering in imbalanced MHD turbulence simulations

    E-Print Network [OSTI]

    Weidl, Martin S; Teaca, Bogdan; Schlickeiser, Reinhard

    2015-01-01

    Pitch-angle scattering rates for cosmic-ray particles in magnetohydrodynamic (MHD) simulations with imbalanced turbulence are calculated for fully evolving electromagnetic turbulence. We compare with theoretical predictions derived from the quasilinear theory of cosmic-ray diffusion for an idealized slab spectrum and demonstrate how cross helicity affects the shape of the pitch-angle diffusion coefficient. Additional simulations in evolving magnetic fields or static field configurations provide evidence that the scattering anisotropy in imbalanced turbulence is not primarily due to coherence with propagating Alfven waves, but an effect of the spatial structure of electric fields in cross-helical MHD turbulence.

  6. Isotopic Composition of Light Nuclei in Cosmic Rays: Results from AMS-01

    E-Print Network [OSTI]

    ,

    2011-01-01

    The variety of isotopes in cosmic rays allows us to study different aspects of the processes that cosmic rays undergo between the time they are produced and the time of their arrival in the heliosphere. In this paper we present measurements of the isotopic ratios 2H/4He, 3He/4He, 6Li/7Li, 7Be/(9Be+10Be) and 10B/11B in the range 0.2-1.4 GeV of kinetic energy per nucleon. The measurements are based on the data collected by the Alpha Magnetic Spectrometer, AMS-01, during the STS-91 flight in 1998 June.

  7. Isotopic Composition of Light Nuclei in Cosmic Rays: Results from AMS-01

    E-Print Network [OSTI]

    The AMS-01 Collaboration

    2011-06-12

    The variety of isotopes in cosmic rays allows us to study different aspects of the processes that cosmic rays undergo between the time they are produced and the time of their arrival in the heliosphere. In this paper we present measurements of the isotopic ratios 2H/4He, 3He/4He, 6Li/7Li, 7Be/(9Be+10Be) and 10B/11B in the range 0.2-1.4 GeV of kinetic energy per nucleon. The measurements are based on the data collected by the Alpha Magnetic Spectrometer, AMS-01, during the STS-91 flight in 1998 June.

  8. Consequences of parton's saturation and string's percolation on the developments of cosmic ray showers

    E-Print Network [OSTI]

    C. Pajares; D. Sousa; R. A. Vázquez

    2000-05-31

    At high gluon or string densities, gluons' saturation or the strong interaction among strings, either forming colour ropes or giving rise to string's percolation, induces a strong suppression in the particle multiplicities produced at high energy. This suppression implies important modifications on cosmic ray shower development. In particular, it is shown that it affects the depth of maximum, the elongation rate, and the behaviour of the number of muons at energies around 10^{17}-10^{18} eV. The existing cosmic ray data point out in the same direction.

  9. Cosmic ray spectrum by energy scattered by EAS particles in the atmosphere and galactic model

    E-Print Network [OSTI]

    S. P. Knurenko; A. A. Ivanov; A. V. Sabourov

    2007-11-16

    The differential energy spectrum of cosmic rays from Cherenkov radiation measurements in EAS in the energy range of 10^15-10^20eV has been compared with an anomalous diffusion model for the particles in interstellar space having fractal properties (Lagutin et al, 2001). The close association between experimental data and calculated "all particle" spectra in form at E(0) (10^15-10^18)eV is found. In this case, the average mass composition of cosmic rays calculated by five components does not contradict the average mass composition from experimental data which was obtained by several of EAS characteristics in that energy region.

  10. A Small Multi-Wire Telescope for High Energy Cosmic Ray Muon Detection

    E-Print Network [OSTI]

    Maghrabi, Abdullrahnan; Aldosari, A; Almuteri, M

    2016-01-01

    Different types of ground-based detectors have been developed and deployed around the world to monitor and study CR variations. We have designed, constructed and operated a three layer small (20x20 cm2) multiwire proportional chamber MWPC telescope for cosmic ray muon observations. In this paper, the technical aspects of this detector will be briefly discussed. The abilities of the telescope in detecting high nergy cosmic ray muons (primaries higher than 20 GeV) were established. The telescope performs well in this sense and showed comparable results with a 1 m2 scintillator detector.

  11. OBSERVATION OF COSMIC-RAY ANISOTROPY WITH THE ICETOP AIR SHOWER ARRAY

    E-Print Network [OSTI]

    Aartsen, M. G.; Besson, David Zeke

    2013-02-15

    The Astrophysical Journal, 765:55 (9pp), 2013 March 1 doi:10.1088/0004-637X/765/1/55 C© 2013. The American Astronomical Society. All rights reserved. Printed in the U.S.A. OBSERVATION OF COSMIC-RAY ANISOTROPY WITH THE ICETOP AIR SHOWER ARRAY M. G...; accepted 2012 December 16; published 2013 February 15 ABSTRACT We report on the observation of anisotropy in the arrival direction distribution of cosmic rays at PeV energies. The analysis is based on data taken between 2009 and 2012 with the IceTop air...

  12. The Hadronic Models for Cosmic Ray Physics: the FLUKA Code Solutions

    SciTech Connect (OSTI)

    Battistoni, G.; Garzelli, M.V.; Gadioli, E.; Muraro, S.; Sala, P.R.; Fasso, A.; Ferrari, A.; Roesler, S.; Cerutti, F.; Ranft, J.; Pinsky, L.S.; Empl, A.; Pelliccioni, M.; Villari, R.; /INFN, Milan /Milan U. /SLAC /CERN /Siegen U. /Houston U. /Frascati /ENEA, Frascati

    2007-01-31

    FLUKA is a general purpose Monte Carlo transport and interaction code used for fundamental physics and for a wide range of applications. These include Cosmic Ray Physics (muons, neutrinos, EAS, underground physics), both for basic research and applied studies in space and atmospheric flight dosimetry and radiation damage. A review of the hadronic models available in FLUKA and relevant for the description of cosmic ray air showers is presented in this paper. Recent updates concerning these models are discussed. The FLUKA capabilities in the simulation of the formation and propagation of EM and hadronic showers in the Earth's atmosphere are shown.

  13. Production of A=6,7 Nuclides in the Alpha + Alpha Reaction and Cosmic Ray Nucleosynthesis

    E-Print Network [OSTI]

    David J. Mercer; Sam M. Austin; J. A. Brown; S. A. Danczyk; S. E. Hirzebruck; J. H. Kelley; T. Suomijarvi; D. A. Roberts; T. P Walker

    2001-04-03

    Cross sections for production of 6He, 6Li, 7Li, and 7Be in the alpha+alpha reaction were measured at bombarding energies of 159.3, 279.6, and 619.8 MeV, and are found to decrease rapidly with increasing energy. These cross sections are essential for the calculation of the rate of nucleosynthesis of the lithium isotopes in the cosmic rays and thereby play a key role in our understanding of the synthesis of Li, Be, and B. The results for 6Li differ significantly from the tabulated values commonly used in cosmic-ray production calculations and lead to lower production of 6Li.

  14. Air fluorescence relevant for cosmic-ray detection--Summary of the 5th fluorescence workshop, El Escorial 2007

    E-Print Network [OSTI]

    Hörandel, Jörg R.

    Air fluorescence relevant for cosmic-ray detection--Summary of the 5th fluorescence workshop, El August 2008 Keywords: Fluorescence yield Air showers a b s t r a c t High-energy cosmic rays with energies exceeding 1017 eV are frequently observed by measurements of the fluorescence light induced by air

  15. Propagation of super-high-energy cosmic rays in the Galaxy Jorg R. Horandel a,*, Nikolai N. Kalmykov b

    E-Print Network [OSTI]

    Hörandel, Jörg R.

    for the propagation in the magnetic fields. This method works best for the highest energy particles, since the timePropagation of super-high-energy cosmic rays in the Galaxy Jo¨rg R. Ho¨randel a,*, Nikolai N Available online 27 October 2006 Abstract The propagation of high-energy cosmic rays in the Galaxy

  16. Occupancy of a Large Liquid Argon TPC due to Cosmic Rays Kirk T McDonald (kirkmcd@princeton.edu)

    E-Print Network [OSTI]

    McDonald, Kirk

    of the cryogenic tank is not below grade. Such a surface tank is exposed to a flux of cosmic rays1 (mostly muons requires at a shield of about 10 m of dirt. Options to deal with the cosmic-ray problem include: 1. Solve

  17. Physics from the Very-High Energy Cosmic-Ray Shadows of the Moon and Sun with Milagro

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    Physics from the Very-High Energy Cosmic-Ray Shadows of the Moon and Sun with Milagro by Grant E. I'd also like to thank Jonathan Roberts for helpful comments on the Sun. After moving into a new of the Moon and Sun in TeV cosmic rays are unique probes of the character of these particles and the magnetic

  18. arXiv:astro-ph/0610865v130Oct2006 Power Laws and the Cosmic Ray Energy

    E-Print Network [OSTI]

    arXiv:astro-ph/0610865v130Oct2006 Power Laws and the Cosmic Ray Energy Spectrum J. D. Hague a,1 B and preliminary Auger Cosmic Ray Energy spectra in an attempt to find deviation from a pure power-law. The first spectrum suggests deviation from a power-law. However, potentially large systematics on the relative energy

  19. 32ND INTERNATIONAL COSMIC RAY CONFERENCE, BEIJING 2011 Towards the all-particle energy spectrum of cosmic rays measured with LORA --an air

    E-Print Network [OSTI]

    Hörandel, Jörg R.

    of cosmic rays measured with LORA -- an air shower array for LOFAR J.R. H ¨ORANDEL1 , A. CORSTANJE1 , L. B.horandel@astro.ru.nl Abstract: A small air shower array has been installed in the core of the LOFAR radio telescope in the Netherlands. The objective is to contribute to the investigation of radio emission from extensive air showers

  20. EMMA an underground cosmic-ray experiment T. Enqvista

    E-Print Network [OSTI]

    Usoskin, Ilya G.

    . Trzaskad , I. Usoskinf , a Centre for Underground Physics at Pyh¨asalmi (CUPP), University of Oulu, Finland¨askyl¨a, Finland e Kurchatov Institute, Moscow, Russia f Sodankyl¨a Geophysical Observatory (SGO), University of Oulu, Oulu, Finland g Radiation and Nuclear Safety Authority (STUK), Helsinki, Finland A new cosmic

  1. Modeling high-energy cosmic ray induced terrestrial and atmospheric neutron flux: A lookup table

    E-Print Network [OSTI]

    Andrew Overholt; Adrian Melott; Dimitra Atri

    2013-06-05

    Under current conditions, the cosmic ray spectrum incident on the Earth is dominated by particles with energies solar flares, supernovae and gamma ray bursts produce high energy cosmic rays (HECRs) with drastically higher energies. The Earth is likely episodically exposed to a greatly increased HECR flux from such events, some of which lasting thousands to millions of years. The air showers produced by HECRs ionize the atmosphere and produce harmful secondary particles such as muons and neutrons. Neutrons currently contribute a significant radiation dose at commercial passenger airplane altitude. With higher cosmic ray energies, these effects will be propagated to ground level. This work shows the results of Monte Carlo simulations quantifying the neutron flux due to high energy cosmic rays at various primary energies and altitudes. We provide here lookup tables that can be used to determine neutron fluxes from primaries with total energies 1 GeV - 1 PeV. By convolution, one can compute the neutron flux for any arbitrary CR spectrum. Our results demonstrate that deducing the nature of primaries from ground level neutron enhancements would be very difficult.

  2. A Gamma-Ray Burst/Pulsar for Cosmic-Ray Positrons with a Dark Matter-like Spectrum

    E-Print Network [OSTI]

    Kunihito Ioka

    2010-06-15

    We propose that a nearby gamma-ray burst (GRB) or GRB-like (old, single and short-lived) pulsar/supernova remnant/microquasar about 10^{5-6} years ago may be responsible for the excesses of cosmic-ray positrons and electrons recently observed by the PAMELA, ATIC/PPB-BETS, Fermi and HESS experiments. We can reproduce the smooth Fermi/HESS spectra as well as the spiky ATIC/PPB-BETS spectra. The spectra have a sharp cutoff that is similar to the dark matter predictions, sometimes together with a line (not similar), since higher energy cosmic-rays cool faster where the cutoff/line energy marks the source age. A GRB-like astrophysical source is expected to have a small but finite spread in the cutoff/line as well as anisotropy in the cosmic-ray and diffuse gamma-ray flux, providing a method for the Fermi and future CALET experiments to discriminate between dark matter and astrophysical origins.

  3. Environmental limits on the non-resonant cosmic-ray current-driven instability

    E-Print Network [OSTI]

    B. Reville; J. G. Kirk; P. Duffy; S. O'Sullivan

    2008-02-22

    We investigate the so-called non-resonant cosmic-ray streaming instability, first discussed by Bell (2004). The extent to which thermal damping and ion-neutral collisions reduce the growth of this instability is calculated. Limits on the growth of the non-resonant mode in SN1006 and RX J1713.7-3946 are presented.

  4. 30TH INTERNATIONAL COSMIC RAY CONFERENCE In-orbit performances of the magnetic spectrometer of PAMELA

    E-Print Network [OSTI]

    Morselli, Aldo

    of the spectrometer of PAMELA is generated by a permanent magnet composed of five identical modules put one on top microstrip sensors, which are placed inside the magnetic cavity of a permanent magnet. The apparatus is used30TH INTERNATIONAL COSMIC RAY CONFERENCE In-orbit performances of the magnetic spectrometer

  5. 30TH INTERNATIONAL COSMIC RAY CONFERENCE The Second Level Trigger of the PAMELA Space Experiment

    E-Print Network [OSTI]

    Morselli, Aldo

    . The experiment has a foreseen lifetime of at least 3 years. PAMELA is built around a permanent magnet silicon a permanent magnet spectrometer with a variety of specialized detec- tors [3]. In particular below the tracker, cosmic ray generation and propa- gation in our galaxy and the solar system, and to the study of solar

  6. Reply to "Comment on `Correlation between Compact Radio Quasars and Ultra-High Energy Cosmic Rays'"

    E-Print Network [OSTI]

    Glennys R. Farrar; Peter L. Biermann

    1999-01-22

    We discuss the rationale for the energy cuts used in the previous study of directional correlation of the five highest energy cosmic ray events with compact, radio quasars. We check the consistency of the next three most energetic events which just missed those cuts, with the correlation hypothesis. Agreement between expected and observed properties of these events is good.

  7. Explanation of the local galactic cosmic ray energy spectra measured by Voyager 1. I. Protons

    SciTech Connect (OSTI)

    Schlickeiser, R.; Kempf, A. [Institut für Theoretische Physik, Lehrstuhl IV: Weltraum- und Astrophysik, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Webber, W. R., E-mail: rsch@tp4.rub.de, E-mail: ank@tp4.rub.de, E-mail: bwebber@nmsu.edu [Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States)

    2014-05-20

    Almost exactly 100 yr after the original discovery of cosmic rays, the V1 spacecraft has observed, for the first time, the local interstellar medium energy spectra of cosmic ray H, He, C/O nuclei at nonrelativistic kinetic energies, after leaving the heliosphere modulation region on 2012 August 25. We explain these observations by modeling the propagation of these particles in the local Galactic environment with an updated steady-state spatial diffusion model including all particle momentum losses with the local interstellar gas (Coulomb/ionization, pion production, adiabatic deceleration, and fragmentation interactions). Excellent agreement with the V1 cosmic ray H observations is obtained if the solar system resides within a spatially homogeneous layer of distributed cosmic ray sources injecting the same momentum power law ?p {sup –s} with s = 2.24 ± 0.12. The best fit to the V1 H observations also provides an estimate of the characteristic break kinetic energy T{sub C} = 116 ± 27 MeV, representing the transition from ionization/Coulomb energy losses at low energies to pion production and adiabatic deceleration losses in a Galactic wind at high energies. As the determined value is substantially smaller than 217 MeV in the absence of adiabatic deceleration, our results prove the existence of a Galactic wind in the local Galactic environment.

  8. The 28th International Cosmic Ray Conference 1 The Alpha Magnetic Spectrometer on the International

    E-Print Network [OSTI]

    Roma "La Sapienza", Universitŕ di

    The 28th International Cosmic Ray Conference 1 The Alpha Magnetic Spectrometer on the International", I.N.F.N Sez. Roma1, Roma, Italy Abstract The Alpha Magnetic Spectrometer (AMS) is a particle physics Academy Press, Inc. #12;2 Fig. 1. The Alpha Magnetic Spectrometer on the International Space Station. e

  9. On the Low Energy Decrease in Galactic Cosmic Ray Secondary/Primary Ratios

    E-Print Network [OSTI]

    Davis, Andrew J.

    On the Low Energy Decrease in Galactic Cosmic Ray Secondary/Primary Ratios A.J. Davis1 , R for the low energy decrease in esc and attempt to fit the combined, high-resolution measurements of secondary/primary/nucleon). The energy dependence of esc´Eµ is a free parameter in the model, and GCR secondary/primary ratios and spec

  10. The sensitivity of the next generation of lunar Cherenkov observations to UHE neutrinos and cosmic rays

    E-Print Network [OSTI]

    C. W. James; R. J. Protheroe

    2008-02-25

    We present simulation results for the detection of ultra-high energy (UHE) cosmic ray (CR) and neutrino interactions in the Moon by radio-telescopes. We simulate the expected radio signal at Earth from such interactions, expanding on previous work to include interactions in the sub-regolith layer for single dish and multiple telescope systems. For previous experiments at Parkes, Goldstone, and Kalyazin we recalculate the sensitivity to an isotropic flux of UHE neutrinos. Our predicted sensitivity for future experiments using the Australia Telescope Compact Array (ATCA) and the Australian SKA Pathfinder (ASKAP) indicate these instruments will be able to detect the more optimistic UHE neutrino flux predictions, while the Square Kilometre Array (SKA) will also be sensitive to all bar one prediction of a diffuse `cosmogenic', or `GZK', neutrino flux. Current uncertainties concerning the structure and roughness of the lunar surface prevents an accurate calculation of the sensitivity of the lunar Cherenkov technique for UHE cosmic ray astronomy at high frequencies. However, below 200 MHz we find that the proposed SKA low-frequency aperture array should be able to detect events above 56 EeV at a rate about 30 times that of the current Pierre Auger Observatory. This would allow directional analysis of UHE cosmic rays, and investigation of correlations with putative cosmic ray source populations, to be conducted with very high statistics.

  11. Cosmic-ray propagation at small scale: a support for protostellar disc formation

    E-Print Network [OSTI]

    Padovani, Marco; Hennebelle, Patrick; Commercon, Benoît; Joos, Marc

    2015-01-01

    As long as magnetic fields remain frozen into the gas, the magnetic braking prevents the formation of protostellar discs. This condition is subordinate to the ionisation fraction characterising the inmost parts of a collapsing cloud. The ionisation level is established by the number and the energy of the cosmic rays able to reach these regions. Adopting the method developed in our previous studies, we computed how cosmic rays are attenuated as a function of column density and magnetic field strength. We applied our formalism to low- and high-mass star formation models obtained by numerical simulations of gravitational collapse that include rotation and turbulence. In general, we found that the decoupling between gas and magnetic fields, condition allowing the collapse to go ahead, occurs only when the cosmic-ray attenuation is taken into account with respect to a calculation in which the cosmic-ray ionisation rate is kept constant. We also found that the extent of the decoupling zone also depends on the dust ...

  12. History of cosmic ray research in Finland I.G. Usoskin a,*, E. Valtonen b

    E-Print Network [OSTI]

    Usoskin, Ilya G.

    History of cosmic ray research in Finland I.G. Usoskin a,*, E. Valtonen b , R. Vainio c , P, Finland b Space Research Laboratory, Department of Physics, University of Turku, Finland c Dept. of Physics, University of Helsinki, Finland d Dept. of Physical Sciences, University of Oulu, Finland

  13. On the Observation of the Cosmic Ray Anisotropy below 10$^{15}$ eV

    E-Print Network [OSTI]

    Di Sciascio, G

    2014-01-01

    The measurement of the anisotropy in the arrival direction of cosmic rays is complementary to the study of their energy spectrum and chemical composition to understand their origin and propagation. It is also a tool to probe the structure of the magnetic fields through which cosmic rays travel. As cosmic rays are mostly charged nuclei, their trajectories are deflected by the action of galactic magnetic field they propagate through before reaching the Earth atmosphere, so that their detection carries directional information only up to distances as large as their gyro-radius. If cosmic rays below $10^{15}{\\rm\\,eV}$ are considered and the local galactic magnetic field ($\\sim3{\\rm\\,\\mu G}$) is accounted for, gyro-radii are so short that isotropy is expected. At most, a weak di-polar distribution may exist, reflecting the contribution of the closest CR sources. However, a number of experiments observed an energy-dependent \\emph{"large scale"} anisotropy in the sidereal time frame with an amplitude of about 10$^{-4...

  14. General Solution of a Fractional Diffusion-Advection Equation for Solar Cosmic-Ray Transport

    E-Print Network [OSTI]

    M. C. Rocca; A. R. Plastino; A. Plastino; A. L. De Paoli

    2014-11-30

    In this effort we exactly solve the fractional diffusion-advection equation for solar cosmic-ray transport proposed in \\cite{LE2014} and give its {\\it general solution} in terms of hypergeometric distributions. Also, we regain all the results and approximations given in \\cite{LE2014} as {\\it particular cases} of our general solution.

  15. Cosmic-ray observations of the heliosphere with the PAMELA experiment

    E-Print Network [OSTI]

    Morselli, Aldo

    Mexico State University, 88003-8001 Las Cruces, NM, USA h Lebedev Physical Institute, RU-119991 Moscow will focus on the solar and heliospheric observation capabilities of PAMELA. Ó 2005 Published by Elsevier Ltd on behalf of COSPAR. Keywords: Cosmic rays; Satellite-borne experiment; Solar wind; Solar energetic

  16. 28th International Cosmic Ray Conference 4245 Relative Nuclear Abundances Measurements Inside Mir

    E-Print Network [OSTI]

    Morselli, Aldo

    ) Moscow State Engineering Physics Institute, Moscow, Russia (7) Russian Space Corporation "Energia parameters: 1. from the cosmic ray flux, depending on long and short term solar phenomena such as solar cycle and Solar Particle Events respectively; 2. from the construction (hull shielding) and orbit

  17. 30TH INTERNATIONAL COSMIC RAY CONFERENCE The Central Laser Facility at the Telescope Array

    E-Print Network [OSTI]

    -8582, Japan 2 Department of Physics, Univ. of Utah, 115 S 1400 E, Salt Lake City, UT 84112-0830, USA shige at the middle of three FD stations has a 355 nm wave- length laser as test beam for FD telescopes. It has is roughly equal to the fluorescence light generated by 1020 eV cosmic ray. Therefore the information about

  18. Energy estimation of UHE cosmic rays using the atmospheric uorescence technique

    E-Print Network [OSTI]

    Energy estimation of UHE cosmic rays using the atmospheric Żuorescence technique C. Song a,*, Z University, New York, NY 10027, USA b High Energy Astrophysics Institute, University of Utah, Salt Lake City use the CORSIKA air shower simulation program to review the method for assigning energies to ultra

  19. ENERGY SPECTRUM OF PRIMARY COSMIC RAYS ABOVE 1017 OBTAINED USING AKENO 20 KM2

    E-Print Network [OSTI]

    OG 6.3-3 ENERGY SPECTRUM OF PRIMARY COSMIC RAYS ABOVE 1017 EV OBTAINED USING AKENO 20 KM2 ARRAY M, Tokyo Institute of Technology, Tokyo 152, Japan . Institute of High Energy Physics, Academia Sinica these showers, 60 of them are initiated by primaries with energies larger than 1019 eV. The energy spectrum

  20. Magnetic fields and cosmic ray anisotropies at TeV energies

    E-Print Network [OSTI]

    Eduardo Battaner; Joaquin Castellano; Manuel Masip

    2014-12-20

    Several cosmic-ray observatories have provided a high accuracy map of the sky at TeV--PeV energies. The data reveals an O(0.1%) deficit from north galactic directions that peaks at 10 TeV and then evolves with the energy, together with other anisotropies at smaller angular scales. Using Boltzmann's equation we derive expressions for the cosmic-ray flux that fit most of these features. The anisotropies depend on the local interstellar magnetic field B_{IS}, on the average galactic field B_{R} in our vicinity, and on the distribution of dominant cosmic-ray sources. We show that the initial dipole anisotropy along B_{IS} can be modulated by changes in the global cosmic ray wind, and that a variation in the dipole direction would imply a given radius of coherence for B_{IS}. We also show that small and medium-scale anisotropies may appear when the full-sky anisotropy finds a turbulence acting as a magnetic lens.

  1. The Cosmic-ray Spectrum: from the knee to the T K Gaisser

    E-Print Network [OSTI]

    [?]. It has been known since the 60s that supernova explosions produce just the right amount of power about the nature of the sources of cosmic rays, about the source of power for their acceleration by Ptuskin at this conference, the numerical result is robust and independent of details of the propagation

  2. Why are we still studying cosmic rays? Pierre Auger Observatory: past, present, future

    E-Print Network [OSTI]

    higher than the Calculated Chance Rate ­ even when the counters were as far as 300 m apart. #12;Large GM;photomultiplier Steel tank Cherenkov Light emission in water 41° When a particle travels faster than the velocity Auger Project A new cosmic ray observatory designed for a high statistics study of the The Highest

  3. Forbush decreases of cosmic rays: Energy dependence of the recovery phase

    E-Print Network [OSTI]

    Hörandel, Jörg R.

    is presented here, based on the ground based data from the World Neutron Monitor Network since 1964 and threeForbush decreases of cosmic rays: Energy dependence of the recovery phase I. G. Usoskin,1 I. Braun statistical studies are in disagreement whether the recovery time does or does not depend on the energy

  4. Detection of high energy cosmic rays with the resonant gravitational wave detector NAUTILUS and EXPLORER

    E-Print Network [OSTI]

    P. Astone; D. Babusci; M. Bassan; P. Bonifazi; G. Cavallari; E. Coccia; S. D'Antonio; V. Fafone; G. Giordano; C. Ligi; A. Marini; G. Mazzitelli; Y. Minenkov; I. Modena; G. Modestino; A. Moleti; G. V. Pallottino; G. Pizzella; L. Quintieri; A. Rocchi; F. Ronga; R. Terenzi; M. Visco

    2008-06-14

    The cryogenic resonant gravitational wave detectors NAUTILUS and EXPLORER, made of an aluminum alloy bar, can detect cosmic ray showers. At temperatures above 1 K, when the material is in the normal conducting state, the measured signals are in good agreement with the values expected based on the cosmic rays data and on the thermo-acoustic model. When NAUTILUS was operated at the temperature of 0.14 K, in superconductive state, large signals produced by cosmic ray interactions, more energetic than expected, were recorded. The NAUTILUS data in this case are in agreement with the measurements done by a dedicated experiment on a particle beam. The biggest recorded event was in EXPLORER and excited the first longitudinal mode to a vibrational energy of about 670 K, corresponding to about 360 TeV absorbed in the bar. Cosmic rays can be an important background in future acoustic detectors of improved sensitivity. At present, they represent a useful tool to verify the gravitational wave antenna performance.

  5. Angle-Time-Energy Images of Ultra-High Energy Cosmic Ray Sources

    E-Print Network [OSTI]

    Guenter Sigl

    1997-12-10

    Substantial amount of information both on the source and on characteristics of intercepting magnetic fields is encoded in the distribution in arrival times, directions, and energies of charged ultra-high energy cosmic rays from discrete sources. We present a numerical approach that allows to extract such information from data from next generation experiments.

  6. Investigation of the cosmic ray ground level enhancements during solar cycle 23

    E-Print Network [OSTI]

    Wang, Jingxiu

    . Introduction It is known that solar energetic particles with energies above several hundred MeV at the top as measured on the surface of the Earth. These highest energy solar proton events (SPEs) are called cosmic ray events associated with 13 GLE events in the current (23rd) solar cycle. 2. Data and identification

  7. Ultrahigh energy cosmic ray nuclei from extragalactic pulsars and the effect of their Galactic counterparts

    SciTech Connect (OSTI)

    Fang, Ke; Olinto, Angela V. [Department of Astronomy and Astrophysics, Kavli Institute for Cosmological Physics, The University of Chicago, Chicago, Illinois 60637 (United States); Kotera, Kumiko, E-mail: kefang@uchicago.edu, E-mail: kotera@iap.fr, E-mail: olinto@kicp.uchicago.edu [Institut d'Astrophysique de Paris, UMR 7095 - CNRS, Université Pierre and Marie Curie, 98 bis boulevard Arago, 75014, Paris (France)

    2013-03-01

    The acceleration of ultrahigh energy nuclei in fast spinning newborn pulsars can explain the observed spectrum of ultrahigh energy cosmic rays and the trend towards heavier nuclei for energies above 10{sup 19} eV as reported by the Auger Observatory. Pulsar acceleration implies a hard injection spectrum ( ? E{sup ?1}) due to pulsar spin down and a maximum energy E{sub max} ? Z 10{sup 19} eV due to the limit on the spin rate of neutron stars. We have previously shown that the escape through the young supernova remnant softens the spectrum, decreases slightly the maximum energy, and generates secondary nuclei. Here we show that the distribution of pulsar birth periods and the effect of propagation in the interstellar and intergalactic media modifies the combined spectrum of all pulsars. By assuming a normal distribution of pulsar birth periods centered at 300 ms, we show that the contribution of extragalactic pulsar births to the ultrahigh energy cosmic ray spectrum naturally gives rise to a contribution to very high energy cosmic rays (VHECRs, between 10{sup 16} and 10{sup 18} eV) by Galactic pulsar births. The required injected composition to fit the observed spectrum depends on the absolute energy scale, which is uncertain, differing between Auger Observatory and Telescope Array. The contribution of Galactic pulsar births can also bridge the gap between predictions for cosmic ray acceleration in supernova remnants and the observed spectrum just below the ankle, depending on the composition of the cosmic rays that escape the supernova remnant and the diffusion behavior of VHECRs in the Galaxy.

  8. PROBING THE COSMIC X-RAY AND MeV GAMMA-RAY BACKGROUND RADIATION...

    Office of Scientific and Technical Information (OSTI)

    ASTROPHYSICS; BACKGROUND RADIATION; BLACK HOLES; CORRELATIONS; COSMIC PHOTONS; GALAXY NUCLEI; GAMMA RADIATION; HARD X RADIATION; KEV RANGE; MEV RANGE; QUASARS; SEYFERT...

  9. Measuring 10-1000 GeV Cosmic Ray Electrons with GLAST/LAT

    E-Print Network [OSTI]

    Alexander A. Moiseev; Jonathan F. Ormes; Igor V. Moskalenko

    2007-06-06

    We present here the capabilities of the GLAST Large Area Telescope to detect cosmic ray high-energy (HE) electrons in the energy range from 10 GeV to 1 TeV. We also discuss the science topics that can be investigated with HE electron data and quantify the results with LAT instrument simulations. The science topics include CR propagation, calibration of the IC gamma-ray model, testing hypotheses regarding the origin of HE energy cosmic-ray electrons, searching for any signature of Kaluza Klein Dark Matter annihilation, and measuring the HE electron anisotropy. We expect to detect ~ 107 electrons above 20 GeV per year of LAT operation.

  10. First results on Cosmic Ray electron spectrum below 20 GeV from the Fermi LAT

    E-Print Network [OSTI]

    Pesce-Rollins, Melissa

    2009-01-01

    Designed to be a successor of the previous flown space based gamma ray detectors, the Fermi Large Area Telescope (LAT) is also an electron detector. Taking advantage of its capability to separate electromagnetic and hadronic signals it is possible to accurately measure the Cosmic Ray electron spectrum. The spectra of primary cosmic ray electrons below 20 GeV is influenced by many local effects such as solar modulation and the geomagnetic cutoff. For energies below a few GeV it is possible to observe the albedo population of electrons which are controlled by the local magnetic field. In this paper we present the LAT electron analysis in particular event selection and validation as well as the first results on the measurement of the electron spectrum below 20 GeV.

  11. Method to extract the primary cosmic ray spectrum from very high energy gamma-ray data and its application to SNR RX J1713.7-3946

    E-Print Network [OSTI]

    F. L. Villante; F. Vissani

    2008-01-04

    Supernova remnants are likely to be the accelerators of the galactic cosmic rays. Assuming the correctness of this hypothesis, we develop a method to extract the parent cosmic ray spectrum from the VHE gamma ray flux emitted by supernova remnants (and other gamma transparent sources). Namely, we calculate semi-analytically the (inverse) operator which relates an arbitrary gamma ray flux to the parent cosmic ray spectrum, without relying on any theoretical assumption about the shape of the cosmic ray and/or photon spectrum. We illustrate the use of this technique by applying it to the young SNR RX J1713.7-3946 which has been observed by H.E.S.S. experiment during the last three years. Specific implementations of the method permit to use as an input either the parameterized VHE gamma ray flux or directly the raw data. The possibility to detect features in the cosmic rays spectrum and the error in the determination of the parent cosmic ray spectrum are also discussed.

  12. Baryon Production at LHC and Very High Energy Cosmic Ray Spectra

    E-Print Network [OSTI]

    Olga I. Piskounova

    2015-01-27

    The spectra of baryons at LHC can explain the features of the proton spectra in cosmic rays (CR). It seems important to study all baryon data that are available from collider experiments in wide range of energies. Transverse momentum spectra of baryons from RHIC ($\\sqrt(s)$=62 and 200 GeV) and from LHC ($\\sqrt(s)$=0.9 and 7 TeV) have been considered. It is seen that the slope of distributions at low $p_T$'s is changing with energy. The QGSM fit of these spectra gives the average transverse momenta which behave as $s^{0.06}$ that is similar to the previously observed behavior of $\\Lambda^0$ hyperon spectra. The change in average transverse momenta that are slowly growing in VHE hadron interactions at CR detectors cannot cause the "knee" in measured cosmic ray proton spectra. In addition, the available data on heavy quark hadron production from LHC-b at $\\sqrt{s}$=7 TeV were also studied. The preliminary dependence of hadron average transverse momenta on their masses at LHC energy is presented. The possible source of cosmic ray antiparticle-to-particle ratios that are growing with energy was analyzed in the framework of QGSM, where the growing ratios are the result of local leading asymmetry between the production spectra of baryons and antibaryons in the kinematical region of proton target fragmentation. In the laboratory system of cosmic ray measurements this spectrum asymmetry will be seen as growing ratio of secondary antiparticle-to-particle spectra until the certain energy of secondaries. This conclusion makes the particle production at the sources of very high energy cosmic protons important, if the interactions with positive target matter would have place in proximity of these sources.

  13. Observation of Small-scale Anisotropy in the Arrival Direction Distribution of TeV Cosmic Rays with HAWC

    E-Print Network [OSTI]

    Abeysekara, A U; Alvarez, C; Álvarez, J D; Arceo, R; Arteaga-Velázquez, J C; Solares, H A Ayala; Barber, A S; Baughman, B M; Bautista-Elivar, N; Belmont, E; BenZvi, S Y; Berley, D; Rosales, M Bonilla; Braun, J; Caballero-Mora, K S; Carramińana, A; Castillo, M; Cotti, U; Cotzomi, J; de la Fuente, E; De Leó, C; DeYoung, T; Hernandez, R Diaz; Díaz-Vélez, J C; Dingus, B L; DuVernois, M A; Ellsworth, R W; Fiorino, D W; Fraija, N; Galindo, A; Garfias, F; González, M M; Goodman, J A; Gussert, M; Hampel-Arias, Z; Harding, J P; Hüntemeyer, P; Hui, C M; Imran, A; Iriarte, A; Karn, P; Kieda, D; Kunde, G J; Lara, A; Lauer, R J; Lee, W H; Lennarz, D; Vargas, H León; Linnemann, J T; Longo, M; Luna-García, R; Malone, K; Marinelli, A; Marinelli, S S; Martinez, H; Martinez, O; Martínez-Castro, J; Matthews, J A J; McEnery, J; Torres, E Mendoza; Miranda-Romagnoli, P; Moreno, E; Mostafá, M; Nellen, L; Newbold, M; Noriega-Papaqui, R; Oceguera-Becerra, T; Patricelli, B; Pelayo, R; Pérez-Pérez, E G; Pretz, J; Riviére, C; Rosa-González, D; Ruiz-Velasco, E; Ryan, J; Salazar, H; Greus, F Salesa; Sandoval, A; Schneider, M; Sinnis, G; Smith, A J; Woodle, K Sparks; Springer, R W; Taboada, I; Toale, P A; Tollefson, K; Torres, I; Ukwatta, T N; Villaseńor, L; Weisgarber, T; Westerhoff, S; Wisher, I G; Wood, J; Yodh, G B; Younk, P W; Zaborov, D; Zepeda, A; Zhou, H

    2014-01-01

    The High-Altitude Water Cherenkov (HAWC) Observatory is sensitive to gamma rays and charged cosmic rays at TeV energies. The detector is still under construction, but data acquisition with the partially deployed detector started in 2013. An analysis of the cosmic-ray arrival direction distribution based on $4.9\\times 10^{10}$ events recorded between June 2013 and February 2014 shows anisotropy at the $10^{-4}$ level on angular scales of about $10^\\circ$. The HAWC cosmic-ray sky map exhibits three regions of significantly enhanced cosmic-ray flux; two of these regions were first reported by the Milagro experiment. A third region coincides with an excess recently reported by the ARGO-YBJ experiment. An angular power spectrum analysis of the sky shows that all terms up to $\\ell=15$ contribute significantly to the excesses.

  14. High Redshift Gamma-Ray Bursts: Observational Signatures of Superconducting Cosmic Strings?

    E-Print Network [OSTI]

    K. S. Cheng; Yun-Wei Yu; T. Harko

    2010-06-11

    The high-redshift gamma-ray bursts (GRBs), GRBs 080913 and 090423, challenge the conventional GRB progenitor models by their short durations, typical for short GRBs, and their high energy releases, typical for long GRBs. Meanwhile, the GRB rate inferred from high-redshift GRBs also remarkably exceeds the prediction of the collapsar model, with an ordinary star formation history. We show that all these contradictions could be eliminated naturally, if we ascribe some high-redshift GRBs to electromagnetic bursts of superconducting cosmic strings. High-redshift GRBs could become a reasonable way to test the superconducting cosmic string model, because the event rate of cosmic string bursts increases rapidly with increasing redshifts, whereas the collapsar rate decreases.

  15. Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter

    SciTech Connect (OSTI)

    Abreu, P.; Aglietta, M.; Ahn, E.J.; Allard, D.; Allekotte, I.; Allen, J.; Alvarez Castillo, J.; Alvarez-Muniz, J.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; /Wisconsin U., Milwaukee /Lisbon, IST

    2010-06-01

    Data collected by the Pierre Auger Observatory through 31 August 2007 showed evidence for anisotropy in the arrival directions of cosmic rays above the Greisen-Zatsepin-Kuzmin energy threshold, 6 x 10{sup 19} eV. The anisotropy was measured by the fraction of arrival directions that are less than 3.1{sup o} from the position of an active galactic nucleus within 75 Mpc (using the Veron-Cetty and Veron 12th catalog). An updated measurement of this fraction is reported here using the arrival directions of cosmic rays recorded above the same energy threshold through 31 December 2009. The number of arrival directions has increased from 27 to 69, allowing a more precise measurement. The correlating fraction is (38{sub -6}{sup +7})%, compared with 21% expected for isotropic cosmic rays. This is down from the early estimate of (69{sub -13}{sup +11})%. The enlarged set of arrival directions is examined also in relation to other populations of nearby extragalactic objects: galaxies in the 2 Microns All Sky Survey and active galactic nuclei detected in hard X-rays by the Swift Burst Alert Telescope. A celestial region around the position of the radiogalaxy Cen A has the largest excess of arrival directions relative to isotropic expectations. The 2-point autocorrelation function is shown for the enlarged set of arrival directions and compared to the isotropic expectation.

  16. Study of the properties of Cosmic rays and solar X-Ray Flares by balloon borne experiments

    E-Print Network [OSTI]

    Chakrabarti, S K; Chakraborty, S; Palit, S; Mondal, S K; Bhattacharya, A; Midya, S; Chakrabarti, S

    2013-01-01

    Indian Centre for Space Physics is engaged in pioneering balloon borne experiments with typical payloads less than ~ 3.5kg. Low cost rubber balloons are used to fly them to a height of about 40km. In a double balloon system, the booster balloon lifts the orbiter balloon to its cruising altitude where data is taken for a longer period of time. In this Paper, we present our first scientific report on the variation of Cosmic Rays and muons with altitude and detection of several solar flares in X-rays between 20keV and 100keV. We found the altitude of the Pfotzer maximum at Tropic of Cancer for cosmic rays and muons and catch several solar flares in hard X-rays. We find that the hard X-ray (> 40keV) sky becomes very transparent above Pfotzer maximum. We find the flare spectrum to have a power-law distribution. From these studies, we infer that valuable scientific research could be carried out in near space using low cost balloon borne experiments. Published in Online version of Indian Journal of Physics.

  17. Search for patterns by combining cosmic-ray energy and arrival directions at the Pierre Auger Observatory

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Samarai, I. Al; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; et al

    2015-06-20

    Energy-dependent patterns in the arrival directions of cosmic rays are searched for using data of the Pierre Auger Observatory. We investigate local regions around the highest-energy cosmic rays with $E \\ge 6 \\times 10^{19}$ eV by analyzing cosmic rays with energies above $E \\ge 5 \\times 10^{18}$ eV arriving within an angular separation of approximately 15$^{\\circ }$ . We characterize the energy distributions inside these regions by two independent methods, one searching for angular dependence of energy-energy correlations and one searching for collimation of energy along the local system of principal axes of the energy distribution. No significant patterns aremore »found with this analysis. As a result, the comparison of these measurements with astrophysical scenarios can therefore be used to obtain constraints on related model parameters such as strength of cosmic-ray deflection and density of point sources.« less

  18. CRaTER: The Cosmic Ray Telescope for the Effects of Radiation Experiment on the Lunar Reconnaissance Orbiter Mission

    E-Print Network [OSTI]

    Spence, H. E.

    The Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on the Lunar Reconnaissance Orbiter (LRO) characterizes the radiation environment to be experienced by humans during future lunar missions. CRaTER measures the ...

  19. Atmospheric consequences of cosmic ray variability in the extragalactic shock model: 2. Revised ionization levels and their consequences

    E-Print Network [OSTI]

    Melott, Adrian L.; Atri, Dimitra; Thomas, Brian C.; Medvedev, Mikhail V.; Wilson, Graham Wallace; Murray, Michael J.

    2010-08-19

    It has been suggested that galactic shock asymmetry induced by our galaxy's infall toward the Virgo Cluster may be a source of periodicity in cosmic ray exposure as the solar system oscillates perpendicular to the galactic plane, thereby, inducing...

  20. Pierre Auger Observatory and Telescope Array: Joint Contributions to the 34th International Cosmic Ray Conference (ICRC 2015)

    E-Print Network [OSTI]

    Abbasi, R U; Abu-Zayyad, T; Allen, M; Azuma, R; Barcikowski, E; Belz, J W; Bergman, D R; Blake, S A; Cady, R; Chae, M J; Cheon, B G; Chiba, J; Chikawa, M; Cho, W R; Fujii, T; Fukushima, M; Goto, T; Hanlon, W; Hayashi, Y; Hayashida, N; Hibino, K; Honda, K; Ikeda, D; Inoue, N; Ishii, T; Ishimori, R; Ito, H; Ivanov, D; Jui, C C H; Kadota, K; Kakimoto, F; Kalashev, O; Kasahara, K; Kawai, H; Kawakami, S; Kawana, S; Kawata, K; Kido, E; Kim, H B; Kim, J H; Kim, J H; Kitamura, S; Kitamura, Y; Kuzmin, V; Kwon, Y J; Lan, J; Lim, S I; Lundquist, J P; Machida, K; Martens, K; Matsuda, T; Matsuyama, T; Matthews, J N; Minamino, M; Mukai, Y; Myers, I; Nagasawa, K; Nagataki, S; Nakamura, T; Nonaka, T; Nozato, A; Ogio, S; Ogura, J; Ohnishi, M; Ohoka, H; Oki, K; Okuda, T; Ono, M; Oshima, A; Ozawa, S; Park, I H; Pshirkov, M S; Rodriguez, D C; Rubtsov, G; Ryu, D; Sagawa, H; Sakurai, N; Scott, L M; Shah, P D; Shibata, F; Shibata, T; Shimodaira, H; Shin, B K; Shin, H S; Smith, J D; Sokolsky, P; Springer, R W; Stokes, B T; Stratton, S R; Stroman, T A; Suzawa, T; Takamura, M; Takeda, M; Takeishi, R; Taketa, A; Takita, M; Tameda, Y; Tanaka, H; Tanaka, K; Tanaka, M; Thomas, S B; Thomson, G B; Tinyakov, P; Tkachev, I; Tokuno, H; Tomida, T; Troitsky, S; Tsunesada, Y; Tsutsumi, K; Uchihori, Y; Udo, S; Urban, F; Vasiloff, G; Wong, T; Yamane, R; Yamaoka, H; Yamazaki, K; Yang, J; Yashiro, K; Yoneda, Y; Yoshida, S; Yoshii, H; Zollinger, R; Zundel, Z; :,; Aab, A; Abreu, P; Aglietta, M; Ahn, E J; Samarai, I Al; Albuquerque, I F M; Allekotte, I; Allison, P; Almela, A; Castillo, J Alvarez; Alvarez-Muńiz, J; Batista, R Alves; Ambrosio, M; Aminaei, A; Anastasi, G A; Anchordoqui, L; Andringa, S; Aramo, C; Arqueros, F; Arsene, N; Asorey, H; Assis, P; Aublin, J; Avila, G; Awal, N; Badescu, A M; Baus, C; Beatty, J J; Becker, K H; Bellido, J A; Berat, C; Bertaina, M E; Bertou, X; Biermann, P L; Billoir, P; Blaess, S G; Blanco, A; Blanco, M; Blazek, J; Bleve, C; Blümer, H; Bohá?ová, M; Boncioli, D; Bonifazi, C; Borodai, N; Brack, J; Brancus, I; Bretz, T; Bridgeman, A; Brogueira, P; Buchholz, P; Bueno, A; Buitink, S; Buscemi, M; Caballero-Mora, K S; Caccianiga, B; Caccianiga, L; Candusso, M; Caramete, L; Caruso, R; Castellina, A; Cataldi, G; Cazon, L; Cester, R; Chavez, A G; Chiavassa, A; Chinellato, J A; Chudoba, J; Cilmo, M; Clay, R W; Cocciolo, G; Colalillo, R; Coleman, A; Collica, L; Coluccia, M R; Conceiçăo, R; Contreras, F; Cooper, M J; Cordier, A; Coutu, S; Covault, C E; Dallier, R; Daniel, B; Dasso, S; Daumiller, K; Dawson, B R; de Almeida, R M; de Jong, S J; De Mauro, G; Neto, J R T de Mello; De Mitri, I; de Oliveira, J; de Souza, V; del Peral, L; Deligny, O; Dhital, N; Di Giulio, C; Di Matteo, A; Diaz, J C; Castro, M L Díaz; Diogo, F; Dobrigkeit, C; Docters, W; D'Olivo, J C; Dorofeev, A; Hasankiadeh, Q Dorosti; Anjos, R C dos; Dova, M T; Ebr, J; Engel, R; Erdmann, M; Erfani, M; Escobar, C O; Espadanal, J; Etchegoyen, A; Falcke, H; Fang, K; Farrar, G; Fauth, A C; Fazzini, N; Ferguson, A P; Fick, B; Figueira, J M; Filevich, A; Filip?i?, A; Fratu, O; Freire, M M; Fujii, T; García, B; García-Gámez, D; Garcia-Pinto, D; Gate, F; Gemmeke, H; Gherghel-Lascu, A; Ghia, P L; Giaccari, U; Giammarchi, M; Giller, M; G?as, D; Glaser, C; Glass, H; Golup, G; Berisso, M Gómez; Vitale, P F Gómez; González, N; Gookin, B; Gordon, J; Gorgi, A; Gorham, P; Gouffon, P; Griffith, N; Grillo, A F; Grubb, T D; Guarino, F; Guedes, G P; Hampel, M R; Hansen, P; Harari, D; Harrison, T A; Hartmann, S; Harton, J L; Haungs, A; Hebbeker, T; Heck, D; Heimann, P; Hervé, A E; Hill, G C; Hojvat, C; Hollon, N; Holt, E; Homola, P; Hörandel, J R; Horvath, P; Hrabovský, M; Huber, D; Huege, T; Insolia, A; Isar, P G; Jandt, I; Jansen, S; Jarne, C; Johnsen, J A; Josebachuili, M; Kääpä, A; Kambeitz, O; Kampert, K H; Kasper, P; Katkov, I; Keilhauer, B; Kemp, E; Kieckhafer, R M; Klages, H O; Kleifges, M; Kleinfeller, J; Krause, R; Krohm, N; Kuempel, D; Mezek, G Kukec; Kunka, N; Awad, A W Kuotb; LaHurd, D; Latronico, L; Lauer, R; Lauscher, M; Lautridou, P; Coz, S Le; Lebrun, D; Lebrun, P; de Oliveira, M A Leigui; Letessier-Selvon, A; Lhenry-Yvon, I; Link, K; Lopes, L; López, R; Casado, A López; Louedec, K; Lucero, A; Malacari, M; Mallamaci, M; Maller, J; Mandat, D; Mantsch, P; Mariazzi, A G; Marin, V; Mari?, I C; Marsella, G; Martello, D; Martinez, H; Bravo, O Martínez; Martraire, D; Meza, J J Masías; Mathes, H J; Mathys, S; Matthews, J; Matthews, J A J; Matthiae, G; Maurizio, D; Mayotte, E; Mazur, P O; Medina, C; Medina-Tanco, G; Meissner, R; Mello, V B B; Melo, D; Menshikov, A; Messina, S; Micheletti, M I; Middendorf, L; Minaya, I A; Miramonti, L; Mitrica, B; Molina-Bueno, L; Mollerach, S; Montanet, F; Morello, C; Mostafá, M; Moura, C A; Müller, G; Muller, M A; Müller, S; Navas, S; Necesal, P; Nellen, L; Nelles, A; Neuser, J; Nguyen, P H

    2015-01-01

    Joint contributions of the Pierre Auger Collaboration and the Telescope Array Collaboration to the 34th International Cosmic Ray Conference, 30 July - 6 August 2015, The Hague, The Netherlands.

  1. Radio detection of high-energy cosmic rays with the Auger Engineering Radio Array (PISA 2015)

    E-Print Network [OSTI]

    Schröder, Frank G

    2016-01-01

    The Auger Engineering Radio Array (AERA) is an enhancement of the Pierre Auger Observatory in Argentina. Covering about View the $17\\,$km$^2$, AERA is the world-largest antenna array for cosmic-ray observation. It consists of more than 150 antenna stations detecting the radio signal emitted by air showers, i.e., cascades of secondary particles caused by primary cosmic rays hitting the atmosphere. At the beginning, technical goals had been in focus: first of all, the successful demonstration that a large-scale antenna array consisting of autonomous stations is feasible. Moreover, techniques for calibration of the antennas and time calibration of the array have been developed, as well as special software for the data analysis. Meanwhile physics goals come into focus. At the Pierre Auger Observatory air showers are simultaneously detected by several detector systems, in particular water-Cherenkov detectors at the surface, underground muon detectors, and fluorescence telescopes, which enables cross-calibration of...

  2. The cosmic ray muon tomography facility based on large scale MRPC detector

    E-Print Network [OSTI]

    Xuewu Wang; Ming Zeng; Zhi Zeng; Yi Wang; Ziran Zhao; Xiaoguang Yue; Zhifei Luo; Hengguan Yi; Baihui Yu; Jianping Cheng

    2015-04-18

    Cosmic ray muon tomography is a novel technology to detect high-Z material. A prototype of TUMUTY with 73.6 cm x 73.6 cm large scale position sensitive MRPC detectors has been developed and is introduced in this paper. Three test kits have been tested and image is reconstructed using MAP algorithm. The reconstruction results show that the prototype is working well and the objects with complex structure and small size (20 mm) can be imaged on it, while the high-Z material is distinguishable from the low-Z one. This prototype provides a good platform for our further studies of the physical characteristics and the performances of cosmic ray muon tomography.

  3. Implementing the De-thinning Method for High Energy Cosmic Rays Extensive Air Shower Simulations

    E-Print Network [OSTI]

    Estupińán, A; Núńez, L A

    2015-01-01

    To simulate the interaction of cosmic rays with the Earth atmosphere requires highly complex computational resources and several statistical techniques have been developed to simplify those calculations. It is common to implement the thinning algorithms to reduce the number of secondary particles by assigning weights to representative particles in the evolution of the cascade. However, since this is a compression method with information loss, it is required to recover the original flux of secondary particles without introduce artificial biases. In this work we present the preliminary results of our version of the de-thinning algorithm for the reconstruction of thinned simulations of extensive air showers initiated by cosmic rays and photons in the energy range $10^{15} < E/\\mathrm{eV} < 10^{17}$.

  4. Comment on AMS02 results support the secondary origin of cosmic ray positrons

    E-Print Network [OSTI]

    Dado, Shlomo

    2015-01-01

    Recently Blum, Katz and Waxman have claimed that the flux of high energy cosmic ray (CR) positrons near Earth that has been measured with the Alpha Magnetic Spectrometer (AMS) aboard the International Space Station can be produced in the collisions of Galactic CR protons and nuclei with the ambient matter in the Galactic interstellar medium (ISM). Their claim was based on an alleged "robust upper limit to the positron flux" which neglected the energy loss of e+'s in the ISM. Inclusion of this energy loss, however, yields a much smaller upper limit, which excludes secondary production in the ISM by the Galactic cosmic rays as the main origin of the CR e^+ flux above 10 GeV.

  5. Measurement of the Cosmic Ray B/C Ratio with the AMS-01 Experiment

    E-Print Network [OSTI]

    N. Tomassetti

    2010-09-09

    The Alpha Magnetic Spectrometer (AMS) is a particle physics detector designed for a high precision measurement of cosmic rays in space. AMS phase-2 (AMS-02) is scheduled to be installed on the ISS for at least three years from September 2010. The AMS-01 precursor experiment operated successfully during a 10-day NASA shuttle flight in June 1998. The orbital inclination was 51.7{\\deg} at a geodetic altitude between 320 to 380 km. Nearly 200,000 Z>2 nuclei were observed by AMS-01 in the rigidity range 1-40 GV. Using these data, it is possible to investigate the relative abundances and the energy spectra of the primary cosmic rays, providing relations with their sources and propagation processes. Preliminary results on the B/C ratio in 0.4-19 GeV/nucleon kinetic energy are presented.

  6. Measurement of the Cosmic Ray B/C Ratio with the AMS-01 Experiment

    E-Print Network [OSTI]

    ,

    2010-01-01

    The Alpha Magnetic Spectrometer (AMS) is a particle physics detector designed for a high precision measurement of cosmic rays in space. AMS phase-2 (AMS-02) is scheduled to be installed on the ISS for at least three years from September 2010. The AMS-01 precursor experiment operated successfully during a 10-day NASA shuttle flight in June 1998. The orbital inclination was 51.7{\\deg} at a geodetic altitude between 320 to 380 km. Nearly 200,000 Z>2 nuclei were observed by AMS-01 in the rigidity range 1-40 GV. Using these data, it is possible to investigate the relative abundances and the energy spectra of the primary cosmic rays, providing relations with their sources and propagation processes. Preliminary results on the B/C ratio in 0.4-19 GeV/nucleon kinetic energy are presented.

  7. ISOTOPIC COMPOSITION OF LIGHT NUCLEI IN COSMIC RAYS: RESULTS FROM AMS-01

    SciTech Connect (OSTI)

    Aguilar, M.; Alcaraz, J.; Berdugo, J. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, CIEMAT, E-28040 Madrid (Spain); Allaby, J. [European Laboratory for Particle Physics, CERN, CH-1211 Geneva 23 (Switzerland); Alpat, B.; Ambrosi, G.; Azzarello, P.; Battiston, R. [INFN-Sezione di Perugia, I-06100 Perugia (Italy); Anderhub, H. [Eidgenoessische Technische Hochschule, ETH Zuerich, CH-8093 Zuerich (Switzerland); Ao, L. [Chinese Academy of Launching Vehicle Technology, CALT, 100076 Beijing (China); Arefiev, A. [Institute of Theoretical and Experimental Physics, ITEP, Moscow 117259 (Russian Federation); Arruda, L.; Barao, F.; Barreira, G. [Laboratorio de Instrumentacao e Fisica Experimental de Particulas, LIP, P-1000 Lisboa (Portugal); Basile, M.; Bellagamba, L. [Dipartimento di Fisica and INFN, Universita di Bologna, I-40126 Bologna (Italy); Bartoloni, A. [INFN-Sezione di Roma, I-00185 Roma (Italy); Becker, R.; Becker, U.; Berges, P., E-mail: Nicola.Tomassetti@pg.infn.it [Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2011-08-01

    The variety of isotopes in cosmic rays allows us to study different aspects of the processes that cosmic rays undergo between the time they are produced and the time of their arrival in the heliosphere. In this paper, we present measurements of the isotopic ratios {sup 2}H/{sup 4}He, {sup 3}He/{sup 4}He, {sup 6}Li/{sup 7}Li, {sup 7}Be/({sup 9}Be+{sup 10}Be), and {sup 10}B/{sup 11}B in the range 0.2-1.4 GeV of kinetic energy per nucleon. The measurements are based on the data collected by the Alpha Magnetic Spectrometer, AMS-01, during the STS-91 flight in 1998 June.

  8. Telescope Array Radar (TARA) Observatory for Ultra-High Energy Cosmic Rays

    SciTech Connect (OSTI)

    Abbasi, R.; Takai, H.; Allen, C.; Beard, L.; Belz, J.; Besson, D.; Byrne, M.; Abou Bakr Othman, M.; Farhang-Boroujeny, B.; Gardner, A.; Gillman, W.H.; Hanlon, W.; Hanson, J.; Jayanthmurthy, C.; Kunwar, S.; Larson, S. L.; Myers, I.; Prohira, S.; Ratzlaff, K.; Sokolsky, P.; Thomson, G. B.; Von Maluski, D.

    2014-08-19

    Construction was completed during summer 2013 on the Telescope Array RAdar (TARA) bi-static radar observatory for Ultra-High Energy Cosmic Rays (UHECR). TARA is co-located with the Telescope Array, the largest “conventional” cosmic ray detector in the Northern Hemisphere, in radio-quiet Western Utah. TARA employs an 8 MW Effective Radiated Power (ERP) VHF transmitter and smart receiver system based on a 250 MS/s data acquisition system in an effort to detect the scatter of sounding radiation by UHECR-induced atmospheric ionization. TARA seeks to demonstrate bi-static radar as a useful new remote sensing technique for UHECRs. In this report, we describe the design and performance of the TARA transmitter and receiver systems.

  9. Telescope Array Radar (TARA) Observatory for Ultra-High Energy Cosmic Rays

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abbasi, R.; Takai, H.; Allen, C.; Beard, L.; Belz, J.; Besson, D.; Byrne, M.; Abou Bakr Othman, M.; Farhang-Boroujeny, B.; Gardner, A.; et al

    2014-08-19

    Construction was completed during summer 2013 on the Telescope Array RAdar (TARA) bi-static radar observatory for Ultra-High Energy Cosmic Rays (UHECR). TARA is co-located with the Telescope Array, the largest “conventional” cosmic ray detector in the Northern Hemisphere, in radio-quiet Western Utah. TARA employs an 8 MW Effective Radiated Power (ERP) VHF transmitter and smart receiver system based on a 250 MS/s data acquisition system in an effort to detect the scatter of sounding radiation by UHECR-induced atmospheric ionization. TARA seeks to demonstrate bi-static radar as a useful new remote sensing technique for UHECRs. In this report, we describe themore »design and performance of the TARA transmitter and receiver systems.« less

  10. COSMIC-RAY-MEDIATED FORMATION OF BENZENE ON THE SURFACE OF SATURN'S MOON TITAN

    SciTech Connect (OSTI)

    Zhou Li; Zheng Weijun; Kaiser, Ralf I.; Landera, Alexander; Mebel, Alexander M.; Liang, Mao-Chang; Yung, Yuk L.

    2010-08-01

    The aromatic benzene molecule (C{sub 6}H{sub 6})-a central building block of polycyclic aromatic hydrocarbon molecules-is of crucial importance for the understanding of the organic chemistry of Saturn's largest moon, Titan. Here, we show via laboratory experiments and electronic structure calculations that the benzene molecule can be formed on Titan's surface in situ via non-equilibrium chemistry by cosmic-ray processing of low-temperature acetylene (C{sub 2}H{sub 2}) ices. The actual yield of benzene depends strongly on the surface coverage. We suggest that the cosmic-ray-mediated chemistry on Titan's surface could be the dominant source of benzene, i.e., a factor of at least two orders of magnitude higher compared to previously modeled precipitation rates, in those regions of the surface which have a high surface coverage of acetylene.

  11. Telescope Array Radar (TARA) Observatory for Ultra-High Energy Cosmic Rays

    SciTech Connect (OSTI)

    Abbasi, R. [Univ. of Utah, Salt Lake City, UT (United States); Takai, H. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Allen, C. [Univ. of Kansas, Lawrence, KS (United States); Beard, L. [Purdue Univ., West Lafayette, IN (United States); Belz, J. [Univ. of Utah, Salt Lake City, UT (United States); Besson, D. [Univ. of Kansas, Lawrence, KS (United States). Moscow Engineering and Physics Inst. (Russian Federation); Byrne, M. [Univ. of Utah, Salt Lake City, UT (United States); Abou Bakr Othman, M. [Univ. of Utah, Salt Lake City, UT (United States); Farhang-Boroujeny, B. [Univ. of Utah, Salt Lake City, UT (United States); Gardner, A. [Univ. of Utah, Salt Lake City, UT (United States); Gillman, W.H. [Gillman and Associates, Salt Lake City, UT (United States); Hanlon, W. [Univ. of Utah, Salt Lake City, UT (United States); Hanson, J. [Univ. of Kansas, Lawrence, KS (United States); Jayanthmurthy, C. [Univ. of Utah, Salt Lake City, UT (United States); Kunwar, S. [Univ. of Kansas, Lawrence, KS (United States); Larson, S. L. [Utah State Univ., Logan, UT (United States); Myers, I. [Univ. of Utah, Salt Lake City, UT (United States); Prohira, S. [Univ. of Kansas, Lawrence, KS (United States); Ratzlaff, K. [Univ. of Kansas, Lawrence, KS (United States); Sokolsky, P. [Univ. of Utah, Salt Lake City, UT (United States); Thomson, G. B. [Univ. of Utah, Salt Lake City, UT (United States); Von Maluski, D. [Univ. of Utah, Salt Lake City, UT (United States)

    2014-12-01

    Construction was completed during summer 2013 on the Telescope Array RAdar (TARA) bi-static radar observatory for Ultra-High Energy Cosmic Rays (UHECR). TARA is co-located with the Telescope Array, the largest “conventional” cosmic ray detector in the Northern Hemisphere, in radio-quiet Western Utah. TARA employs an 8 MW Effective Radiated Power (ERP) VHF transmitter and smart receiver system based on a 250 MS/s data acquisition system in an effort to detect the scatter of sounding radiation by UHECR-induced atmospheric ionization. TARA seeks to demonstrate bi-static radar as a useful new remote sensing technique for UHECRs. In this report, we describe the design and performance of the TARA transmitter and receiver systems.

  12. Recommendations for a Static Cosmic Ray Shield for Enriched Germanium Detectors

    SciTech Connect (OSTI)

    Aguayo Navarrete, Estanislao; Orrell, John L.; Ankney, Austin S.; Berguson, Timothy J.

    2011-09-21

    This document provides a detailed study of cost and materials that could be used to shield the detector material of the international Tonne-scale germanium neutrinoless double-beta decay experiment from hadronic particles from cosmic ray showers at the Earth's surface. This work was motivated by the need for a shield that minimizes activation of the enriched germanium during storage; in particular, when the detector material is being worked on at the detector manufacturer's facility. This work considers two options for shielding the detector material from cosmic ray particles. One option is to use a pre-existing structure already located near the detector manufacturer, such as Canberra Industries in Meriden, Connecticut. The other option is to build a shield onsite at a detector manufacturer's site. This paper presents a cost and efficiency analysis of such construction.

  13. Generation of Mesoscale Magnetic Fields and the Dynamics of Cosmic Ray Acceleration

    E-Print Network [OSTI]

    P. H. Diamond; M. A. Malkov

    2005-06-09

    The problem of the cosmic ray origin is discussed in connection with their acceleration in supernova remnant shocks. The diffusive shock acceleration mechanism is reviewed and its potential to accelerate particles to the maximum energy of (presumably) galactic cosmic rays ($10^{18}eV $) is considered. It is argued that to reach such energies, a strong magnetic field at scales larger than the particle gyroradius must be created as a result of the acceleration process, itself. One specific mechanism suggested here is based on the generation of Alfven wave at the gyroradius scale with a subsequent transfer to longer scales via interaction with strong acoustic turbulence in the shock precursor. The acoustic turbulence in turn, may be generated by Drury instability or by parametric instability of the Alfven waves.

  14. Layered water Cherenkov detector for the study of ultra high energy cosmic rays

    E-Print Network [OSTI]

    Letessier-Selvon, Antoine; Blanco, Miguel; Maris, Ioana C; Settimo, Mariangela

    2014-01-01

    We present a new design for the water Cherenkov detectors that are in use in various cosmic ray observatories. This novel design can provide a significant improvement in the independent measurement of the muonic and electromagnetic component of extensive air showers. From such multi-component data an event by event classification of the primary cosmic ray mass becomes possible. According to popular hadronic interaction models, such as EPOS-LHC or QGSJetII-04, the discriminating power between iron and hydrogen primaries reaches Fisher values of $\\sim$ 2 or above for energies in excess of $10^{19}$ eV with a detector array layout similar to that of the Pierre Auger Observatory.

  15. FOCUSED ACCELERATION OF COSMIC-RAY PARTICLES IN NON-UNIFORM MAGNETIC FIELDS

    SciTech Connect (OSTI)

    Litvinenko, Yuri E. [Department of Mathematics, University of Waikato, P.B. 3105, Hamilton (New Zealand); Schlickeiser, R. [Instituet fuer Theoretische Physik, Lehrstuhl IV: Weltraum- und Astrophysik, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany)

    2011-05-10

    The Fokker-Planck equation for cosmic-ray particles in a spatially varying guide magnetic field in a turbulent plasma is analyzed. An expression is derived for the mean rate of change of particle momentum, caused by the effect of adiabatic focusing in a non-uniform guide field. Results of an earlier diffusion-limit analysis are confirmed, and the physical picture is clarified by working directly with the Fokker-Planck equation. A distributed first-order Fermi acceleration mechanism is identified, which can be termed focused acceleration. If the forward- and backward-propagating waves have equal polarizations, focused acceleration operates when the net cross helicity of an Alfvenic slab turbulence is either negative in a diverging guide field or positive in a converging guide field. It is suggested that focused acceleration can contribute to the formation of the anomalous cosmic-ray spectrum at the heliospheric termination shock.

  16. A Cosmic Ray Test Platform Based on the High Time Resolution MRPC Technology

    E-Print Network [OSTI]

    Tianxiang Chen; Cheng Li; Yongjie Sun; Hongfang Chen; Ming Shao; Zebo Tang; Rongxing Yang; Yi Zhou; Yifei Zhang

    2015-03-13

    In order to test the performance of detector/prototype in environment of laboratory, we design and build a larger area ($90\\times52$ $cm^2$) test platform of cosmic ray based on well-designed Multi-gap Resistive Plate Chamber (MRPC) with an excellent time resolution and a high detection efficiency for the minimum ionizing particles (MIPs). The time resolution of the MRPC module used is tested to be ~80 ps, and the position resolution along the strip is ~5 mm, while the position resolution perpendicular to the strip is ~12.7 mm. The platform constructed by four MRPC modules can be functional for tracking the cosmic rays with a spatial resolution ~6.3 mm, and provide a reference time ~40 ps.

  17. A new multiparametric topological method for determining the primary cosmic ray mass composition in the knee energy region

    E-Print Network [OSTI]

    M. Ambrosio; C. Aramo; D. D'Urso; A. D. Erlykin; F. Guarino; A. Insolia

    2004-10-07

    The determination of the primary cosmic ray mass composition from the characteristics of extensive air showers (EAS), obtained at an observation level in the lower half of the atmosphere, is still an open problem. In this work we propose a new method of the Multiparametric Topological Analysis and show its applicability for the determination of the mass composition of the primary cosmic rays at the PeV energy region.

  18. Air Fluorescence Relevant for Cosmic-Ray Detection - Review of Pioneering Measurements

    E-Print Network [OSTI]

    Fernando Arqueros; Joerg R. Hoerandel; Bianca Keilhauer

    2008-07-24

    Cosmic rays with energies exceeding $10^{17}$ eV are frequently registered by measurements of the fluorescence light emitted by extensive air showers. The main uncertainty for the absolute energy scale of the measured air showers is coming from the fluorescence light yield of electrons in air. The fluorescence light yield has been studied in laboratory experiments. Pioneering measurements between 1954 and 2000 are reviewed.

  19. Temperature fluctuations in HII regions: ionization by Cosmic Rays as a key mechanism

    E-Print Network [OSTI]

    C. Giammanco; J. E. Beckman

    2005-05-18

    We present a detailed model capable of explaining quantitatively the temperature fluctuations observed in luminous, large HII regions. The model is based on two assumptions which we justify on the basis of observations: that the major fraction of the hydrogen in the clouds that form the HII regions is not photoionized and is essentially HI, this HII is lightly ionized by fluxes of low energy cosmic rays (CR) produced by processes originating in the hot stars which illuminate the regions.

  20. Probing Atmospheric Electric Fields in Thunderstorms through Radio Emission from Cosmic-Ray-Induced Air Showers

    E-Print Network [OSTI]

    Schellart, P; Buitink, S; Corstanje, A; Enriquez, J E; Falcke, H; Hörandel, J R; Nelles, A; Rachen, J P; Rossetto, L; Scholten, O; ter Veen, S; Thoudam, S; Ebert, U; Koehn, C; Rutjes, C; Alexov, A; Anderson, J M; Avruch, I M; Bentum, M J; Bernardi, G; Best, P; Bonafede, A; Breitling, F; Broderick, J W; Brüggen, M; Butcher, H R; Ciardi, B; de Geus, E; de Vos, M; Duscha, S; Eislöffel, J; Fallows, R A; Frieswijk, W; Garrett, M A; Grießmeier, J; Gunst, A W; Heald, G; Hessels, J W T; Hoeft, M; Holties, H A; Juette, E; Kondratiev, V I; Kuniyoshi, M; Kuper, G; Mann, G; McFadden, R; McKay-Bukowski, D; McKean, J P; Mevius, M; Moldon, J; Norden, M J; Orru, E; Paas, H; Pandey-Pommier, M; Pizzo, R; Polatidis, A G; Reich, W; Röttgering, H; Scaife, A M M; Schwarz, D J; Serylak, M; Smirnov, O; Steinmetz, M; Swinbank, J; Tagger, M; Tasse, C; Toribio, M C; van Weeren, R J; Vermeulen, R; Vocks, C; Wise, M W; Wucknitz, O; Zarka, P

    2015-01-01

    We present measurements of radio emission from cosmic ray air showers that took place during thunderstorms. The intensity and polarization patterns of these air showers are radically different from those measured during fair-weather conditions. With the use of a simple two-layer model for the atmospheric electric field, these patterns can be well reproduced by state-of-the-art simulation codes. This in turn provides a novel way to study atmospheric electric fields.

  1. Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

    E-Print Network [OSTI]

    Aab, Alexander; Aglietta, Marco; Ahn, Eun-Joo; Samarai, Imen Al; Albuquerque, Ivone; Allekotte, Ingomar; Allison, Patrick; Almela, Alejandro; Castillo, Jesus Alvarez; Alvarez-Muńiz, Jaime; Batista, Rafael Alves; Ambrosio, Michelangelo; Aminaei, Amin; Anastasi, Gioacchino Alex; Anchordoqui, Luis; Andringa, Sofia; Aramo, Carla; Arqueros, Fernando; Arsene, Nicusor; Asorey, Hernán Gonzalo; Assis, Pedro; Aublin, Julien; Avila, Gualberto; Awal, Nafiun; Badescu, Alina Mihaela; Baus, Colin; Beatty, Jim; Becker, Karl Heinz; Bellido, Jose A; Berat, Corinne; Bertaina, Mario Edoardo; Bertou, Xavier; Biermann, Peter; Billoir, Pierre; Blaess, Simon G; Blanco, Alberto; Blanco, Miguel; Blazek, Jiri; Bleve, Carla; Blümer, Hans; Bohá?ová, Martina; Boncioli, Denise; Bonifazi, Carla; Borodai, Nataliia; Brack, Jeffrey; Brancus, Iliana; Bretz, Thomas; Bridgeman, Ariel; Brogueira, Pedro; Buchholz, Peter; Bueno, Antonio; Buitink, Stijn; Buscemi, Mario; Caballero-Mora, Karen S; Caccianiga, Barbara; Caccianiga, Lorenzo; Candusso, Marina; Caramete, Laurentiu; Caruso, Rossella; Castellina, Antonella; Cataldi, Gabriella; Cazon, Lorenzo; Cester, Rosanna; Chavez, Alan G; Chiavassa, Andrea; Chinellato, Jose Augusto; Chudoba, Jiri; Cilmo, Marco; Clay, Roger W; Cocciolo, Giuseppe; Colalillo, Roberta; Coleman, Alan; Collica, Laura; Coluccia, Maria Rita; Conceiçăo, Ruben; Contreras, Fernando; Cooper, Mathew J; Cordier, Alain; Coutu, Stephane; Covault, Corbin; Cronin, James; Dallier, Richard; Daniel, Bruno; Dasso, Sergio; Daumiller, Kai; Dawson, Bruce R; de Almeida, Rogerio M; de Jong, Sijbrand J; De Mauro, Giuseppe; Neto, Joao de Mello; De Mitri, Ivan; de Oliveira, Jaime; de Souza, Vitor; del Peral, Luis; Deligny, Olivier; Dhital, Niraj; Di Giulio, Claudio; Di Matteo, Armando; Diaz, Johana Chirinos; Castro, Mary Lucia Díaz; Diogo, Francisco; Dobrigkeit, Carola; Docters, Wendy; D'Olivo, Juan Carlos; Dorofeev, Alexei; Hasankiadeh, Qader Dorosti; Anjos, Rita dos; Dova, Maria Teresa; Ebr, Jan; Engel, Ralph; Erdmann, Martin; Erfani, Mona; Escobar, Carlos O; Espadanal, Joao; Etchegoyen, Alberto; Falcke, Heino; Fang, Ke; Farrar, Glennys; Fauth, Anderson; Fazzini, Norberto; Ferguson, Andrew P; Fick, Brian; Figueira, Juan Manuel; Filevich, Alberto; Filip?i?, Andrej; Fratu, Octavian; Freire, Martín Miguel; Fujii, Toshihiro; García, Beatriz; Garcia-Gamez, Diego; Garcia-Pinto, Diego; Gate, Florian; Gemmeke, Hartmut; Gherghel-Lascu, Alexandru; Ghia, Piera Luisa; Giaccari, Ugo; Giammarchi, Marco; Giller, Maria; G?as, Dariusz; Glaser, Christian; Glass, Henry; Golup, Geraldina; Berisso, Mariano Gómez; Vitale, Primo F Gómez; González, Nicolás; Gookin, Ben; Gordon, Jacob; Gorgi, Alessio; Gorham, Peter; Gouffon, Philippe; Griffith, Nathan; Grillo, Aurelio; Grubb, Trent D; Guarino, Fausto; Guedes, Germano; Hampel, Matías Rolf; Hansen, Patricia; Harari, Diego; Harrison, Thomas A; Hartmann, Sebastian; Harton, John; Haungs, Andreas; Hebbeker, Thomas; Heck, Dieter; Heimann, Philipp; Herve, Alexander E; Hill, Gary C; Hojvat, Carlos; Hollon, Nicholas; Holt, Ewa; Homola, Piotr; Hörandel, Jörg; Horvath, Pavel; Hrabovský, Miroslav; Huber, Daniel; Huege, Tim; Insolia, Antonio; Isar, Paula Gina; Jandt, Ingolf; Jansen, Stefan; Jarne, Cecilia; Johnsen, Jeffrey A; Josebachuili, Mariela; Kääpä, Alex; Kambeitz, Olga; Kampert, Karl Heinz; Kasper, Peter; Katkov, Igor; Keilhauer, Bianca; Kemp, Ernesto; Kieckhafer, Roger; Klages, Hans; Kleifges, Matthias; Kleinfeller, Jonny; Krause, Raphael; Krohm, Nicole; Kuempel, Daniel; Mezek, Gasper Kukec; Kunka, Norbert; Awad, Alaa Metwaly Kuotb; LaHurd, Danielle; Latronico, Luca; Lauer, Robert; Lauscher, Markus; Lautridou, Pascal; Coz, Sandra Le; Lebrun, Didier; Lebrun, Paul; de Oliveira, Marcelo Augusto Leigui; Letessier-Selvon, Antoine; Lhenry-Yvon, Isabelle; Link, Katrin; Lopes, Luis; López, Rebeca; Casado, Aida López; Louedec, Karim; Lucero, Agustin; Malacari, Max; Mallamaci, Manuela; Maller, Jennifer; Mandat, Dusan; Mantsch, Paul; Mariazzi, Analisa; Marin, Vincent; Mari?, Ioana; Marsella, Giovanni; Martello, Daniele; Martinez, Humberto; Bravo, Oscar Martínez; Martraire, Diane; Meza, Jimmy Masías; Mathes, Hermann-Josef; Mathys, Sebastian; Matthews, James; Matthews, John; Matthiae, Giorgio; Maurizio, Daniela; Mayotte, Eric; Mazur, Peter; Medina, Carlos; Medina-Tanco, Gustavo; Meissner, Rebecca; Mello, Victor; Melo, Diego; Menshikov, Alexander; Messina, Stefano; Micheletti, Maria Isabel; Middendorf, Lukas; Minaya, Ignacio A; Miramonti, Lino; Mitrica, Bogdan; Molina-Bueno, Laura; Mollerach, Silvia; Montanet, François

    2015-01-01

    The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy density is determined from the radio pulses at each observer position and is interpolated using a two dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving per...

  2. Prospects for studies of high-energy solar cosmic rays with ATLAS

    E-Print Network [OSTI]

    S. N. Karpov; Z. M. Karpova; V. A. Bednyakov

    2008-11-18

    The ATLAS detector is intended to verify the standard model and to search for new physics at the Large Hadron Collider (LHC, CERN). In addition to this primary goal, it also allows detection of muons of cosmic rays. On the other hand, unusual bursts of the muon intensity, which correlate with powerful solar flares were recorded and investigated earlier at the Baksan Underground Scintillation Telescope (BUST, INR, Russia) in period from 1981 to 2006 (~2.5 solar cycles). The nature of the muon bursts and their probable relation to the solar cosmic rays is still not quite clear. ATLAS has an excellent muon system allowing search for similar muon bursts. Within the next few years, when the LHC and ATLAS should start to operate, an increase in the solar activity is expected in the new 24th cycle. It increases the probability of finding the muon bursts from powerful flares. Hence ATLAS has a good opportunity to verify the relation of muon bursts to the solar cosmic rays.

  3. Study of the Shadows of the Moon and the Sun with VHE Cosmic Rays

    E-Print Network [OSTI]

    Atkins, R; Berley, D; Chen, M L; Coyne, D G; Delay, R S; Dingus, B L; Dorfan, D E; Ellsworth, R W; Evans, D; Falcone, A D; Fleysher, L; Fleysher, R; Gisler, G; Goodman, J A; Haines, T J; Hoffman, C M; Hugenberger, S; Kelley, L A; Leonor, I; Macri, J R; McConnell, M; McCullough, J F; McEnery, J E; Miller, R S; Mincer, A I; Morales, M F; Némethy, P; Ryan, J M; Schneider, M; Shen, B; Shoup, A L; Sinnis, G; Smith, A J; Sullivan, G W; Thompson, T N; Tümer, T O; Wang, K; Wascko, M O; Westerhoff, S; Williams, D A; Yang, T; Yodh, G B

    1999-01-01

    Milagrito, a prototype for the Milagro detector, operated for 15 months in 1997-8 and collected 8.9 billion events. It was the first extensive air shower (EAS) array sensitive to showers intiated by primaries with energy below 1 TeV. The shadows of the sun and moon observed with cosmic rays can be used to study systematic pointing shifts and measure the angular resolution of EAS arrays. Below a few TeV, the paths of cosmic rays coming toward the earth are bent by the helio- and geo-magnetic fields. This is expected to distort and displace the shadows of the sun and the moon. The moon shadow, offset from the nominal (undeflected) position, has been observed with high statistical significance in Milagrito. This can be used to establish energy calibrations, as well as to search for the anti-matter content of the VHE cosmic ray flux. The shadow of the sun has also been observed with high significance.

  4. Study of the Shadows of the Moon and the Sun with VHE Cosmic Rays

    E-Print Network [OSTI]

    R. Atkins; W. Benbow; D. Berley; M. -L. Chen; D. G. Coyne; R. S. Delay; B. L. Dingus; D. E. Dorfan; R. W. Ellsworth; D. Evans; A. Falcone; L. Fleysher; R. Fleysher; G. Gisler; J. A. Goodman; T. J. Haines; C. M. Hoffman; S. Hugenberger; L. A. Kelley; I. Leonor; J. Macri; M. McConnell; J. F. McCullough; J. E. McEnery; R. S. Miller; A. I. Mincer; M. F. Morales; P. Nemethy; J. M. Ryan; M. Schneider; B. Shen; A. Shoup; G. Sinnis; A. J. Smith; G. W. Sullivan; T. N. Thompson; O. T. Tumer; K. Wang; M. O. Wascko; S. Westerhoff; D. A. Williams; T. Yang; G. B. Yodh

    1999-06-24

    Milagrito, a prototype for the Milagro detector, operated for 15 months in 1997-8 and collected 8.9 billion events. It was the first extensive air shower (EAS) array sensitive to showers intiated by primaries with energy below 1 TeV. The shadows of the sun and moon observed with cosmic rays can be used to study systematic pointing shifts and measure the angular resolution of EAS arrays. Below a few TeV, the paths of cosmic rays coming toward the earth are bent by the helio- and geo-magnetic fields. This is expected to distort and displace the shadows of the sun and the moon. The moon shadow, offset from the nominal (undeflected) position, has been observed with high statistical significance in Milagrito. This can be used to establish energy calibrations, as well as to search for the anti-matter content of the VHE cosmic ray flux. The shadow of the sun has also been observed with high significance.

  5. GZK Photons in the Minimal Ultra High Energy Cosmic Rays Model

    E-Print Network [OSTI]

    Graciela Gelmini; Oleg Kalashev; Dmitry V. Semikoz

    2007-02-18

    In a recently proposed model the cosmic rays spectrum at energies above 10^{18} eV can be fitted with a minimal number of unknown parameters assuming that the extragalactic cosmic rays are only protons with a power law source spectrum ~E^{-alpha} and alpha~2.6. Within this minimal model, after fitting the observed HiRes spectrum with four parameters (proton injection spectrum power law index and maximum energy, minimum distance to sources and evolution parameter) we compute the flux of ultra-high energy photons due to photon-pion production, the GZK photons, for several radio background models and average extragalactic magnetic fields with amplitude between 10^{-11} G and 10^{-9} G. We find the photon fraction to be between 10^{-4} and 10^{-3} in cosmic rays at energies above 10^{19} eV. These small fluxes could only be detected in future experiments like Auger North plus South and EUSO.

  6. The optical depth of the Universe to ultrahigh energy cosmic ray scattering in the magnetized large scale structure

    E-Print Network [OSTI]

    Kumiko Kotera; Martin Lemoine

    2008-04-30

    This paper provides an analytical description of the transport of ultrahigh energy cosmic rays in an inhomogeneously magnetized intergalactic medium. This latter is modeled as a collection of magnetized scattering centers such as radio cocoons, magnetized galactic winds, clusters or magnetized filaments of large scale structure, with negligible magnetic fields in between. Magnetic deflection is no longer a continuous process, it is rather dominated by scattering events. We study the interaction between high energy cosmic rays and the scattering agents. We then compute the optical depth of the Universe to cosmic ray scattering and discuss the phenomological consequences for various source scenarios. For typical parameters of the scattering centers, the optical depth is greater than unity at 5x10^{19}eV, but the total angular deflection is smaller than unity. One important consequence of this scenario is the possibility that the last scattering center encountered by a cosmic ray be mistaken with the source of this cosmic ray. In particular, we suggest that part of the correlation recently reported by the Pierre Auger Observatory may be affected by such delusion: this experiment may be observing in part the last scattering surface of ultrahigh energy cosmic rays rather than their source population. Since the optical depth falls rapidly with increasing energy, one should probe the arrival directions of the highest energy events beyond 10^{20}eV on an event by event basis to circumvent this effect.

  7. Collection: High-Energy Cosmic Ray Event Data from the Pierre Auger Cosmic

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield MunicipalTechnical Report:Speeding accessby a contractorEnergy, science,6. Radiative Forcing ofColdRay

  8. Energy Spectrum of Cosmic-Ray Electrons at TeV Energies

    SciTech Connect (OSTI)

    Aharonian, F.; Akhperjanian, A. G.; Sahakian, V.; Barres de Almeida, U.; Chadwick, P. M.; Cheesebrough, A.; Dickinson, H. J.; Hadjichristidis, C.; Keogh, D.; McComb, T. J. L.; Nolan, S. J.; Orford, K. J.; Osborne, J. L.; Rayner, S. M.; Rulten, C. B.; Spangler, D.; Ward, M.; Bazer-Bachi, A. R.; Borrel, V.; Olive, J-F.

    2008-12-31

    The very large collection area of ground-based {gamma}-ray telescopes gives them a substantial advantage over balloon or satellite based instruments in the detection of very-high-energy (>600 GeV) cosmic-ray electrons. Here we present the electron spectrum derived from data taken with the High Energy Stereoscopic System (H.E.S.S.) of imaging atmospheric Cherenkov telescopes. In this measurement, the first of this type, we are able to extend the measurement of the electron spectrum beyond the range accessible to direct measurements. We find evidence for a substantial steepening in the energy spectrum above 600 GeV compared to lower energies.

  9. Discovery of Localized Regions of Excess 10-TeV Cosmic Rays

    E-Print Network [OSTI]

    A. A. Abdo; B. Allen; T. Aune; D. Berley; E. Blaufuss; S. Casanova; C. Chen; B. L. Dingus; R. W. Ellsworth; L. Fleysher; R. Fleysher; M. M. Gonzales; J. A. Goodman; C. M. Hoffman; P. H. Hüntemeyer; B. E. Kolterman; C. P. Lansdell; J. T. Linnemann; J. E. McEnery; A. I. Mincer; P. Nemethy; D. Noyes; J. Pretz; J. M. Ryan; P. M. Saz Parkinson; A. Shoup; G. Sinnis; A. J. Smith; G. W. Sullivan; V. Vasileiou; G. P. Walker; D. A. Williams; G. B. Yodh

    2008-10-14

    An analysis of 7 years of Milagro data performed on a 10-degree angular scale has found two localized regions of excess of unknown origin with greater than 12 sigma significance. Both regions are inconsistent with gamma-ray emission with high confidence. One of the regions has a different energy spectrum than the isotropic cosmic-ray flux at a level of 4.6 sigma, and it is consistent with hard spectrum protons with an exponential cutoff, with the most significant excess at ~10 TeV. Potential causes of these excesses are explored, but no compelling explanations are found.

  10. Discovery of Localized Regions of Excess 10-TeV Cosmic Rays

    E-Print Network [OSTI]

    Abdo, A A; Aune, T; Berley, D; Blaufuss, E; Casanova, S; Chen, C; Dingus, B L; Ellsworth, R W; Fleysher, L; Fleysher, R; Gonzales, M M; Goodman, J A; Hoffman, C M; Hüntemeyer, P H; Kolterman, B E; Lansdell, C P; Linnemann, J T; McEnery, J E; Mincer, A I; Némethy, P; Noyes, D; Pretz, J; Ryan, J M; Parkinson, P M Saz; Shoup, A; Sinnis, G; Smith, A J; Sullivan, G W; Vasileiou, V; Walker, G P; Williams, D A; Yodh, G B

    2008-01-01

    An analysis of 7 years of Milagro data performed on a 10-degree angular scale has found two localized regions of excess of unknown origin with greater than 12 sigma significance. Both regions are inconsistent with gamma-ray emission at a level of 11 sigma. One of the regions has a different energy spectrum than the isotropic cosmic-ray flux at a level of 4.6 sigma, and it is consistent with hard spectrum protons with an exponential cutoff, with the most significant excess at ~10 TeV. Potential causes of these excesses are explored, but no compelling explanations are found.

  11. Interactions of ultrahigh-energy cosmic rays with photons in the galactic center

    E-Print Network [OSTI]

    Alexander Kusenko; Jason Schissel; Floyd W. Stecker

    2005-08-04

    Ultrahigh-energy cosmic rays passing through the central region of the Galaxy interact with starlight and the infrared photons. Both nuclei and protons generate secondary fluxes of photons and neutrinos on their passage through the central region. We compute the fluxes of these secondary particles, the observations of which can be used to improve one's understanding of origin and composition of ultrahigh-energy comic rays, especially if the violation of the Greisen--Zatespin--Kuzmin cutoff is confirmed by the future data.

  12. The cosmic ray test of MRPCs for the BESIII ETOF upgrade

    E-Print Network [OSTI]

    Xiaozhuang Wang; Yuekun Heng; Zhi Wu; Cheng Li; Yongjie Sun; Hongliang Dai; Kejun Zhu; Zhenan Liu; Xiaoshan Jiang; Huayi Sheng; Shengsen Sun; Jie Zhang; Ping Cao; Weijia Sun; Siyu Wang; Xiaolu Ji; Jinzhou Zhao; Wenyuan Gong; Mei Ye; Xiaoyan Ma; Mingming Chen; Meihang Xu; Xiaolan Luo

    2015-11-29

    The upgrade of the current BESIII ETOF is carried out with the Multi-gap Resistive Plate Chamber (MRPC)technology, aiming at the overall time resolution of better than 100ps.Thecosmic ray test for the MRPC detectors, together with the new-designed electronics, including Front End Electronics (FEE), TDIG, CTTP, CLOCK and Fast Control boards, was carried out. The main purposes of cosmic ray test are checking the detectors' construction quality, testing the joint operation of the whole system and the performance of the detectors. The noise rate, time measurement are examined specifically. The results of the test indicate that the whole system works well.

  13. Tests of cosmic ray radiography for power industry applications

    E-Print Network [OSTI]

    Durham, J M; Morris, C L; Bacon, J; Fabritius, J; Fellows, S; Plaud-Ramos, K; Poulson, D; Renshaw, J

    2015-01-01

    In this report, we assess muon multiple scattering tomography as a non-destructive inspection technique in several typical areas of interest to the nuclear power industry, including monitoring concrete degradation, gate valve conditions, and pipe wall thickness. This work is motivated by the need for radiographic methods that do not require the licensing, training, and safety controls of x-rays, and by the need to be able to penetrate considerable overburden to examine internal details of components that are otherwise inaccessible, with minimum impact on industrial operations. In some scenarios, we find that muon tomography may be an attractive alternative to more typical measurements.

  14. Generalized Maximum Likelihood Method for Ultrahigh Energy Cosmic Rays

    E-Print Network [OSTI]

    Glennys R. Farrar

    2008-10-01

    The Maximum Likelihood Method is generalized to include effects important for UHECR applications. The new approach can incorporate source distance constraints implied by the observed CR energy and can allow for energy uncertainties, possible deflection in magnetic fields, multiple source types, and a spectrum of CR composition. It can be efficiently implemented and does not require the unphysical "isotropic" assumption for unidentified sources. The approach optimizes the utility of UHECR data to discriminate between source classes and can help constrain galactic and extragalactic magnetic fields. Aspects of the method are directly applicable in other contexts, such as TeV gamma ray astrophysics.

  15. The cosmic gamma-ray background in the MeV range

    E-Print Network [OSTI]

    P. Ruiz-Lapuente; M. Casse; E. Vangioni-Flam

    2000-09-20

    The $\\gamma$-ray background from supernovae is calculated on the basis of the reconstructed efficiency of supernova explosions from star formation at various redshifts. The calculations presented here show how Type Ia SN rates compatible with the results of optical supernova searches give a background emission in the MeV range that can explain the extragalactic emission measured by COMPTEL and SMM. Star formation histories reaching maximum values of 0.3-0.4 M$_{\\odot}$ yr$^{-1}$ Mpc$^{-3}$ at z$\\sim$ 1.5 (and/or possibly keeping that value to higher z) give a $\\gamma$-ray background compatible with observations while they also predict the observed supernova rates per comoving volume. The $\\gamma$-ray background in the MeV range is mostly sensitive to the star formation rate at z$\\sim$ 1-2, but the activity in forming stars at even higher z has an influence as well on the absolute level of the cosmic $\\gamma$-ray background: the time elapsed by the SNe Ia progenitors until they explode has a broad distribution and the rates of SNe Ia at z$\\sim$ 1.5-2 depend on the formation frequencies of their progenitor stars at earlier epochs. The mutual consistency of predictions of optical rates and integrated emission in the $\\gamma$-ray domain place in a firm ground the Type Ia supernova identification as the astrophysical source responsible for this cosmic background

  16. Multi-wavelength constraints on cosmic-ray leptons in the Galaxy

    E-Print Network [OSTI]

    Orlando, E; Moskalenko, I V; Dickinson, C; Digel, S; Jaffe, T R; Jóhannesson, G; Leahy, J P; Porter, T A; Vidal, M

    2015-01-01

    Cosmic rays (CRs) interact with the gas, the radiation field and the magnetic field in the Milky Way, producing diffuse emission from radio to gamma rays. Observations of this diffuse emission and comparison with detailed predictions are powerful tools to unveil the CR properties and to study CR propagation. We present various GALPROP CR propagation scenarios based on current CR measurements. The predicted synchrotron emission is compared to radio surveys, and synchrotron temperature maps from WMAP and Planck, while the predicted interstellar gamma-ray emission is compared to Fermi-LAT observations. We show how multi-wavelength observations of the Galactic diffuse emission can be used to help constrain the CR lepton spectrum and propagation. Finally we discuss how radio and microwave data could be used in understanding the diffuse Galactic gamma-ray emission observed with Fermi-LAT, especially at low energies.

  17. 30TH INTERNATIONAL COSMIC RAY CONFERENCE Search for 1-100 GeV Emission from Gamma-Ray Bursts Using Milagro

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    30TH INTERNATIONAL COSMIC RAY CONFERENCE Search for 1-100 GeV Emission from Gamma-Ray Bursts Using one hundred gamma-ray bursts (GRBs) detected since the beginning of 2000 by BATSE, BeppoSax, HETE-2 spectra of gamma-ray bursts peak around a few hundred keV, EGRET has ob- served photons in the GeV energy

  18. Probing Efficient Cosmic-Ray Acceleration in Young Supernovae

    E-Print Network [OSTI]

    Dwarkadas, Vikram V; Marcowith, A; Tatischeff, V

    2015-01-01

    The formation of a core collapse supernovae (SNe) results in a fast (but non- or mildly-relativistic) shock wave expanding outwards into the surrounding medium. The medium itself is likely modified due to the stellar mass-loss from the massive star progenitor, which may be Wolf-Rayet stars (for Type Ib/c SNe), red supergiant stars (for type IIP and perhaps IIb and IIL SNe), or some other stellar type. The wind mass-loss parameters determine the density structure of the surrounding medium. Combined with the velocity of the SN shock wave, this regulates the shock acceleration process. In this article we discuss the essential parameters that control the particle acceleration and gamma-ray emission in SNe, with particular reference to the Type IIb SN 1993J. The shock wave expanding into the high density medium leads to fast particle acceleration, giving rise to rapidly-growing plasma instabilities driven by the acceleration process itself. The instabilities grow over intraday timescales. This growth, combined wit...

  19. No 'cut off' in the High Energy Cosmic Ray Energy Spectrum

    E-Print Network [OSTI]

    Tadeusz Wibig; Arnold W. Wolfendale

    2004-08-26

    It is often claimed that there should be a 'GZK cut-off" in the flux of extragalactic cosmic rays, arising from interactions between the cosmic rays and the cosmic micro-wave background photons (e.g. 1 and 2). Some experiments (3 and 4) show particles of even higher energy than this value and this has led to claims for exotic processes (e.g. 5 and 6). We contend that such claims are unnecessary - there is no predicted cut-off, rather a continuation of the injection spectrum at reduced intensity. We have combined the world's data and shown that the prediction for a rather flat injection spectrum (exponent: 1.9 - 2.2) in the case of universal particle injection provides a reasonable fit to the data. Conventional forms for the particle attenuation in the intergalactic medium (e.g. 7 and 8) have been assumed. Either protons or iron nuclei (or a mixture) will suffice. Attention is drawn to another aspect, too, that of the losses on the infra-red radiation which may be intense near to strong sources and for sources in galaxy clusters. The attendant magnetic fields near the sources leads to significantly long diffusion times through the strong infra-red fields. Two 'case histories' are considered.

  20. Can Ultra High Energy Cosmic Rays be Evidence for New Particle Physics?

    E-Print Network [OSTI]

    Glennys R. Farrar

    1998-01-05

    Candidate astrophysical acceleration sites capable of producing the highest energy cosmic rays (E > 10^{19.5} eV) appear to be at far greater distances than is compatible with their being known particles. The properties of a new particle which can account for observations are discussed and found to be tightly constrained. In order to travel 100's or 1000's of Mpc through the cosmic microwave background radiation without severe energy loss and yet produce a shower in Earth's atmosphere which is consistent with observations, it must be a hadron with mass of order a few GeV and lifetime greater than about 1 week. A particle with the required properties was identified years ago in the context of supersymmetric theories with a very light gluino. Laboratory experiments do not exclude it, as is discussed briefly.

  1. Can ultra high energy cosmic rays be evidence for new particle physics?

    SciTech Connect (OSTI)

    Farrar, Glennys R. [Department of Physics and Astronomy Rutgers University, Piscataway, New Jersey 08855 (United States)

    1998-06-15

    Candidate astrophysical acceleration sites capable of producing the highest energy cosmic rays (E>10{sup 19.5} eV) appear to be at far greater distances than is compatible with their being known particles. The properties of a new particle which can account for observations are discussed and found to be tightly constrained. In order to travel 100's or 1000's of Mpc through the cosmic microwave background radiation without severe energy loss and yet produce a shower in Earth's atmosphere which is consistent with observations, it must be a hadron with mass of order a few GeV and lifetime greater than about 1 week. A particle with the required properties was identified years ago in the context of supersymmetric theories with a very light gluino Laboratory experiments do not exclude it, as is discussed briefly.

  2. Proc. 25th Int. Cosmic Ray Conference, Durban, 1997, OG 8.1.1 ......... Fig 6 scale corrected NUMERICAL MODELS FOR COSMIC RAY

    E-Print Network [OSTI]

    Strong, Andrew W.

    . The spatial diffusion coefficent with reacceleration assumes a Kolmogorov spectrum of weak MHD turbulence so D­dependent) diffusion, convection, while in momentum space energy loss and diffusive reacceleration are treated to take advantage of this since it must be consistent with all types of observation. We emphasize also

  3. Proc. 16th European CosmicRay Symp., 1998 (Alcala), GR1.3 1 Deciphering diffuse Galactic continuum gamma rays

    E-Print Network [OSTI]

    Strong, Andrew W.

    , Coulomb scat­ tering, bremsstrahlung, IC and synchrotron are included. A new calculation of the in. The � 0 ­decay gamma rays are calculated explicitly from the propagated proton and Helium spectra http://www.gamma.mpe--garching.mpg.de/¸aws/aws.html #12; Proc. 16th European Cosmic­Ray Symp., 1998

  4. Propagation of galactic cosmic rays in the presence of self-generated turbulence

    SciTech Connect (OSTI)

    Aloisio, Roberto; Blasi, Pasquale, E-mail: aloisio@arcetri.astro.it, E-mail: blasi@arcetri.astro.it [INAF/Osservatorio Astrofisico di Arcetri, Largo E. Fermi, 5 - 50125 Firenze (Italy)

    2013-07-01

    Cosmic rays propagating in the Galaxy may excite a streaming instability when their motion is super-alfvenic, thereby producing the conditions for their own diffusion. In this paper we present the results of a self-consistent solution of the transport equation where diffusion occurs because of the self-generated turbulence together with a pre-existing turbulence injected, for instance, by supernova explosions and cascading to smaller scales. All chemicals are included in our calculations, so that we are able to show the secondary to primary ratios in addition to the spectra of the individual elements. All predictions appear to be in good agreement with observations. The fact that data are explained with no need for artificial breaks in the injection spectrum and/or in the diffusion coefficient as functions of momentum can be interpreted as a strong indication that the phenomenon proposed here is in fact being observed in Nature. We also show that there is very good agreement between the calculated proton spectrum and the cosmic ray spectrum inferred from observations of the gamma ray emission from clouds in the Gould's belt.

  5. Cosmic rays and the magnetic field of the nearby starburst galaxy NGC 253

    E-Print Network [OSTI]

    V. Heesen; R. -J. Dettmar; M. Krause; R. Beck

    2008-01-23

    Using radio polarimetry we study the connection between the transport of cosmic rays (CR's), the three-dimensional magnetic field structure, and features of other ISM phases in the halo of NGC 253. We present a new sensitive radio continuum map of NGC 253 obtained from combined VLA and Effelsberg observations at lambda 6.2 cm. We find a prominent radio halo with a scaleheight of the thick radio disk of 1.7 kpc. The linear dependence between the local scaleheight of the vertical continuum emission and the cosmic ray electron (CRE) lifetime requires a vertical CR bulk speed of 270 km s^-1. The magnetic field structure of NGC 253 resembles an ``X''-shaped configuration where the orientation of the large-scale magnetic field is plane-parallel only in the inner regions of the disk and at small distances from the galactic midplane. At larger galactocentric radii and further away from the midplane the vertical component becomes important. This is most clearly visible at the location of the ``radio spur'' southeast of the nucleus, where the magnetic field orientation is almost vertical. We made a simple model for the dominant toroidal (r,phi) magnetic field component using a spiral magnetic field with prescribed inclination and pitch angle. The residual poloidal (r,phi,z) magnetic field component which was revealed by subtracting the model from the observations shows a distinct ``X''-shaped magnetic field orientation centered on the nucleus. The orientation angle of the poloidal magnetic field is consistent with a magnetic field transport described by the superposition of the vertical CR bulk speed and the rotation velocity. Hence, we propose a disk wind which transports cosmic rays, magnetic field, and (partially) ionized gas from the disk into the halo.

  6. Effects of turbulence on cosmic ray propagation in protostars and young star/disk systems

    SciTech Connect (OSTI)

    Fatuzzo, Marco; Adams, Fred C. E-mail: fca@umich.edu

    2014-05-20

    The magnetic fields associated with young stellar objects are expected to have an hour-glass geometry, i.e., the magnetic field lines are pinched as they thread the equatorial plane surrounding the forming star but merge smoothly onto a background field at large distances. With this field configuration, incoming cosmic rays experience both a funneling effect that acts to enhance the flux impinging on the circumstellar disk and a magnetic mirroring effect that acts to reduce that flux. To leading order, these effects nearly cancel out for simple underlying magnetic field structures. However, the environments surrounding young stellar objects are expected to be highly turbulent. This paper shows how the presence of magnetic field fluctuations affects the process of magnetic mirroring, and thereby changes the flux of cosmic rays striking circumstellar disks. Turbulence has two principle effects: (1) the (single) location of the magnetic mirror point found in the absence of turbulence is replaced with a wide distribution of values. (2) The median of the mirror point distribution moves outward for sufficiently large fluctuation amplitudes (roughly when ?B/B {sub 0} > 0.2 at the location of the turbulence-free mirror point); the distribution becomes significantly non-Gaussian in this regime as well. These results may have significant consequences for the ionization fraction of the disk, which in turn dictates the efficiency with which disk material can accrete onto the central object. A similar reduction in cosmic ray flux can occur during the earlier protostellar stages; the decrease in ionization can help alleviate the magnetic braking problem that inhibits disk formation.

  7. Modification of the parallel scattering mean free path of cosmic rays in the presence of adiabatic focusing

    SciTech Connect (OSTI)

    He, H.-Q.; Schlickeiser, R. E-mail: rsch@tp4.rub.de

    2014-09-10

    The cosmic ray mean free path in a large-scale nonuniform guide magnetic field with superposed magnetostatic turbulence is calculated to clarify some conflicting results in the literature. A new, exact integro-differential equation for the cosmic-ray anisotropy is derived from the Fokker-Planck transport equation. A perturbation analysis of this integro-differential equation leads to an analytical expression for the cosmic ray anisotropy and the focused transport equation for the isotropic part of the cosmic ray distribution function. The derived parallel spatial diffusion coefficient and the associated cosmic ray mean free path include the effect of adiabatic focusing and reduce to the standard forms in the limit of a uniform guide magnetic field. For the illustrative case of isotropic pitch angle scattering, the derived mean free path agrees with the earlier expressions of Beeck and Wibberenz, Bieber and Burger, Kota, and Litvinenko, but disagrees with the result of Shalchi. The disagreement with the expression of Shalchi is particularly strong in the limit of strong adiabatic focusing.

  8. Vibrational excitation induced by electron beam and cosmic rays in normal and superconductive aluminum bars

    E-Print Network [OSTI]

    M. Bassan; B. Buonomo; G. Cavallari; E. Coccia; S. D'Antonio; V. Fafone; L. G. Foggetta; C. Ligi; A. Marini; G. Mazzitelli; G. Modestino; G. Pizzella; L. Quintieri; F. Ronga; P. Valente; S. M. Vinko

    2011-08-02

    We report new measurements of the acoustic excitation of an Al5056 superconductive bar when hit by an electron beam, in a previously unexplored temperature range, down to 0.35 K. These data, analyzed together with previous results of the RAP experiment obtained for T > 0.54 K, show a vibrational response enhanced by a factor 4.9 with respect to that measured in the normal state. This enhancement explains the anomalous large signals due to cosmic rays previously detected in the NAUTILUS gravitational wave detector.

  9. Correlation between Compact Radio Quasars and Ultra-High Energy Cosmic Rays

    E-Print Network [OSTI]

    Glennys R. Farrar; Peter L. Biermann

    1998-06-17

    Some proposals to account for the highest energy cosmic rays predict that they should point to their sources. We study the five highest energy events (E>10^20 eV) and find they are all aligned with compact, radio-loud quasars. The probability that these alignments are coincidental is 0.005, given the accuracy of the position measurements and the rarity of such sources. The source quasars have redshifts between 0.3 and 2.2. If the correlation pointed out here is confirmed by further data, the primary must be a new hadron or one produced by a novel mechanism.

  10. Maximum Likelihood method for ultrahigh energy cosmic ray cross correlations with astrophysical sources

    E-Print Network [OSTI]

    Ronnie Jansson; Glennys R. Farrar

    2007-08-20

    We extend the Maximum Likelihood method used by HiRes to study cross correlations between a catalog of candidate astrophysical sources and Ultrahigh Energy Cosmic Rays (UHECRs), to allow for differing source luminosities. Our approach permits individual sources to be ranked according to their likelihood of having emitted the correlated UHECRs. We test both old and new method by simulations for various scenarios. We conclude that there are 9 true correlation between HiRes UHECRs and known BLLacs, with a 6*10^-5 probability of such a correlation arising by chance.

  11. Tidal disruption jets as the source of Ultra-High Energy Cosmic Rays

    E-Print Network [OSTI]

    Farrar, Glennys R

    2014-01-01

    Observations of the spectacular, blazar-like tidal disruption event (TDE) candidates Swift J1644+57 and J2058+05 show that the conditions required for accelerating protons to 10^{20} eV appear to be realized in the outer jet, and possibly in the inner jet as well. Direct and indirect estimates of the rate of jetted-TDEs, and of the energy they inject, are compatible with the observed flux of ultra-high energy cosmic rays (UHECRs) and the abundance of presently contributing sources. Thus TDE-jets can be a major source of UHECRs, even compabile with a pure proton composition.

  12. Cosmic Ray Radiography of the Damaged Cores of the Fukushima Reactors

    E-Print Network [OSTI]

    Borozdin, Konstantin; Luki?, Zarija; Milner, Edward Cas; Miyadera, Haruo; Morris, Christopher; Perry, John

    2012-01-01

    The passage of muons through matter is dominated by the Coulomb interaction with electrons and nuclei. The interaction with the electrons leads to continuous energy loss and stopping of the muons. The interaction with nuclei leads to angle diffusion. Two muon imaging methods that use flux attenuation and multiple Coulomb scattering of cosmic-ray muons are being studied as tools for diagnosing the damaged cores of the Fukushima reactors. Here we compare these two methods. We conclude that the scattering method can provide detailed information about the core. Attenuation has low contrast and little sensitivity to the core.

  13. Cosmic Ray Radiography of the Damaged Cores of the Fukushima Reactors

    E-Print Network [OSTI]

    Konstantin Borozdin; Steven Greene; Zarija Luki?; Edward Cas Milner; Haruo Miyadera; Christopher Morris; John Perry

    2012-09-13

    The passage of muons through matter is dominated by the Coulomb interaction with electrons and nuclei. The interaction with the electrons leads to continuous energy loss and stopping of the muons. The interaction with nuclei leads to angle diffusion. Two muon imaging methods that use flux attenuation and multiple Coulomb scattering of cosmic-ray muons are being studied as tools for diagnosing the damaged cores of the Fukushima reactors. Here we compare these two methods. We conclude that the scattering method can provide detailed information about the core. Attenuation has low contrast and little sensitivity to the core.

  14. Solar panels as air Cherenkov detectors for extremely high energy cosmic rays

    E-Print Network [OSTI]

    S. Cecchini; I. D'Antone; L. Degli Esposti; G. Giacomelli; M. Guerra; I. Lax; G. Mandrioli; A. Parretta; A. Sarno; R. Schioppo; M. Sorel; M. Spurio

    2000-02-07

    Increasing interest towards the observation of the highest energy cosmic rays has motivated the development of new detection techniques. The properties of the Cherenkov photon pulse emitted in the atmosphere by these very rare particles indicate low-cost semiconductor detectors as good candidates for their optical read-out. The aim of this paper is to evaluate the viability of solar panels for this purpose. The experimental framework resulting from measurements performed with suitably-designed solar cells and large conventional photovoltaic areas is presented. A discussion on the obtained and achievable sensitivities follows.

  15. Detection of the Cosmic ?-Ray Horizon From Multiwavelength Observations of Blazars

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Dominguez, A.; Finke, J. D.; Prada, F.; Primack, J. R.; Kitaura, F. S.; Siana, B.; Paneque, D.

    2013-05-24

    The first statistically significant detection of the cosmic ?-ray horizon (CGRH) that is independent of any extragalactic background light (EBL) model is presented. The CGRH is a fundamental quantity in cosmology. It gives an estimate of the opacity of the Universe to very high energy (VHE) ?-ray photons due to photon-photon pair production with the EBL. The only estimations of the CGRH to date are predictions from EBL models and lower limits from ?-ray observations of cosmological blazars and ?-ray bursts. Here, we present homogeneous synchrotron/synchrotron self-Compton (SSC) models of the spectral energy distributions of 15 blazars based on (almost) simultaneous observations from radio up to the highest energy ?-rays taken with the Fermi satellite. These synchrotron/SSC models predict the unattenuated VHE fluxes, which are compared with the observations by imaging atmospheric Cherenkov telescopes. This comparison provides an estimate of the optical depth of the EBL, which allows a derivation of the CGRH through a maximum likelihood analysis that is EBL-model independent. We find that the observed CGRH is compatible with the current knowledge of the EBL.

  16. Gamma-Ray Bursts as a Cosmic Window for Galaxy Evolution

    E-Print Network [OSTI]

    I. F. Mirabel; D. B. Sanders; E. Le Floc'h

    2000-04-03

    Present knowledge indicates that gamma-ray bursts are linked with massive stars. They will become invaluable probes of the early universe and galaxy formation. In the future, it will be possible to use gamma-ray bursts for two purposes: 1) to probe the history of massive star formation in the Universe by the rate of occurence of gamma-ray bursts, and 2) for the study of galaxy evolution at all lookback times by determining the nature of the galaxy hosts. Because gamma-rays are not attenuated by intervening dust and gas, the selection of the cosmic sites of massive star formation by this method is less affected by the biases associated with optical-uv surveys (e.g. UV-dropout techniques). Infrared and sub-millimeter follow up studies of the hosts of gamma-ray bursts may: 1) reveal a putative population of reddened ($R-K \\geq 4$) galaxies at high redshifts, and 2) detect very massive stars (population III) formed at $z \\geq$ 5.

  17. DETECTION OF THE COSMIC {gamma}-RAY HORIZON FROM MULTIWAVELENGTH OBSERVATIONS OF BLAZARS

    SciTech Connect (OSTI)

    Dominguez, A.; Siana, B. [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Finke, J. D. [U.S. Naval Research Laboratory, Space Science Division, Code 7653, 4555 Overlook Avenue SW, Washington, DC 20375 (United States); Prada, F. [Campus of International Excellence UAM-CSIC, Cantoblanco, E-28049 Madrid (Spain); Primack, J. R. [Department of Physics, University of California, Santa Cruz, CA 95064 (United States); Kitaura, F. S. [Leibniz-Institut fuer Astrophysik (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany); Paneque, D., E-mail: albertod@ucr.edu [Kavli Institute for Particle Astrophysics and Cosmology, SLAC, Stanford University, Stanford, CA 94305 (United States)

    2013-06-10

    The first statistically significant detection of the cosmic {gamma}-ray horizon (CGRH) that is independent of any extragalactic background light (EBL) model is presented. The CGRH is a fundamental quantity in cosmology. It gives an estimate of the opacity of the universe to very high energy (VHE) {gamma}-ray photons due to photon-photon pair production with the EBL. The only estimations of the CGRH to date are predictions from EBL models and lower limits from {gamma}-ray observations of cosmological blazars and {gamma}-ray bursts. Here, we present homogeneous synchrotron/synchrotron self-Compton (SSC) models of the spectral energy distributions of 15 blazars based on (almost) simultaneous observations from radio up to the highest energy {gamma}-rays taken with the Fermi satellite. These synchrotron/SSC models predict the unattenuated VHE fluxes, which are compared with the observations by imaging atmospheric Cherenkov telescopes. This comparison provides an estimate of the optical depth of the EBL, which allows us a derivation of the CGRH through a maximum likelihood analysis that is EBL-model independent. We find that the observed CGRH is compatible with the current knowledge of the EBL.

  18. Detection of the Cosmic ?-Ray Horizon From Multiwavelength Observations of Blazars

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Dominguez, A.; Finke, J. D.; Prada, F.; Primack, J. R.; Kitaura, F. S.; Siana, B.; Paneque, D.

    2013-05-24

    The first statistically significant detection of the cosmic ?-ray horizon (CGRH) that is independent of any extragalactic background light (EBL) model is presented. The CGRH is a fundamental quantity in cosmology. It gives an estimate of the opacity of the Universe to very high energy (VHE) ?-ray photons due to photon-photon pair production with the EBL. The only estimations of the CGRH to date are predictions from EBL models and lower limits from ?-ray observations of cosmological blazars and ?-ray bursts. Here, we present homogeneous synchrotron/synchrotron self-Compton (SSC) models of the spectral energy distributions of 15 blazars based on (almost)more »simultaneous observations from radio up to the highest energy ?-rays taken with the Fermi satellite. These synchrotron/SSC models predict the unattenuated VHE fluxes, which are compared with the observations by imaging atmospheric Cherenkov telescopes. This comparison provides an estimate of the optical depth of the EBL, which allows a derivation of the CGRH through a maximum likelihood analysis that is EBL-model independent. We find that the observed CGRH is compatible with the current knowledge of the EBL.« less

  19. Astrophysical Explosions: From Solar Flares to Cosmic Gamma-ray Bursts

    E-Print Network [OSTI]

    Wheeler, J Craig

    2011-01-01

    Astrophysical explosions result from the release of magnetic, gravitational, or thermonuclear energy on dynamical timescales, typically the sound-crossing time for the system. These explosions include solar and stellar flares, eruptive phenomena in accretion disks, thermonuclear combustion on the surfaces of white dwarfs and neutron stars, violent magnetic reconnection in neutron stars, thermonuclear and gravitational collapse supernovae and cosmic gamma-ray bursts, each representing a different type and amount of energy release. This paper summarizes the properties of these explosions and describes new research on thermonuclear explosions and explosions in extended circumstellar media. Parallels are drawn between studies of terrestrial and astrophysical explosions, especially the physics of the transition from deflagration to detonation. Keywords: neutron stars, black holes, supernovae, gamma-ray bursts, deflagration, detonation.

  20. Ultra high energy cosmic rays and possible signature of black strings

    E-Print Network [OSTI]

    R. C. Anjos; C. H. Coimbra-Araújo; Roldao da Rocha; V. de Souza

    2015-10-16

    Ultra high energy cosmic rays (UHECRs) probably originate in extreme conditions in which extra dimension effects might be important. In this paper we calculate the correction in black hole accretion mechanisms due to extra dimension effects in the static and rotating cases. A parametrization of the external Kerr horizons in both cases is presented and analysed. We use previous calculations of upper limits on the UHECR flux to set limits on the UHECR production efficiency of nine sources. The upper limit on the UHECR luminosity calculation is based on GeV-TeV gamma-ray measurements. The total luminosity due to the accretion mechanism is compared to the upper limit on UHECRs. The dependence of the UHECR production efficiency upper limit on black hole mass is also presented and discussed.

  1. Equipartition and Cosmic Ray Energy Densities in Central Molecular Zones of Starbursts

    E-Print Network [OSTI]

    Yoast-Hull, Tova M; Zweibel, Ellen G

    2015-01-01

    The energy densities in magnetic fields and cosmic rays (CRs) in galaxies are often assumed to be in equipartition, allowing for an indirect estimate of the magnetic field strength from the observed radio synchrotron spectrum. However, both primary and secondary CRs contribute to the synchrotron spectrum, and the CR electrons also loose energy via bremsstrahlung and inverse Compton. While classical equipartition formulae avoid these intricacies, there have been recent revisions that account for the extreme conditions in starbursts. Yet, the application of the equipartition formula to starburst environments also presupposes that timescales are long enough to reach equilibrium. Here, we test equipartition in the central molecular zones (CMZs) of nearby starburst galaxies by modeling the observed gamma-ray spectra, which provide a direct measure of the CR energy density, and the radio spectra, which provide a probe of the magnetic field strength. We find that in starbursts, the magnetic field energy density is s...

  2. Latitude survey investigation of galactic cosmic ray solar modulation during 1994-2007

    SciTech Connect (OSTI)

    Nuntiyakul, W.; Ruffolo, D.; Sáiz, A.; Evenson, P.; Bieber, J. W.; Clem, J.; Pyle, R.; Duldig, M. L.; Humble, J. E. E-mail: david.ruf@mahidol.ac.th E-mail: evenson@udel.edu E-mail: clem@bartol.udel.edu E-mail: John.Humble@utas.edu.au

    2014-11-01

    The Galactic cosmic ray spectrum exhibits subtle variations over the 22 yr solar magnetic cycle in addition to the more dramatic variations over the 11 yr sunspot cycle. Neutron monitors are large ground-based detectors that provide accurate measurements of variations in the cosmic ray flux at the top of the atmosphere above the detector. At any given location the magnetic field of the Earth excludes particles below a well-defined rigidity (momentum per unit charge) known as the cutoff rigidity, which can be accurately calculated using detailed models of the geomagnetic field. By carrying a neutron monitor to different locations, e.g., on a ship, the Earth itself serves as a magnet spectrometer. By repeating such latitude surveys with identical equipment, a sensitive measurement of changes in the spectrum can be made. In this work, we analyze data from the 1994 through 2007 series of latitude surveys conducted by the Bartol Research Institute, the University of Tasmania, and the Australian Antarctic Division. We confirm the curious 'crossover' in spectra measured near solar minima during epochs of opposite solar magnetic polarity, and show that it is directly related to a sudden change in the spectral behavior of solar modulation at the time of the polarity reversal, as revealed from contemporaneous variations in the survey data and a fixed station. We suggest that the spectral change and crossover result from the interaction of effects due to gradient/curvature drifts with a systematic change in the interplanetary diffusion coefficient caused by turbulent magnetic helicity.

  3. Cosmic Ray Velocity and Electric Charge Measurements in the AMS experiment

    E-Print Network [OSTI]

    Arruda, Luísa

    2008-01-01

    The Alpha Magnetic Spectrometer (AMS) is a particle physics detector designed to measure charged cosmic ray spectra with energies up to the TeV region and with high energy photon detection capability up to few hundred GeV. It will be installed on the International Space Station (ISS) in 2008 and will operate for more than three years. Due to its large acceptance, the flight duration and the state-of-art of particle identification techniques, AMS will have a remarkable sensitivity on antimatter and dark matter searches. The addition of different detector systems provide AMS with complementary and redundant electric charge and velocity measurements. The velocity of singly charged particles is expected to be measured with a precision of 0.1% and charge separation up to iron is attainable. The AMS capability of measuring a large range of electric charges and accurate velocities, will largely contribute to a better understanding of cosmic ray production, acceleration and propagation mechanisms in the galaxy.

  4. Cosmic Ray Velocity and Electric Charge Measurements in the AMS experiment

    E-Print Network [OSTI]

    AMS Collaboration; Luísa Arruda

    2008-01-30

    The Alpha Magnetic Spectrometer (AMS) is a particle physics detector designed to measure charged cosmic ray spectra with energies up to the TeV region and with high energy photon detection capability up to few hundred GeV. It will be installed on the International Space Station (ISS) in 2008 and will operate for more than three years. Due to its large acceptance, the flight duration and the state-of-art of particle identification techniques, AMS will have a remarkable sensitivity on antimatter and dark matter searches. The addition of different detector systems provide AMS with complementary and redundant electric charge and velocity measurements. The velocity of singly charged particles is expected to be measured with a precision of 0.1% and charge separation up to iron is attainable. The AMS capability of measuring a large range of electric charges and accurate velocities, will largely contribute to a better understanding of cosmic ray production, acceleration and propagation mechanisms in the galaxy.

  5. The origin of all cosmic rays : a space-filling mechanism.

    SciTech Connect (OSTI)

    Colgate, S. A.; Li, H.

    2001-01-01

    There is a need for one mechanism to accelerate cosmic rays universally over the full energy spectrum, isotropically, and space filling. The current view is a theory based upon a series of mechanisms, patched to fit various spectral regions with a mechanism for the origin of the UHCRs still in doubt. We suggest that the reconnection of force-free magnetic fields produced by the twisting of all imbedded magnetic flux by the vorticity motion of all accretion or condensations both within the Galaxy as well as the metagalaxy is the universal mechanism. This leads to the acceleration of all cosmic rays with both total energy and individual energies up to the highest observed of 3 x 10{sup 20} ev and predicting an upper limit of 10{sup 23} ev. There are three primary, and we believe compelling reasons for adopting this different view of the origin of CRs. (1) The energy source is space filling and isotropic, thereby avoiding any anisotropy's due to single sources, e.g., supernovae remnants and AGN. (2) The galactic and particularly the extragalactic energy source is sufficient to supply the full energy of a universal galactic and extragalactic spectrum of 10{sup 60} to 10{sup 61} ergs sufficient to avoid the GZK cut-off. (3) Efficient E{sub parallel} acceleration from reconnection of force-free fields is well observed in the laboratory whereas collisionless shock acceleration still eludes laboratory confirmation.

  6. CONSTRAINTS ON THE SOURCE OF ULTRA-HIGH-ENERGY COSMIC RAYS USING ANISOTROPY VERSUS CHEMICAL COMPOSITION

    SciTech Connect (OSTI)

    Liu, Ruo-Yu; Wang, Xiang-Yu [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Taylor, Andrew M. [Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin 2 (Ireland); Lemoine, Martin [Institut d'Astrophysique de Paris, CNRS, UPMC, 98 bis Boulevard Arago, F-75014 Paris (France); Waxman, Eli, E-mail: lemoine@iap.fr [Physics Faculty, Weizmann Institute, P.O. Box 26, Rehovot 7600 (Israel)

    2013-10-20

    The joint analysis of anisotropy signals and chemical composition of ultra-high-energy cosmic rays offers strong potential for shedding light on the sources of these particles. Following up on an earlier idea, this paper studies the anisotropies produced by protons of energy >E/Z, assuming that anisotropies at energy >E have been produced by nuclei of charge Z, which share the same magnetic rigidity. We calculate the number of secondary protons produced through photodisintegration of the primary heavy nuclei. Making the extreme assumption that the source does not inject any proton, we find that the source(s) responsible for anisotropies such as reported by the Pierre Auger Observatory should lie closer than ?20-30, 80-100, and 180-200 Mpc if the anisotropy signal is mainly composed of oxygen, silicon, and iron nuclei, respectively. A violation of this constraint would otherwise result in the secondary protons forming a more significant anisotropy signal at lower energies. Even if the source were located closer than this distance, it would require an extraordinary metallicity ?> 120, 1600, and 1100 times solar metallicity in the acceleration zone of the source, for oxygen, silicon, and iron, respectively, to ensure that the concomitantly injected protons do not produce a more significant low-energy anisotropy. This offers interesting prospects for constraining the nature and the source of ultra-high-energy cosmic rays with the increase in statistics expected from next-generation detectors.

  7. Cosmic rays and the magnetic field of the nearby starburst galaxy NGC 253

    E-Print Network [OSTI]

    Heesen, V; Krause, M; Beck, R

    2008-01-01

    Using radio polarimetry we study the connection between the transport of cosmic rays (CR's), the three-dimensional magnetic field structure, and features of other ISM phases in the halo of NGC 253. We present a new sensitive radio continuum map of NGC 253 obtained from combined VLA and Effelsberg observations at lambda 6.2 cm. We find a prominent radio halo with a scaleheight of the thick radio disk of 1.7 kpc. The linear dependence between the local scaleheight of the vertical continuum emission and the cosmic ray electron (CRE) lifetime requires a vertical CR bulk speed of 270 km s^-1. The magnetic field structure of NGC 253 resembles an ``X''-shaped configuration where the orientation of the large-scale magnetic field is plane-parallel only in the inner regions of the disk and at small distances from the galactic midplane. At larger galactocentric radii and further away from the midplane the vertical component becomes important. This is most clearly visible at the location of the ``radio spur'' southeast o...

  8. The Large Scale Cosmic-Ray Anisotropy as Observed with Milagro

    E-Print Network [OSTI]

    A. A. Abdo; B. T. Allen; T. Aune; D. Berley; S. Casanova; C. Chen; B. L. Dingus; R. W. Ellsworth; L. Fleysher; R. Fleysher; M. M. Gonzalez; J. A. Goodman; C. M. Hoffman; B. Hopper; P. H. Hüntemeyer; B. E. Kolterman; C. P. Lansdell; J. T. Linnemann; J. E. McEnery; A. I. Mincer; P. Nemethy; D. Noyes; J. Pretz; J. M. Ryan; P. M. Saz Parkinson; A. Shoup; G. Sinnis; A. J. Smith; G. W. Sullivan; V. Vasileiou; G. P. Walker; D. A. Williams; G. B. Yodh

    2009-04-20

    Results are presented of a harmonic analysis of the large scale cosmic-ray anisotropy as observed by the Milagro observatory. We show a two-dimensional display of the sidereal anisotropy pro jections in right ascension generated by the fitting of three harmonics to 18 separate declination bands. The Milagro observatory is a water Cherenkov detector located in the Jemez mountains near Los Alamos, New Mexico. With a high duty cycle and large field-of-view, Milagro is an excellent instrument for measuring this anisotropy with high sensitivity at TeV energies. The analysis is conducted using a seven year data sample consisting of more than 95 billion events, the largest such data set in existence. We observe an anisotropy with a magnitude around 0.1% for cosmic rays with a median energy of 6 TeV. The dominant feature is a deficit region of depth (2.49 +/- 0.02 stat. +/- 0.09 sys.)x10^(-3) in the direction of the Galactic North Pole centered at 189 degrees right ascension. We observe a steady increase in the magnitude of the signal over seven years.

  9. The Large Scale Cosmic-Ray Anisotropy as Observed with Milagro

    E-Print Network [OSTI]

    Abdo, A A; Aune, T; Berley, D; Casanova, S; Chen, C; Dingus, B L; Ellsworth, R W; Fleysher, L; Fleysher, R; González, M M; Goodman, J A; Hoffman, C M; Hopper, B; Hüntemeyer, P H; Kolterman, B E; Lansdell, C P; Linnemann, J T; McEnery, J E; Mincer, A I; Némethy, P; Noyes, D; Ryan, J M; Parkinson, P M Saz; Shoup, A; Sinnis, G; Smith, A J; Sullivan, G W; Vasileiou, V; Walker, G P; Williams, D A; Yodh, G B

    2008-01-01

    Results are presented of a harmonic analysis of the large scale cosmic-ray anisotropy as observed by the Milagro observatory. We show a two-dimensional display of the sidereal anisotropy projections in right ascension generated by the fitting of three harmonics to 18 separate declination bands. The Milagro observatory is a water Cherenkov detector located in the Jemez mountains near Los Alamos, New Mexico. With a high duty cycle and large field-of-view, Milagro is an excellent instrument for measuring this anisotropy with high sensitivity at TeV energies. The analysis is conducted using a seven year data sample consisting of more than 95 billion events. We observe an anisotropy with a magnitude around 0.1% for cosmic rays with a median energy of 6 TeV. The dominant feature is a deficit region of depth (-2.85 +/- 0.06 stat. +/- 0.08 syst.)x10^(-3) in the direction of the Galactic North Pole with a range in declination of -10 to 45 degrees and 150 to 225 degrees in right ascension. We observe a steady increase ...

  10. Sensitivity of full-sky experiments to large scale cosmic ray anisotropies

    E-Print Network [OSTI]

    Denton, Peter B

    2015-01-01

    The two main advantages of space-based observation of extreme energy ($\\gtrsim5\\times10^{19}$ eV) cosmic rays (EECRs) over ground based observatories are the increased field of view and the full-sky coverage with nearly uniform systematics across the entire sky. The former guarantees increased statistics, whereas the latter enables a clean partitioning of the sky into spherical harmonics. The discovery of anisotropies would help to identify the long sought origin of EECRs. We begin an investigation of the reach of a full-sky space-based experiment such as EUSO to detect anisotropies in the extreme-energy cosmic-ray sky compared to ground based partial-sky experiments such as the Pierre Auger Observatory and Telescope Array. The technique is explained here, and simulations for a Universe with just two nonzero multipoles, monopole plus either dipole or quadrupole, are presented. These simulations quantify the advantages of space-based, all-sky coverage.

  11. Implications to Sources of Ultra-high-energy Cosmic Rays from their Arrival Distribution

    E-Print Network [OSTI]

    Hajime Takami; Katsuhiko Sato

    2008-07-22

    We estimate the local number density of sources of ultra-high-energy cosmic rays (UHECRs) based on the statistical features of their arrival direction distribution. We calculate the arrival distributions of protons above $10^{19}$ eV taking into account their propagation process in the Galactic magnetic field and a structured intergalactic magnetic field, and statistically compare those with the observational result of the Pierre Auger Observatory. The anisotropy in the arrival distribution at the highest energies enables us to estimate the number density of UHECR sources as $\\sim 10^{-4} {\\rm Mpc}^{-3}$ assuming the persistent activity of UHECR sources. We compare the estimated number density of UHECR sources with the number densities of known astrophysical objects. This estimated number density is consistent with the number density of Fanaroff-Reily I galaxies. We also discuss the reproducability of the observed {\\it isotropy} in the arrival distribution above $10^{19}$ eV. We find that the estimated source model cannot reproduce the observed isotropy. However, the observed isotropy can be reproduced with the number density of $10^{-2}$-$10^{-3} {\\rm Mpc}^{-3}$. This fact indicates the existence of UHECR sources with a maximum acceleration energy of $\\sim 10^{19}$ eV whose number density is an order of magnitude more than that injecting the highest energy cosmic rays.

  12. NA61-SHINE: Hadron Production Measurements for Cosmic Ray and Neutrino Experiments

    E-Print Network [OSTI]

    Nicolas Abgrall

    2010-05-25

    As neutrino long baseline experiments enter a new domain of precision, important systematic errors due to poor knowledge of production cross-sections for pions and kaons require more dedicated measurements for precise neutrino flux predictions. The cosmic ray experiments require dedicated hadron production measurements to tune simulation models used to describe air shower profiles. Among other goals, the NA61-SHINE (SPS Heavy Ion and Neutrino Experiment) experiment at the CERN SPS aims at precision measurements (5% and below) for both neutrino and cosmic ray experiments: those will improve the prediction of the neutrino flux for the T2K experiment at J-PARC and the prediction of muon production in the propagation of air showers for the Auger and KASCADE experiments. Motivations for new hadron production measurements are briefly discussed. NA61-SHINE took data during a pilot run in 2007 and in 2009 with different Carbon targets. The NA61-SHINE setup and preliminary spectra for positive and negative pions obtained with the 2007 thin (4% interaction length) Carbon target data are presented. The use of the NA61 data for the T2K neutrino flux predictions is finally discussed in further details.

  13. STABILITY OF COSMIC-RAY MODIFIED SHOCKS: TWO-FLUID APPROACH

    SciTech Connect (OSTI)

    Saito, Tatsuhiko; Hoshino, Masahiro; Amano, Takanobu

    2013-10-01

    The stability of cosmic-ray modified shocks (CRMSs) is studied by means of numerical simulations. Owing to the nonlinear feedback of cosmic-ray (CR) acceleration, a downstream state of the modified shock can no longer be uniquely determined for given upstream parameters. It is known that up to three distinct solutions exist, which are characterized by CR production efficiency as the 'efficient', 'intermediate', and 'inefficient' branches. The stability of these solutions is investigated by performing direct time-dependent simulations of a two-fluid model. It is found that both the efficient and inefficient branches are stable even against a large-amplitude perturbation, while the intermediate one is always unstable and evolves into the inefficient state as a result of nonlinear time development. This bistable feature is robust in a wide range of parameters and does not depend on the injection model. Fully nonlinear time evolution of a hydrodynamic shock with injection results in the least efficient state in terms of CR production, consistent with the bistable feature. This suggests that the CR production efficiency in supernova remnant shocks may be lower than previously discussed in the framework of the nonlinear shock acceleration theory considering the efficient solution of the CRMS.

  14. Cosmic ray electrons, positrons and the synchrotron emission of the Galaxy: consistent analysis and implications

    SciTech Connect (OSTI)

    Bernardo, Giuseppe Di [Department of Physics, University of Gothenburg, SE 412 96 Gothenburg (Sweden); Evoli, Carmelo [II. Institut für Theoretische Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany); Gaggero, Daniele [SISSA, Via Bonomea 265, 34136 Trieste (Italy); Grasso, Dario [Dipartimento di Fisica, Universitŕ di Siena, Via Roma 56, I-56100 Siena (Italy); Maccione, Luca, E-mail: giuseppe.dibernardo@physics.gu.se, E-mail: carmelo.evoli@desy.de, E-mail: dgaggero@sissa.it, E-mail: dario.grasso@pi.infn.it, E-mail: luca.maccione@lmu.de [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, D-80805 München (Germany)

    2013-03-01

    A multichannel analysis of cosmic ray electron and positron spectra and of the diffuse synchrotron emission of the Galaxy is performed by using the DRAGON code. This study is aimed at probing the interstellar electron source spectrum down to E ?< 1GeV and at constraining several propagation parameters. We find that above 4GeV the e{sup ?} source spectrum is compatible with a power-law of index ? 2.5. Below 4GeV instead it must be significantly suppressed and the total lepton spectrum is dominated by secondary particles. The positron spectrum and fraction measured below a few GeV are consistently reproduced only within low reacceleration models. We also constrain the scale-height z{sub t} of the cosmic-ray distribution using three independent (and, in two cases, original) arguments, showing that values of z{sub t} ?< 2kpc are excluded. This result may have strong implications for particle dark matter searches.

  15. The Pierre Auger Observatory scaler mode for the study of solar activity modulation of galactic cosmic rays

    SciTech Connect (OSTI)

    Abreu, P.; Aglietta, M.; Ahn, E.J.; Allard, D.; Allekotte, I.; Allen, J.; Alvarez Castillo, J.; Alvarez-Muniz, J.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; /Wisconsin U., Milwaukee /Lisbon, LIFEP /Lisbon, IST

    2011-01-01

    Since data-taking began in January 2004, the Pierre Auger Observatory has been recording the count rates of low energy secondary cosmic ray particles for the self-calibration of the ground detectors of its surface detector array. After correcting for atmospheric effects, modulations of galactic cosmic rays due to solar activity and transient events are observed. Temporal variations related with the activity of the heliosphere can be determined with high accuracy due to the high total count rates. In this study, the available data are presented together with an analysis focused on the observation of Forbush decreases, where a strong correlation with neutron monitor data is found.

  16. THE ULTRA HIGH ENERGY COSMIC RAY SPECTRUM G.L. Cassiday, R. Cooper, S. C. Corbato, B. R. Dawson, J.W. Elbert,

    E-Print Network [OSTI]

    OG 6.3-5 THE ULTRA HIGH ENERGY COSMIC RAY SPECTRUM G.L. Cassiday, R. Cooper, S. C. Corbato, B. R We will update the differential cosmic ray spectrum above 0.3 EeV obtained from the Fly's Eye detector data. Preliminary results support previously published data of no events with primary energy above

  17. 30TH INTERNATIONAL COSMIC RAY CONFERENCE Gamma-ray albedo of the moon

    E-Print Network [OSTI]

    Moskalenko, Igor V.

    of CR proton and helium spectra by the Payload for Antimatter Matter Exploration and Light]; low energy -ray spectroscopy data ac- quired by the Lunar Prospector were used to map the elemental

  18. Chandra X-ray Observations of Pictor A: High Energy Cosmic Rays in a Radio Galaxy?

    E-Print Network [OSTI]

    A. S. Wilson; A. J. Young; P. L. Shopbell

    2000-10-13

    We report X-ray observations of the nearby, powerful radio galaxy Pictor A with the Chandra Observatory and optical and near uv observations of its western radio hot spot with the Hubble Space Telescope. X-ray emission is detected from the nucleus, a 1.9 arcmin (110 kpc) long jet to the west of the nucleus, the western radio hot spot some 4.2 arcmin (240 kpc) from the nucleus, and the eastern radio lobe. The morphology of the western hot spot is remarkably similar to that seen at radio and optical wavelengths, where the emission is known to be synchrotron radiation. The X-ray spectrum of the hot spot is well described by an absorbed power law with photon index \\Gamma = 2.07 (+/- 0.11). The X-ray jet coincides with a weak radio jet and is laterally extended by \\simeq 2.0 arcsec (1.9 kpc). The observed jet is up to \\simeq 15 times brighter in X-rays than any counter jet, a difference ascribed to relativistic boosting as the western radio lobe is probably the closer. The jet's spectrum is well modelled by an absorbed power law with \\Gamma = 1.94 (+0.43/-0.49) and poorly fitted by a Raymond-Smith thermal plasma model. (Abstract truncated).

  19. DIFFUSE GALACTIC CONTINUUM GAMMA RAYS: A MODEL COMPATIBLE WITH EGRET DATA AND COSMIC-RAY MEASUREMENTS

    E-Print Network [OSTI]

    Moskalenko, Igor V.

    Garching, Germany; aws@mpe.mpg.de Igor V. Moskalenko1 NASA Goddard Space Flight Center, Code 661, Greenbelt. In particular, the spectrum of -rays calculated under the assumption that the proton and electron spectra -production in p-p interactions. However, a calculation made using modern Monte Carlo event generators

  20. Kolmogorov-Smirnov test as a tool to study the distribution of ultra-high energy cosmic ray sources

    E-Print Network [OSTI]

    Diego Harari; Silvia Mollerach; Esteban Roulet

    2008-10-31

    We analyze in detail the two-dimensional Kolmogorov-Smirnov test as a tool to learn about the distribution of the sources of the ultra-high energy cosmic rays. We confront in particular models based on AGN observed in X rays, on galaxies observed in HI and isotropic distributions, discussing how this method can be used not only to reject isotropy but also to support or reject specific source models, extending results obtained recently in the literature.

  1. Cosmic-Ray Models of the Ridge-Like Excess of Gamma Rays in the Galactic Center

    E-Print Network [OSTI]

    Oscar Macias; Chris Gordon; Roland Crocker; Stefano Profumo

    2015-06-11

    The High-Energy Stereoscopic System (HESS) has detected diffuse TeV emission correlated with the distribution of molecular gas along the Ridge at the Galactic Center. Diffuse, non-thermal emission is also seen by the Fermi large area telescope (Fermi-LAT) in the GeV range and by radio telescopes in the GHz range. Additionally, there is a distinct, spherically symmetric excess of gamma rays seen by Fermi-LAT in the GeV range. A cosmic ray flare, occurring in the Galactic Center, $10^4$ years ago has been proposed to explain the TeV Ridge. An alternative, steady-state model explaining all three data sets (TeV, GeV, and radio) invokes purely leptonic processes. We show that the flare model from the Galactic Center also provides an acceptable fit to the GeV and radio data, provided the diffusion coefficient is energy independent. However, if Kolmogorov-type turbulence is assumed for the diffusion coefficient, we find that two flares are needed, one for the TeV data (occurring approximately $10^4 $ years ago) and an older one for the GeV data (approximately $10^5$ years old). We find that the flare models we investigate do not fit the spherically symmetric GeV excess as well as the usual generalized Navarro-Frenk-White spatial profile, but are better suited to explaining the Ridge. We also show that a range of single-zone, steady-state models are able to explain all three spectral data sets. Large gas densities equal to the volumetric average in the region can be accommodated by an energy independent diffusion or streaming based steady-state model. Additionally, we investigate how the flare and steady-state models may be distinguished with future gamma-ray data looking for a spatial dependence of the gamma-ray spectral index.

  2. 30TH INTERNATIONAL COSMIC RAY CONFERENCE A Study of the In-Orbit Particle Rate with the PAMELA Anticoincidence System

    E-Print Network [OSTI]

    Morselli, Aldo

    × 600 km) orbit. The PAMELA apparatus consists of a permanent magnet silicon spectrometer]. PAMELA is a powerful particle identifier consist- ing of a permanent magnet spectrometer, an elec to the investigation of dark matter, the baryon asymmetry in the Universe, cosmic ray generation and propa- gation

  3. Average mass composition of primary cosmic rays in the superhigh energy region by Yakutsk complex EAS array data

    E-Print Network [OSTI]

    S. P. Knurenko; A. A. Ivanov; A. V. Sabourov; I. Ye. Sleptsov

    2007-11-19

    The characteristics relating to the lateral and longitudinal development of EAS in the energy region of 10^15-10^19eV have been analyzed in the framework of the QGSJET model and of mass composition of primary cosmic rays. It is found that at E(0) >= 5*10^15eV the mean mass composition of primary cosmic rays begins to vary as indicated by a rise of with increasing energy. The maximum value of is observed at E(0) ~ (5-50)*10^16eV. It is confirmed by data of many compact EAS arrays and does not contradict an anomalous diffusion model of cosmic ray propagation in our Galaxy. In the superhigh energy region (>=10^18eV) the value begins to decrease, i.e. the mass composition becomes lighter and consists of protons and nuclei of He and C. It does not contradict our earlier estimations for the mass composition and points to a growing role of the metagalactic component of cosmic rays in the superhigh energy region.

  4. Fractions of proton, helium, middle and heavy nuclei in primary cosmic rays at energy 10**16eV

    E-Print Network [OSTI]

    Maia Kalmakhelidze; Nina Roinishvili; Manana Svanidze

    2001-07-06

    Classification of gamma-hadron families, registered by the Pamir collaboration, on four groups of nuclei (P, He, middle and heavy), responsible for their generation, is made, and fractions of families in each of the groups are estimated. Results show, that below the knee of the energy spectrum the chemical composition of primary cosmic rays remains close to the normal one.

  5. Suprathermal particle addition to solar wind pressure: possible influence on magnetospheric transmissivity of low energy cosmic rays?

    E-Print Network [OSTI]

    Bobik, P; Consolandi, C; Della Torre, S; Gervasi, M; Grandi, D; Kudela, K; La Vacca, G; Mallamaci, M; Pensotti, S; Rancoita, P G; Rozza, D; Tacconi, M

    2013-01-01

    Energetic (suprathermal) solar particles, accelerated in the interplanetary medium, contribute to the solar wind pressure, in particular during high solar activity periods. We estimated the effect of the increase of solar wind pressure due to suprathermal particles on magnetospheric transmissivity of galactic cosmic rays in the case of one recent solar event.

  6. Measurement of the Flux of Ultrahigh Energy Cosmic Rays from Monocular Observations by the High Resolution Fly's Eye

    E-Print Network [OSTI]

    of Physics and Nevis Laboratory, New York, New York, USA 6) University of New Mexico, Department of PhysicsMeasurement of the Flux of Ultrahigh Energy Cosmic Rays from Monocular Observations by the High of Utah, Department of Physics and High Energy Astrophysics Institute, Salt Lake City, Utah, USA 2

  7. Model-dependent estimate on the connection between fast radio bursts and ultra high energy cosmic rays

    SciTech Connect (OSTI)

    Li, Xiang; Zhou, Bei; He, Hao-Ning; Fan, Yi-Zhong; Wei, Da-Ming, E-mail: yzfan@pmo.ac.cn [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Science, Nanjing 210008 (China)

    2014-12-10

    The existence of fast radio bursts (FRBs), a new type of extragalatic transient, has recently been established, and quite a few models have been proposed. In this work, we discuss the possible connection between the FRB sources and ultra high energy (>10{sup 18} eV) cosmic rays. We show that in the blitzar model and the model of merging binary neutron stars, which includes the huge energy release of each FRB central engine together with the rather high rate of FRBs, the accelerated EeV cosmic rays may contribute significantly to the observed ones. In other FRB models, including, for example, the merger of double white dwarfs and the energetic magnetar radio flares, no significant EeV cosmic ray is expected. We also suggest that the mergers of double neutron stars, even if they are irrelevant to FRBs, may play a nonignorable role in producing EeV cosmic ray protons if supramassive neutron stars are formed in a sufficient fraction of mergers and the merger rate is ? 10{sup 3} yr{sup –1} Gpc{sup –3}. Such a possibility will be unambiguously tested in the era of gravitational wave astronomy.

  8. Place Conference Title, Location, and Dates Here 1 Cosmic Rays in the PeV Energy Range: KASCADE-Grande

    E-Print Network [OSTI]

    Hörandel, Jörg R.

    of new hadronic interaction mechanisms at the knee energy, as for example the production of heavyPlace Conference Title, Location, and Dates Here 1 Cosmic Rays in the PeV Energy Range: KASCADE, Forschungszentrum Karlsruhe, 76021 Karlsruhe, Germany T. Antoni, J.R. H¨orandel, M. Roth, M. St¨umpert Institut f

  9. 30TH INTERNATIONAL COSMIC RAY CONFERENCE Observation of the GZK Cutoff by the HiRes Experiment

    E-Print Network [OSTI]

    light measured composition, is at just the right energy to be caused by the GZK energy loss mechanism observed the GZK cutoff. HiRes observes two separate features in the ultra-high energy cosmic ray (UHECR) energy spectrum: a hardening of the spectrum, the ankle, at an energy of 4 × 1018 eV, and a sharp

  10. Proceedings of ICRC 2001: 1 cCopernicus Gesellschaft 2001 The Evolution of Galactic Cosmic Ray Element Spectra from Solar

    E-Print Network [OSTI]

    Davis, Andrew J.

    behind 5 gcm ľ of shielding at solar minimum (data from Wilson et al., 1997). mission lasting a year of solar modulation. Depending on the applicable radiation limits, these uncertainties in the radiation Cosmic Ray Element Spectra from Solar Minimum to Solar Maximum: ACE Measurements A. J. Davis1 , R. A

  11. Fast Neutron - Mirror Neutron Oscillation and Ultra High Energy Cosmic Rays

    E-Print Network [OSTI]

    Zurab Berezhiani; Luis Bento

    2006-02-24

    If there exists the mirror world, a parallel hidden sector of particles with exactly the same microphysics as that of the observable particles, then the primordial nucleosynthesis constraints require that the temperature of the cosmic background of mirror relic photons should be smaller than that of the ordinary relic photons, T'/T neutron - mirror neutron oscillation in vacuum, with an oscillation time $\\tau \\sim 1$ s, much smaller than the neutron lifetime. We show that this could provide a very efficient mechanism for transporting ultra high energy protons at large cosmological distances. The mechanism operates as follows: a super-GZK energy proton scatters a relic photon producing a neutron that oscillates into a mirror neutron which then decays into a mirror proton. The latter undergoes a symmetric process, scattering a mirror relic photon and producing back an ordinary nucleon, but only after traveling a distance $(T/T')^{3}$ times larger than ordinary protons. This may relax or completely remove the GZK-cutoff in the cosmic ray spectrum and also explain the correlation between the observed ultra high energy protons and far distant sources as are the BL Lacs.

  12. Probing the Cosmic Star Formation History by Brightness Distribution of Gamma-Ray Bursts

    E-Print Network [OSTI]

    Tomonori Totani

    1998-08-20

    Brightness distribution of Gamma-Ray Bursts (GRBs) is studied in detail under the assumption that GRB rate is related to cosmic star formation rate. The two populations of the long- and short-duration bursts in the 4B BATSE catalog are analyzed separately. Taking account of current uncertainties in the observational estimate of star formation rate (SFR), we have tried various models of the cosmic star formation history and we find that the SFR evolution in $z$ = 0--1 is strongly constrained by the GRB distribution if the standard candle approximation is valid. The strong SFR evolution by a factor of $\\sim$ 15 from $z$ = 0 to 1 inferred from UV observations is too steep to be consistent with the GRB distribution for any distance scale of GRBs. Some possibilities to reconcile this discrepancy are discussed, including the intrinsic luminosity dispersion of GRBs and/or modification of star formation history estimated by UV observations. We argue that SFR increase factor from $z$ = 0 to 1 may be as low as about 4 if we choose different sets of cosmological parameters and/or take account of the evolution of metallicity and dust extinction in the UV data, and this would significantly remedy the discrepancy.

  13. Proton-air cross section measurement with the ARGO-YBJ cosmic ray experiment

    E-Print Network [OSTI]

    The ARGO-YBJ Collaboration

    2009-04-27

    The proton-air cross section in the energy range 1-100 TeV has been measured by the ARGO-YBJ cosmic ray experiment. The analysis is based on the flux attenuation for different atmospheric depths (i.e. zenith angles) and exploits the detector capabilities of selecting the shower development stage by means of hit multiplicity, density and lateral profile measurements at ground. The effects of shower fluctuations, the contribution of heavier primaries and the uncertainties of the hadronic interaction models, have been taken into account. The results have been used to estimate the total proton-proton cross section at center of mass energies between 70 and 500 GeV, where no accelerator data are currently available.

  14. Ultrahigh-energy cosmic-ray bounds on nonbirefringent modified Maxwell theory

    SciTech Connect (OSTI)

    Klinkhamer, F. R.; Risse, M.

    2008-01-01

    A particularly simple Lorentz-violating modification of the Maxwell theory of photons maintains gauge invariance, CPT, and renormalization. This modified Maxwell theory, coupled to standard Dirac particles, involves 19 dimensionless 'deformation parameters'. Ten of these parameters lead to birefringence and are already tightly constrained by astrophysics. New bounds on the remaining nine nonbirefringent parameters can be obtained from the absence of vacuum Cherenkov radiation for ultrahigh-energy cosmic rays (UHECRs). Using selected UHECR events recorded at the Pierre Auger Observatory and assigning pseudorandom directions (i.e., assuming large-scale isotropy), Cherenkov bounds are found at the 10{sup -18} level, which improve considerably upon current laboratory bounds. Future UHECR observations may reduce these Cherenkov bounds to the 10{sup -23} level.

  15. Foreground and Source of a Cluster of Ultra-high Energy Cosmic Rays

    E-Print Network [OSTI]

    Glennys R. Farrar; Andreas A. Berlind; David W. Hogg

    2005-07-28

    We investigate the origin of a nearly pointlike cluster of 5 ultrahigh energy cosmic rays at RA ~169.2deg and dec ~56.8deg, using Sloan Digital Sky Survey and other data. No particular source candidates are found near the estimated source direction, but the direction is exceptional in having a likely merging pair of galaxy clusters at 140/h Mpc, with an unusually low foreground density. Large scale shocks or another product of the merging galaxy clusters may accelerate the UHECRs, or the merging galaxy clusters may be coincidental and the UHECRs may be accelerated in a rare event of an unexceptional progenitor. Low magnetic deflections in the foreground void may explain why this is the only identified pointlike cluster of so many UHECRs.

  16. AMS-02 data confronts acceleration of cosmic ray secondaries in nearby sources

    E-Print Network [OSTI]

    Mertsch, Philipp

    2014-01-01

    We revisit the model proposed earlier to account for the observed increase in the positron fraction in cosmic rays with increasing energy, in the light of new data from the Alpha Magnetic Spectrometer (AMS-02) experiment. The model accounts for the production and acceleration of secondary electrons and positrons in nearby supernova remnants which results in an additional, harder component that becomes dominant at high energies. By fitting this to AMS-02 data we can calculate the expected concomitant rise of the boron-to-carbon ratio, as well as of the fraction of antiprotons. If these predictions are confirmed by the forthcoming AMS-02 data it would conclusively rule out all other proposed explanations.

  17. Low energy cosmic ray positron fraction explained by charge-sign dependent solar modulation

    E-Print Network [OSTI]

    Luca Maccione

    2013-01-24

    We compute cosmic ray (CR) nuclei, proton, antiproton, electron and positron spectra below 1 TeV at Earth by means of a detailed transport description in the galaxy and in the solar system. CR spectra below 10 GeV are strongly modified by charge-sign dependent propagation effects. These depend on the polarity of the solar magnetic field and therefore vary with the solar cycle. The puzzling discrepancy between the low-energy positron fraction measured by PAMELA and AMS-01 is then easily explained by their different data-taking epochs. We reproduce the observed spectra of CR light nuclei within the same galactic and solar-system propagation model.

  18. Studies of Cosmic Ray Composition and Air Shower Structure with the Pierre Auger Observatory

    SciTech Connect (OSTI)

    Abraham, : J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Ahn, E.J.; Allard, D.; Allekotte, I.; Allen, J.; Alvarez-Muniz, J.; Ambrosio, M.; Anchordoqui, L.

    2009-06-01

    These are presentations to be presented at the 31st International Cosmic Ray Conference, in Lodz, Poland during July 2009. It consists of the following presentations: (1) Measurement of the average depth of shower maximum and its fluctuations with the Pierre Auger Observatory; (2) Study of the nuclear mass composition of UHECR with the surface detectors of the Pierre Auger Observatory; (3) Comparison of data from the Pierre Auger Observatory with predictions from air shower simulations: testing models of hadronic interactions; (4) A Monte Carlo exploration of methods to determine the UHECR composition with the Pierre Auger Observatory; (5) The delay of the start-time measured with the Pierre Auger Observatory for inclined showers and a comparison of its variance with models; (6) UHE neutrino signatures in the surface detector of the Pierre Auger Observatory; and (7) The electromagnetic component of inclined air showers at the Pierre Auger Observatory.

  19. Assessing the Feasibility of Interrogating Nuclear Waste Storage Silos using Cosmic-ray Muons

    E-Print Network [OSTI]

    Ambrosino, F; Cimmino, L; D'Alessandro, R; Ireland, D G; Kaiser, R; Mahon, D F; Mori, N; Noli, P; Saracino, G; Shearer, C; Viliani, L; Yang, G

    2014-01-01

    Muon radiography is a fast growing field in applied scientific research. In recent years, many detector technologies and imaging techniques using the Coulomb scattering and absorption properties of cosmic-ray muons have been developed for the non-destructive assay of various structures across a wide range of applications. This work presents the first results that assess the feasibility of using muons to interrogate waste silos within the UK Nuclear Industry. Two such approaches, using different techniques that exploit each of these properties, have previously been published, and show promising results from both simulation and experimental data for the detection of shielded high-Z materials and density variations from volcanic assay. Both detector systems are based on scintillator and photomultiplier technologies. Results from dedicated simulation studies using both these technologies and image reconstruction techniques are presented for an intermediate-sized nuclear waste storage facility filled with concrete...

  20. Recent Results from RHIC&Some Lessons for Cosmic-RayPhysicists

    SciTech Connect (OSTI)

    Klein, Spencer R.

    2006-10-01

    The Relativistic Heavy Ion Collider (RHIC) studies nuclear matter under a variety of conditions. Cold nuclear matter is probed with deuteron-gold collisions, while hot nuclear matter (possibly a quark-gluon plasma (QGP)) is created in heavy-ion collisions. The distribution of spin in polarized nucleons is measured with polarized proton collisions, and photoproduction is studied using the photons that accompany heavy nuclei. The deuteron-gold data shows less forward particle production than would be expected from a superposition of pp collisions, as expected due to saturation/shadowing. Particle production in AA collisions is well described by a model of an expanding fireball in thermal equilibrium. Strong hydrodynamic flow and jet quenching shows that the produced matter interacts very strongly. These phenomena are consistent with new non-perturbative interactions near the transition temperature to the QGP. This report discusses these results, and their implications for cosmic-ray physicists.

  1. Detection of ultra-high energy cosmic ray showers with a single-pixel fluorescence telescope

    E-Print Network [OSTI]

    Fujii, T; Bertaina, M; Casolino, M; Dawson, B; Horvath, P; Hrabovsky, M; Jiang, J; Mandat, D; Matalon, A; Matthews, J N; Motloch, P; Palatka, M; Pech, M; Privitera, P; Schovanek, P; Takizawa, Y; Thomas, S B; Travnicek, P; Yamazaki, K

    2015-01-01

    We present a concept for large-area, low-cost detection of ultra-high energy cosmic rays (UHECRs) with a Fluorescence detector Array of Single-pixel Tele- scopes (FAST), addressing the requirements for the next generation of UHECR experiments. In the FAST design, a large field of view is covered by a few pixels at the focal plane of a mirror or Fresnel lens. We report first results of a FAST prototype installed at the Telescope Array site, consisting of a single 200 mm photomultiplier tube at the focal plane of a 1 m2 Fresnel lens system taken from the prototype of the JEM-EUSO experiment. The FAST prototype took data for 19 nights, demonstrating remarkable operational stability. We detected laser shots at distances of several kilometres as well as 16 highly significant UHECR shower candidates.

  2. Inferred cosmic-ray spectrum from ${\\it Fermi}$-LAT $\\gamma$-ray observations of the Earth's limb

    E-Print Network [OSTI]

    :,; Ajello, M; Albert, A; Allafort, A; Baldini, L; Barbiellini, G; Bastieri, D; Bechtol, K; Bellazzini, R; Blandford, R D; Bloom, E D; Bonamente, E; Bottacini, E; Bouvier, A; Brandt, T J; Brigida, M; Bruel, P; Buehler, R; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Cecchi, C; Charles, E; Chaves, R C G; Chekhtman, A; Chiang, J; Chiaro, G; Ciprini, S; Claus, R; Cohen-Tanugi, J; Conrad, J; Cutini, S; Dalton, M; D'Ammando, F; de Angelis, A; de Palma, F; Dermer, C D; Digel, S W; Di Venere, L; Silva, E do Couto e; Drell, P S; Drlica-Wagner, A; Favuzzi, C; Fegan, S J; Ferrara, E C; Focke, W B; Franckowiak, A; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Germani, S; Giglietto, N; Giordano, F; Giroletti, M; Glanzman, T; Godfrey, G; Gomez-Vargas, G A; Grenier, I A; Grove, J E; Guiriec, S; Gustafsson, M; Hadasch, D; Hanabata, Y; Harding, A K; Hayashida, M; Hayashi, K; Hewitt, J W; Horan, D; Hou, X; Hughes, R E; Inoue, Y; Jackson, M S; Jogler, T; Jóhannesson, G; Johnson, A S; Kamae, T; Kawano, T; Knödlseder, J; Kuss, M; Lande, J; Larsson, S; Latronico, L; Longo, F; Loparco, F; Lovellette, M N; Lubrano, P; Mayer, M; Mazziotta, M N; McEnery, J E; Mehault, J; Michelson, P F; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nemmen, R; Nuss, E; Ohsugi, T; Okumura, A; Orienti, M; Orlando, E; Ormes, J F; Paneque, D; Panetta, J H; Perkins, J S; Pesce-Rollins, M; Piron, F; Pivato, G; Porter, T A; Rainň, S; Rando, R; Razzano, M; Razzaque, S; Reimer, A; Reimer, O; Ritz, S; Roth, M; Schaal, M; Schulz, A; Sgrň, C; Siskind, E J; Spandre, G; Spinelli, P; Strong, A W; Takahashi, H; Takeuchi, Y; Thayer, J G; Thayer, J B; Thompson, D J; Tibaldo, L; Tinivella, M; Torres, D F; Tosti, G; Troja, E; Tronconi, V; Usher, T L; Vandenbroucke, J; Vasileiou, V; Vianello, G; Vitale, V; Werner, M; Winer, B L; Wood, K S; Wood, M; Yang, Z

    2014-01-01

    Recent accurate measurements of cosmic-ray (CR) species by ATIC-2, CREAM, and PAMELA reveal an unexpected hardening in the proton and He spectra above a few hundred GeV, a gradual softening of the spectra just below a few hundred GeV, and a harder spectrum of He compared to that of protons. These newly-discovered features may offer a clue to the origin of high-energy CRs. We use the ${\\it Fermi}$ Large Area Telescope observations of the $\\gamma$-ray emission from the Earth's limb for an indirect measurement of the local spectrum of CR protons in the energy range $\\sim 90~$GeV-$6~$TeV (derived from a photon energy range $15~$GeV-$1~$TeV). Our analysis shows that single power law and broken power law spectra fit the data equally well and yield a proton spectrum with index $2.68 \\pm 0.04$ and $2.61 \\pm 0.08$ above $\\sim 200~$GeV, respectively.

  3. Corotating solar wind structures and recurrent trains of enhanced diurnal variation in galactic cosmic rays

    SciTech Connect (OSTI)

    Yeeram, T.; Ruffolo, D.; Sáiz, A.; Kamyan, N.; Nutaro, T. E-mail: david.ruf@mahidol.ac.th E-mail: p_chang24@hotmail.com

    2014-04-01

    Data from the Princess Sirindhorn Neutron Monitor at Doi Inthanon, Thailand, with a vertical cutoff rigidity of 16.8 GV, were utilized to determine the diurnal anisotropy (DA) of Galactic cosmic rays (GCRs) near Earth during solar minimum conditions between 2007 November and 2010 November. We identified trains of enhanced DA over several days, which often recur after a solar rotation period (?27 days). By investigating solar coronal holes as identified from synoptic maps and solar wind parameters, we found that the intensity and anisotropy of cosmic rays are associated with the high-speed streams (HSSs) in the solar wind, which are in turn related to the structure and evolution of coronal holes. An enhanced DA was observed after the onset of some, but not all, HSSs. During time periods of recurrent trains, the DA was often enhanced or suppressed according to the sign of the interplanetary magnetic field B, which suggests a contribution from a mechanism involving a southward gradient in the GCR density, n, and a gradient anisotropy along B × ?n. In one non-recurrent and one recurrent sequence, an HSS from an equatorial coronal hole was merged with that from a trailing mid-latitude extension of a polar coronal hole, and the slanted HSS structure in space with suppressed GCR density can account for the southward GCR gradient. We conclude that the gradient anisotropy is a source of temporary changes in the GCR DA under solar minimum conditions, and that the latitudinal GCR gradient can sometimes be explained by the coronal hole morphology.

  4. Cosmic ray neutron background reduction using localized coincidence veto neutron counting

    DOE Patents [OSTI]

    Menlove, Howard O. (Los Alamos, NM); Bourret, Steven C. (Los Alamos, NM); Krick, Merlyn S. (Los Alamos, NM)

    2002-01-01

    This invention relates to both the apparatus and method for increasing the sensitivity of measuring the amount of radioactive material in waste by reducing the interference caused by cosmic ray generated neutrons. The apparatus includes: (a) a plurality of neutron detectors, each of the detectors including means for generating a pulse in response to the detection of a neutron; and (b) means, coupled to each of the neutrons detectors, for counting only some of the pulses from each of the detectors, whether cosmic ray or fission generated. The means for counting includes a means that, after counting one of the pulses, vetos the counting of additional pulses for a prescribed period of time. The prescribed period of time is between 50 and 200 .mu.s. In the preferred embodiment the prescribed period of time is 128 .mu.s. The veto means can be an electronic circuit which includes a leading edge pulse generator which passes a pulse but blocks any subsequent pulse for a period of between 50 and 200 .mu.s. Alternately, the veto means is a software program which includes means for tagging each of the pulses from each of the detectors for both time and position, means for counting one of the pulses from a particular position, and means for rejecting those of the pulses which originate from the particular position and in a time interval on the order of the neutron die-away time in polyethylene or other shield material. The neutron detectors are grouped in pods, preferably at least 10. The apparatus also includes means for vetoing the counting of coincidence pulses from all of the detectors included in each of the pods which are adjacent to the pod which includes the detector which produced the pulse which was counted.

  5. The wavefront of the radio signal emitted by cosmic ray air showers

    E-Print Network [OSTI]

    W. D. Apel; J. C. Arteaga-Velázquez; L. Bähren; K. Bekk; M. Bertaina; P. L. Biermann; J. Blümer; H. Bozdog; I. M. Brancus; E. Cantoni; A. Chiavassa; K. Daumiller; V. de Souza; F. Di Pierro; P. Doll; R. Engel; H. Falcke; B. Fuchs; H. Gemmeke; C. Grupen; A. Haungs; D. Heck; J. R. Hörandel; A. Horneffer; D. Huber; T. Huege; P. G. Isar; K. -H. Kampert; D. Kang; O. Krömer; J. Kuijpers; K. Link; P. Luczak; M. Ludwig; H. J. Mathes; M. Melissas; C. Morello; J. Oehlschläger; N. Palmieri; T. Pierog; J. Rautenberg; H. Rebel; M. Roth; C. Rühle; A. Saftoiu; H. Schieler; A. Schmidt; S. Schoo; F. G. Schröder; O. Sima; G. Toma; G. C. Trinchero; A. Weindl; J. Wochele; J. Zabierowski; J. A. Zensus

    2014-08-07

    Analyzing measurements of the LOPES antenna array together with corresponding CoREAS simulations for more than 300 measured events with energy above $10^{17}\\,$eV and zenith angles smaller than $45^\\circ$, we find that the radio wavefront of cosmic-ray air showers is of approximately hyperbolic shape. The simulations predict a slightly steeper wavefront towards East than towards West, but this asymmetry is negligible against the measurement uncertainties of LOPES. At axis distances $\\gtrsim 50\\,$m, the wavefront can be approximated by a simple cone. According to the simulations, the cone angle is clearly correlated with the shower maximum. Thus, we confirm earlier predictions that arrival time measurements can be used to study the longitudinal shower development, but now using a realistic wavefront. Moreover, we show that the hyperbolic wavefront is compatible with our measurement, and we present several experimental indications that the cone angle is indeed sensitive to the shower development. Consequently, the wavefront can be used to statistically study the primary composition of ultra-high energy cosmic rays. At LOPES, the experimentally achieved precision for the shower maximum is limited by measurement uncertainties to approximately $140\\,$g/cm$^2$. But the simulations indicate that under better conditions this method might yield an accuracy for the atmospheric depth of the shower maximum, $X_\\mathrm{max}$, better than $30\\,$g/cm$^2$. This would be competitive with the established air-fluorescence and air-Cherenkov techniques, where the radio technique offers the advantage of a significantly higher duty-cycle. Finally, the hyperbolic wavefront can be used to reconstruct the shower geometry more accurately, which potentially allows a better reconstruction of all other shower parameters, too.

  6. WIDESPREAD METHANOL EMISSION FROM THE GALACTIC CENTER: THE ROLE OF COSMIC RAYS

    SciTech Connect (OSTI)

    Yusef-Zadeh, F.; Royster, M. [Department of Physics and Astronomy and Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), Northwestern University, Evanston, IL 60208 (United States); Cotton, W. [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States); Viti, S. [Department of Physics and Astronomy, University College London, Gower St. London, WCIE 6BT (United Kingdom); Wardle, M. [Department of Physics and Astronomy, Macquarie University, Sydney NSW 2109 (Australia)

    2013-02-20

    We report the discovery of a widespread population of collisionally excited methanol J = 4{sub -1} to 3{sub 0} E sources at 36.2 GHz from the inner 66' Multiplication-Sign 18' (160 Multiplication-Sign 43 pc) of the Galactic center. This spectral feature was imaged with a spectral resolution of 16.6 km s{sup -1} taken from 41 channels of a Very Large Array continuum survey of the Galactic center region. The revelation of 356 methanol sources, most of which are maser candidates, suggests a large abundance of methanol in the gas phase in the Galactic center region. There is also spatial and kinematic correlation between SiO (2-1) and CH{sub 3}OH emission from four Galactic center clouds: the +50 and +20 km s{sup -1} clouds and G0.13-0.13 and G0.25 + 0.01. The enhanced abundance of methanol is accounted for in terms of induced photodesorption by cosmic rays as they travel through a molecular core, collide, dissociate, ionize, and excite Lyman Werner transitions of H{sub 2}. A time-dependent chemical model in which cosmic rays drive the chemistry of the gas predicts CH{sub 3}OH abundance of 10{sup -8} to 10{sup -7} on a chemical timescale of 5 Multiplication-Sign 10{sup 4} to 5 Multiplication-Sign 10{sup 5} years. The average methanol abundance produced by the release of methanol from grain surfaces is consistent with the available data.

  7. The influence of cosmic rays on the size of the Antarctic Ozone Hole

    E-Print Network [OSTI]

    M. Alvarez Madrigal; J. Perez Peraza; V. M. Velasco

    2010-01-15

    The Antarctic region in which severe ozone depletion has taken place is known as the ozone hole. This region has two basic indicators: the area, where the ozone abundance is low (size), and the quantity of ozone mass deficit (depth). The energetic particles that penetrate deeply into the atmosphere and galactic cosmic rays (GCR) modify the ozone abundance in the stratosphere. With this research project, we are looking for evidence of a connection between variations in the cosmic ray flux and variations in the size of the ozone hole. In addition, we are looking for signs of the kind of processes that physically connect GCR fluxes with variations in the stratospheric ozone hole size (OHS) in the Antarctic region. With this goal in mind, we also analyze here the atmospheric temperature (AT) anomalies, which have often been linked with such variations. Using Morlet's wavelet spectral analysis to compute the coherence between two time series, we found that during the analyzed period (1982-2005), there existed a common signal of around 3 and 5 years between the OHS and GCR time series, during September and November, respectively. In both cases, the relationship showed a time-dependent anti-correlation between the two series. On the other hand, for October the analysis showed a time-dependent correlation that occurs around 1.7 years. These results seem to indicate that there exist at least two kinds of modulation processes of GCR fluxes on the OHS that work simultaneously but that change their relative relevance along the timeline.

  8. The wavefront of the radio signal emitted by cosmic ray air showers

    SciTech Connect (OSTI)

    Apel, W.D.; Bekk, K.; Blümer, J.; Bozdog, H.; Daumiller, K.; Doll, P.; Engel, R.; Arteaga-Velázquez, J.C.; Bähren, L.; Falcke, H.; Bertaina, M.; Cantoni, E.; Chiavassa, A.; Pierro, F. Di; Biermann, P.L.; Brancus, I.M.; De Souza, V.; Fuchs, B.; Gemmeke, H.; Grupen, C.; and others

    2014-09-01

    Analyzing measurements of the LOPES antenna array together with corresponding CoREAS simulations for more than 300 measured events with energy above 10{sup 17} eV and zenith angles smaller than 45{sup o}, we find that the radio wavefront of cosmic-ray air showers is of approximately hyperbolic shape. The simulations predict a slightly steeper wavefront towards East than towards West, but this asymmetry is negligible against the measurement uncertainties of LOPES. At axis distances ?> 50 m, the wavefront can be approximated by a simple cone. According to the simulations, the cone angle is clearly correlated with the shower maximum. Thus, we confirm earlier predictions that arrival time measurements can be used to study the longitudinal shower development, but now using a realistic wavefront. Moreover, we show that the hyperbolic wavefront is compatible with our measurement, and we present several experimental indications that the cone angle is indeed sensitive to the shower development. Consequently, the wavefront can be used to statistically study the primary composition of ultra-high energy cosmic rays. At LOPES, the experimentally achieved precision for the shower maximum is limited by measurement uncertainties to approximately 140 g/c {sup 2}. But the simulations indicate that under better conditions this method might yield an accuracy for the atmospheric depth of the shower maximum, X{sub max}, better than 30 g/c {sup 2}. This would be competitive with the established air-fluorescence and air-Cherenkov techniques, where the radio technique offers the advantage of a significantly higher duty-cycle. Finally, the hyperbolic wavefront can be used to reconstruct the shower geometry more accurately, which potentially allows a better reconstruction of all other shower parameters, too.

  9. Spectrum of Relativistic and Subrelativistic Cosmic Rays in the 100 pc Central Region

    E-Print Network [OSTI]

    Dogiel, V A; Kiselev, A M; Nobukawa, M; Cheng, K S; Hui, C Y; Ko, C M; Nobukawa, K K; Tsuru, T G

    2015-01-01

    From the rate of hydrogen ionization and the gamma ray flux, we derived the spectrum of relativistic and subrelativistic cosmic rays (CRs) nearby and inside the molecular cloud Sgr B2 near the Galactic Center (GC). We studied two cases of CR propagation in molecular clouds: free propagation and scattering of particles by magnetic fluctuations excited by the neutral gas turbulence. We showed that in the latter case CR propagation inside the cloud can be described as diffusion with the coefficient $\\sim 3\\times 10^{27}$ cm$^2$ s$^{-1}$. For the case of hydrogen ionization by subrelativistic protons, we showed that their spectrum outside the cloud is quite hard with the spectral index $\\delta>-1$. The energy density of subrelativistic protons ($>50$ eV cm$^{-3}$) is one order of magnitude higher than that of relativistic CRs. These protons generate the 6.4 keV emission from Sgr B2, which was about 30\\% of the flux observed by Suzaku in 2013. Future observations for the period after 2013 may discover the backgrou...

  10. Chandra Multiwavelength Project X-ray Point Source Number Counts and the Cosmic X-ray Background

    E-Print Network [OSTI]

    Minsun Kim; Belinda J. Wilkes; Dong-Woo Kim; Paul J. Green; Wayne A. Barkhouse; Myung Gyoon Lee; John D. Silverman; Harvey D. Tananbaum

    2006-11-28

    We present the Chandra Multiwavelength Project (ChaMP) X-ray point source number counts and the cosmic X-ray background (CXRB) flux densities in multiple energy bands. From the ChaMP X-ray point source catalog, ~5,500 sources are selected covering 9.6 deg^2 in sky area. To quantitatively characterize the sensitivity and completeness of the ChaMP sample, we perform extensive simulations. We also include the ChaMP+CDFs (Chandra Deep Fields) number counts to cover large flux ranges from 2x10^{-17} to 2.4x10^{-12} (0.5-2 keV) and from 2x10^{-16} to 7.1x10^{-12} (2-8 keV) erg/cm^2/sec. The ChaMP and the ChaMP+CDFs differential number counts are well fitted with a broken power law. The best fit faint and bright power indices are 1.49^{+0.02}_{-0.02} and 2.36^{+0.05}_{-0.05} (0.5-2 keV), and 1.58^{+0.01}_{-0.01} and 2.59^{+0.06}_{-0.05} (2-8 keV), respectively. We detect breaks in the differential number counts and they appear at different fluxes in different energy bands. Assuming a single power law model for a source spectrum, we find that the same population(s) of soft X-ray sources causes the break in the differential number counts for all energy bands. We measure the resolved CXRB flux densities from the ChaMP and the ChaMP+CDFs number counts with and without bright target sources. Adding the known unresolved CXRB to the ChaMP+CDF resolved CXRB, we also estimate total CXRB flux densities. The fractions of the resolved CXRB without target sources are 78^{+1}_{-1}% and 81^{+2}_{-2}% in the 0.5-2 keV and 2-8 keV bands, respectively, somewhat lower, though generally consistent with earlier numbers since their large errors. These fractions increase by ~1% when target sources are included.

  11. At what particle energy do extragalactic cosmic rays start to predominate?

    E-Print Network [OSTI]

    Tadeusz Wibig; Arnold W. Wolfendale

    2004-10-26

    We have argued [J. Szabelski et al. (2002)] that the well-known `ankle' in the cosmic ray energy spectrum, at logE (eV) ~ 18.7-19.0, marks the transition from mainly Galactic sources at lower energies to mainly extragalactic above. Recently, however, there have been claims for lower transitional energies, specifically from logE (eV) ~ 17.0 [G. Thompson et al. (2004)] via 17.2-17.8 [V.S. Berezinsky et al. (2004)] to 18.0 [A.M. Hillas (2004)]. In our model the ankle arises naturally from the sum of simple power law-spectra with slopes differing by ~ 1.8; from differential slope -3.8 for Galactic particles (near logE = 19) to ~ -2.0 for extragalactic sources. In the other models, on the other hand, the ankle is intrinsic to the extragalactic component alone, and arises from the shape of the rate of energy loss versus energy for the (assumed) protons interacting with the cosmic microwave background (CMB). Our detailed analysis of the world's data on the ultra-high energy spectrum shows that taken together, or separately, the resulting mean sharpness of the ankle (second difference of the log(intensity*E^3) with respect to logE) is consistent with our `mixed' model. For explanation in terms of extragalactic particles alone, however, the ankle will be at the wrong energy - for reasonable production models and of insufficient magnitude if, as seems likely, there is still a significant fraction of heavy nuclei at the ankle energy.

  12. Exclusion of cosmic rays in protoplanetary disks. II. Chemical gradients and observational signatures

    SciTech Connect (OSTI)

    Cleeves, L. Ilsedore; Bergin, Edwin A.; Adams, Fred C. [Department of Astronomy, University of Michigan, 1085 South University Avenue, Ann Arbor, MI 48109 (United States)

    2014-10-20

    The chemical properties of protoplanetary disks are especially sensitive to their ionization environment. Sources of molecular gas ionization include cosmic rays (CRs), stellar X-rays, and short-lived radionuclides, each of which varies with location in the disk. This behavior leads to a significant amount of chemical structure, especially in molecular ion abundances, which is imprinted in their submillimeter rotational line emission. Using an observationally motivated disk model, we make predictions for the dependence of chemical abundances on the assumed properties of the ionizing field. We calculate the emergent line intensity for abundant molecular ions and simulate sensitive observations with the Atacama Large Millimeter/Sub-millimeter Array (ALMA) for a disk at D = 100 pc. The models readily distinguish between high ionization rates (? ? 10{sup –17} s{sup –1} per H{sub 2}) and below, but it becomes difficult to distinguish between low ionization models when ? ? 10{sup –19} s{sup –1}. We find that H{sub 2}D{sup +} emission is not detectable for sub-interstellar CR rates with ALMA (6h integration), and that N{sub 2}D{sup +} emission may be a more sensitive tracer of midplane ionization. HCO{sup +} traces X-rays and high CR rates (?{sub CR} ? 10{sup –17} s{sup –1}), and provides a handle on the warm molecular ionization properties where CO is present in the gas. Furthermore, species like HCO{sup +}, which emits from a wide radial region and samples a large gradient in temperature, can exhibit ring-like emission as a consequence of low-lying rotational level de-excitation near the star. This finding highlights a scenario where rings are not necessarily structural or chemical in nature, but simply a result of the underlying line excitation properties.

  13. Accelerator measurements of magnetically-induced radio emission from particle cascades with applications to cosmic-ray air showers

    E-Print Network [OSTI]

    K. Belov; K. Mulrey; A. Romero-Wolf; S. A. Wissel; A. Zilles; K. Bechtol; K. Borch; P. Chen; J. Clem; P. W. Gorham; C. Hast; T. Huege; R. Hyneman; K. Jobe; K. Kuwatani; J. Lam; T. Liu; J. Nam; C. Naudet; R. Nichol; B. F. Rauch; B. Rotter; D. Saltzberg; H. Schoorlemmer; D. Seckel; B. Strutt; A. G. Vieregg; C. Williams

    2015-07-27

    An experiment at SLAC provides the first beam test of radio-frequency (RF) radiation from a charged particle cascade in the presence of a magnetic field (up to $\\sim$1~kG), a model system for RF emission from a cosmic-ray air shower. This experiment provides a suite of controlled laboratory measurements to compare to particle-level simulations of RF emission, which are relied upon in ultra-high-energy cosmic-ray air shower detection. We compare simulations to data for intensity, linearity with magnetic field, angular distribution, polarization, and spectral content. In particular, we confirm recent predictions that the magnetically induced emission forms a beam that peaks at the Cherenkov angle and show that the simulations reproduce the data within systematic uncertainties.

  14. Electron and Positron Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station

    E-Print Network [OSTI]

    Aguilar, M; Alvino, A; Ambrosi, G; Andeen, K; Arruda, L; Attig, N; Azzarello, P; Bachlechner, A; Barao, F; Barrau, A; Barrin, L; Bartoloni, A; Basara, L; Battarbee, M; Battiston, R; Bazo, J; Becker, U; Behlmann, M; Beischer, B; Berdugo, J; Bertucci, B; Bigongiari, G; Bindi, V; Bizzaglia, S; Bizzarri, M; Boella, G; de Boer, W; Bollweg, K; Bonnivard, V; Borgia, B; Borsini, S; Boschini, M J; Bourquin, M; Burger, J; Cadoux, F; Cai, X D; Capell, M; Caroff, S; Casaus, J; Cascioli, V; Castellini, G; Cernuda, I; Cervelli, F; Chae, M J; Chang, Y H; Chen, A I; Chen, H; Cheng, G M; Chen, H S; Cheng, L; Chikanian, A; Chou, H Y; Choumilov, E; Choutko, V; Chung, C H; Clark, C; Clavero, R; Coignet, G; Consolandi, C; Contin, A; Corti, C; Coste, B; Cui, Z; Dai, M; Delgado, C; Della Torre, S; Demirköz, M B; Derome, L; Di Falco, S; Di Masso, L; Dimiccoli, F; Díaz, C; von Doetinchem, P; Du, W J; Duranti, M; D’Urso, D; Eline, A; Eppling, F J; Eronen, T; Fan, Y Y; Farnesini, L; Feng, J; Fiandrini, E; Fiasson, A; Finch, E; Fisher, P; Galaktionov, Y; Gallucci, G; García, B; García-López, R; Gast, H; Gebauer, I; Gervasi, M; Ghelfi, A; Gillard, W; Giovacchini, F; Goglov, P; Gong, J; Goy, C; Grabski, V; Grandi, D; Graziani, M; Guandalini, C; Guerri, I; Guo, K H; Habiby, M; Haino, S; Han, K C; He, Z H; Heil, M; Hoffman, J; Hsieh, T H; Huang, Z C; Huh, C; Incagli, M; Ionica, M; Jang, W Y; Jinchi, H; Kanishev, K; Kim, G N; Kim, K S; Kirn, Th; Kossakowski, R; Kounina, O; Kounine, A; Koutsenko, V; Krafczyk, M S; Kunz, S; La Vacca, G; Laudi, E; Laurenti, G; Lazzizzera, I; Lebedev, A; Lee, H T; Lee, S C; Leluc, C; Li, H L; Li, J Q; Li, Q; Li, Q; Li, T X; Li, W; Li, Y; Li, Z H; Li, Z Y; Lim, S; Lin, C H; Lipari, P; Lippert, T; Liu, D; Liu, H; Lomtadze, T; Lu, M J; Lu, Y S; Luebelsmeyer, K; Luo, F; Luo, J Z; Lv, S S; Majka, R; Malinin, A; Mańá, C; Marín, J; Martin, T; Martínez, G; Masi, N; Maurin, D; Menchaca-Rocha, A; Meng, Q; Mo, D C; Morescalchi, L; Mott, P; Müller, M; Ni, J Q; Nikonov, N; Nozzoli, F; Nunes, P; Obermeier, A; Oliva, A; Orcinha, M; Palmonari, F; Palomares, C; Paniccia, M; Papi, A; Pedreschi, E; Pensotti, S; Pereira, R; Pilo, F; Piluso, A; Pizzolotto, C; Plyaskin, V; Pohl, M; Poireau, V; Postaci, E; Putze, A; Quadrani, L; Qi, X M; Rancoita, P G; Rapin, D; Ricol, J S; Rodríguez, I; Rosier-Lees, S; Rozhkov, A; Rozza, D; Sagdeev, R; Sandweiss, J; Saouter, P; Sbarra, C; Schael, S; Schmidt, S M; Schuckardt, D; Schulz von Dratzig, A; Schwering, G; Scolieri, G; Seo, E S; Shan, B S; Shan, Y H; Shi, J Y; Shi, X Y; Shi, Y M; Siedenburg, T; Son, D; Spada, F; Spinella, F; Sun, W; Sun, W H; Tacconi, M; Tang, C P; Tang, X W; Tang, Z C; Tao, L; Tescaro, D; Ting, Samuel C C; Ting, S M; Tomassetti, N; Torsti, J; Türko?lu, C; Urban, T; Vagelli, V; Valente, E; Vannini, C; Valtonen, E; Vaurynovich, S; Vecchi, M; Velasco, M; Vialle, J P; Wang, L Q; Wang, Q L; Wang, R S; Wang, X; Wang, Z X; Weng, Z L; Whitman, K; Wienkenhöver, J; Wu, H; Xia, X; Xie, M; Xie, S; Xiong, R Q; Xin, G M; Xu, N S; Xu, W; Yan, Q; Yang, J; Yang, M; Ye, Q H; Yi, H; Yu, Y J; Yu, Z Q; Zeissler, S; Zhang, J H; Zhang, M T; Zhang, X B; Zhang, Z; Zheng, Z M; Zhuang, H L; Zhukov, V; Zichichi, A; Zimmermann, N; Zuccon, P; Zurbach, C

    2014-01-01

    Precision measurements by the Alpha Magnetic Spectrometer on the International Space Station of the primary cosmic-ray electron flux in the range 0.5 to 700 GeV and the positron flux in the range 0.5 to 500 GeV are presented. The electron flux and the positron flux each require a description beyond a single power-law spectrum. Both the electron flux and the positron flux change their behavior at ?30??GeV but the fluxes are significantly different in their magnitude and energy dependence. Between 20 and 200 GeV the positron spectral index is significantly harder than the electron spectral index. The determination of the differing behavior of the spectral indices versus energy is a new observation and provides important information on the origins of cosmic-ray electrons and positrons.

  15. On evolution of Primary Cosmic Ray mass composition in the energy region $10^{14}-10^{16}$ eV

    E-Print Network [OSTI]

    Yu. F. Novoseltsev; G. M. Vereshkov

    2013-11-16

    A new method of determining Primary Cosmic Ray mass composition is proposed. The method is based on quasi-localization of the integral equation for the Extensive Air Showers spectrum versus the total number of high energy muons ($E_\\mu \\geqslant 235$ GeV) and an expansion of the experimentally measured spectrum in spectra of five group of primary nuclei. The cosmic ray mass composition is established in the energy region $10^{14}-10^{16}$ eV. In the region $10^{15}-10^{16}$ eV our analysis points to a lightening of the mass composition from $p+\\alpha \\simeq 0.54,\\ \\langle \\ln A \\rangle \\simeq 1.97$ to $p+\\alpha \\simeq 0.69,\\ \\langle \\ln A \\rangle\\simeq 1.56$.

  16. Observation in the MINOS far detector of the shadowing of cosmic rays by the sun and moon

    SciTech Connect (OSTI)

    Adamson, P.; Andreopoulos, C.; Ayres, D.S.; Backhouse, C.; Barr, G.; Barrett, W.L.; Bishai, M.; Blake, A.; Bock, B.; Bock, G.J.; Boehnlein, D.J.

    2010-08-01

    The shadowing of cosmic ray primaries by the the moon and sun was observed by the MINOS far detector at a depth of 2070 mwe using 83.54 million cosmic ray muons accumulated over 1857.91 live-days. The shadow of the moon was detected at the 5.6 {sigma} level and the shadow of the sun at the 3.8 {sigma} level using a log-likelihood search in celestial coordinates. The moon shadow was used to quantify the absolute astrophysical pointing of the detector to be 0.17 {+-} 0.12{sup o}. Hints of Interplanetary Magnetic Field effects were observed in both the sun and moon shadow.

  17. The knee in the cosmic ray energy spectrum from the simultaneous EAS charged particles and muon density spectra

    E-Print Network [OSTI]

    Bijay, Biplab; Bhadra, Arunava

    2015-01-01

    In this work we examine with the help of Monte Carlo simulation whether a consistent primary energy spectrum of cosmic rays emerges from both the experimentally observed total charged particles and muon size spectra of cosmic ray extensive air showers considering primary composition may or may not change beyond the knee of the energy spectrum. It is found that EAS-TOP observations consistently infer a knee in the primary energy spectrum provided the primary is pure unchanging iron whereas no consistent primary spectrum emerges from simultaneous use of the KASCADE observed total charged particle and muon spectra. However, it is also found that when primary composition changes across the knee the estimation of spectral index of total charged particle spectrum is quite tricky, depends on the choice of selection of points near the knee in the size spectrum.

  18. A search for anisotropy in the arrival directions of ultra high energy cosmic rays recorded at the Pierre Auger Observatory

    SciTech Connect (OSTI)

    Abreu, P.; ,

    2012-01-01

    Observations of cosmic ray arrival directions made with the Pierre Auger Observatory have previously provided evidence of anisotropy at the 99% CL using the correlation of ultra high energy cosmic rays (UHECRs) with objects drawn from the Veron-Cetty Veron catalog. In this paper we report on the use of three catalog independent methods to search for anisotropy. The 2pt-L, 2pt+ and 3pt methods, each giving a different measure of self-clustering in arrival directions, were tested on mock cosmic ray data sets to study the impacts of sample size and magnetic smearing on their results, accounting for both angular and energy resolutions. If the sources of UHECRs follow the same large scale structure as ordinary galaxies in the local Universe and if UHECRs are deflected no more than a few degrees, a study of mock maps suggests that these three methods can efficiently respond to the resulting anisotropy with a P-value = 1.0% or smaller with data sets as few as 100 events. Using data taken from January 1, 2004 to July 31, 2010 we examined the 20, 30, ..., 110 highest energy events with a corresponding minimum energy threshold of about 51 EeV. The minimum P-values found were 13.5% using the 2pt-L method, 1.0% using the 2pt+ method and 1.1% using the 3pt method for the highest 100 energy events. In view of the multiple (correlated) scans performed on the data set, these catalog-independent methods do not yield strong evidence of anisotropy in the highest energy cosmic rays.

  19. Study of Cosmic-Ray Modulation during the Recent Unusual Minimum and Mini Maximum of Solar Cycle 24

    E-Print Network [OSTI]

    Aslam, O P M

    2015-01-01

    After a prolonged and deep solar minimum at the end of Cycle 23, the current Solar Cycle 24 is one of the lowest cycles. These two periods of deep minimum and mini maximum are separated by a period of increasing solar activity. We study the cosmic-ray intensity variation in relation with the solar activity, heliospheric plasma and field parameters, including the heliospheric current sheet, during these three periods (phases) of different activity level and nature: (a) a deep minimum, (b) an increasing activity period and (c) a mini maximum. We use neutron monitor data from stations located around the globe to study the rigidity dependence on modulation during the two extremes, i.e., minimum and maximum. We also study the time lag between the cosmic-ray intensity and various solar and interplanetary parameters separately during the three activity phases. We also analyze the role of various parameters, including the current sheet tilt, in modulating the cosmic-ray intensity during the three different phases. Th...

  20. Launching Cosmic ray-driven Outflows from the magnetized interstellar medium

    E-Print Network [OSTI]

    Girichidis, Philipp; Walch, Stefanie; Hanasz, Michal; Mac Low, Mordecai-Mark; Ostriker, Jeremiah P; Gatto, Andrea; Peters, Thomas; Wünsch, Richard; Glover, Simon C O; Klessen, Ralf S; Clark, Paul C; Baczynski, Christian

    2015-01-01

    We present a hydrodynamical simulation of the turbulent, magnetized, supernova-driven interstellar medium (ISM) in a stratified box that dynamically couples the injection and evolution of cosmic rays (CRs) and a self-consistent evolution of the chemical composition. CRs are treated as a relativistic fluid in the advection-diffusion approximation. The thermodynamic evolution of the gas is computed using a chemical network that follows the abundances of H+, H, H2, CO, C+, and free electrons and includes (self-)shielding of the gas and dust. We find that CRs perceptibly thicken the disk with the heights of 90% (70%) enclosed mass reaching ~1.5 kpc (~0.2 kpc). The simulations indicate that CRs alone can launch and sustain strong outflows of atomic and ionized gas with mass loading factors of order unity, even in solar neighbourhood conditions and with a CR energy injection per supernova (SN) of 10^50 erg, 10% of the fiducial thermal energy of a SN. The CR-driven outflows have moderate launching velocities close t...

  1. Dominant Contributions to Lateral Distribution Functions in Ultra-High Energy Cosmic Ray Air Showers

    E-Print Network [OSTI]

    Hans-Joachim Drescher; Glennys R. Farrar

    2002-06-12

    In hadron induced air showers of highest energies (E> 1e18 eV), the lateral distribution functions of electrons and muons are a superposition of many separate electromagnetic sub-showers, initiated by meson decay at different altitudes and energies. The lateral distribution function is the primary tool for reconstructing the energy of the primary in a UHE cosmic ray shower, so understanding it in detail is a prerequisite for having confidence in the energy determination. We analyze in this paper the dominant contributions to the ground level lateral distribution functions, as a function of the altitude and energy at which the sub-showers are initiated. Far from the core, the dominant contribution to the density of electrons comes from sub-showers initiated at low altitudes and low energies (E<100 GeV). The dominant sub-showers are initiated at large radial distance from the core and at a large angle with respect to the main shower axis. This demonstrates the need for careful treatment of low energy hadron physics modeling even for ultrahigh energy primaries.

  2. CORRELATIONS BETWEEN ULTRAHIGH ENERGY COSMIC RAYS AND INFRARED-LUMINOUS GALAXIES

    SciTech Connect (OSTI)

    Berlind, Andreas A. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Farrar, Glennys R.; Zaw, Ingyin [Center for Cosmology and Particle Physics and Department of Physics, New York University, New York, NY 10003 (United States)

    2010-06-20

    We confirm the ultrahigh energy cosmic ray (UHECR) horizon established by the Pierre Auger Observatory using the heterogeneous Veron-Cetty-Veron (VCV) catalog of active galactic nuclei by performing a redshift-angle-IR luminosity scan using point-source catalog with redshift (PSCz) galaxies having infrared luminosity greater than 10{sup 10} L{sub sun}. The strongest correlation-for z < 0.016, {psi} = 2.{sup 0}1, and L{sub ir} {>=} 10{sup 10.5} L{sub sun}-arises in fewer than 0.3% of scans with isotropic source directions. When we apply a penalty for using the UHECR energy threshold that was tuned to maximize the correlation with VCV, the significance degrades to 1.1%. Since the PSCz catalog is complete and volume-limited for these parameters, this suggests that the UHECR horizon discovered by the Pierre Auger Observatory is not an artifact of the incompleteness and other idiosyncrasies of the VCV catalog. The strength of the correlation between UHECRs and the nearby highest-IR-luminosity PSCz galaxies is stronger than in about 90% of trials with scrambled luminosity assignments for the PSCz galaxies. If confirmed by future data, this result would indicate that the sources of UHECRs are more strongly associated with luminous IR galaxies than with ordinary, lower IR luminosity galaxies.

  3. Non-linear cosmic ray Galactic transport in the light of AMS-02 and Voyager data

    E-Print Network [OSTI]

    Aloisio, Roberto; Serpico, Pasquale

    2015-01-01

    Context: Features in the spectra of primary cosmic rays (CRs) provide invaluable information on the propagation of these particles in the Galaxy. In the rigidity region around a few hundred GV, such features have been measured in the proton and helium spectra by the PAMELA experiment and later confirmed with a higher significance by AMS-02. We investigate the implications of these datasets for the scenario in which CRs propagate under the action of self-generated waves. Aims: We show that the recent data on the spectrum of protons and helium nuclei as collected with AMS-02 and Voyager are in very good agreement with the predictions of a model in which the transport of Galactic CRs is regulated by self-generated waves. We also study the implications of the scenario for the boron-to-carbon ratio: although a good overall agreement is found, at high energy we find marginal support for a (quasi) energy independent contribution to the grammage, that we argue may come from the sources themselves Results: A break in ...

  4. Large-scale anisotropy of TeV-band cosmic rays

    SciTech Connect (OSTI)

    Kumar, Rahul; Eichler, David [Phyiscs Department, Ben-Gurion University, Be'er-Sheba 84105 (Israel)

    2014-04-20

    The expected anisotropy in the 1 to 10{sup 4} TeV energy range is calculated for Galactic cosmic rays with both anisotropy in the diffusion tensor and source discreteness taken into account. We find that if the sources are distributed radially (but with azimuthal symmetry) in proportion to Galactic pulsars, the expected anisotropy almost always exceeds the observational limits by one order of magnitude in the case of isotropic diffusion. If the radial diffusion is more than an order of magnitude smaller than the azimuthal diffusion rate, the radial gradient of the sources can be accommodated about 5% of the time. If the sources are concentrated in the spiral arms, then the anisotropy depends on our location between them, but in some spatial window, roughly equidistant from adjacent spiral arms, the observational constraints on anisotropy are obeyed roughly 20%-30% of the time for extremely anisotropic diffusion. The solar system is in that window less than 10% of the time, but it may be there now. Under the assumption of isotropic diffusion, nearby supernovae are found to produce a discreteness anisotropy that is nearly two orders of magnitude in excess of the observational limit if all supernovae are assumed to contribute equally with a source rate 1 in every 100 years.

  5. Cosmic ray velocity and electric charge measurements with the AMS/RICH detector: prototype results

    E-Print Network [OSTI]

    Luísa Arruda; Fernando Barăo; Patrícia Gonçalves; Rui Pereira

    2008-01-31

    The Alpha Magnetic Spectrometer (AMS) to be installed on the International Space Station (ISS) will measure charged cosmic ray spectra of elements up to iron, in the rigidity range from 1 GV to 1 TV, for at least three years. AMS is a large angular spectrometer composed of different subdetectors, including a proximity focusing Ring Imaging CHerenkov (RICH) detector. This will be equipped with a mixed radiator made of aerogel and sodium fluoride (NaF), a lateral conical mirror and a detection plane made of 680 photomultipliers coupled to light guides. The RICH detector allows measurements of particle's electric charge up to iron, and particle's velocity. Two possible methods for reconstructing the Cherenkov angle and the electric charge with the RICH will be discussed. A RICH prototype consisting of a detection matrix with 96 photomultipliers, a segment of a conical mirror and samples of the radiator materials was built and its performance was evaluated using ion beam data. Results from the last test beam performed with ion fragments resulting from the collision of a 158 GeV/c/nucleon primary beam of indium ions (CERN SPS) on a lead target are reported. The large amount of collected data allowed to test and characterize different aerogel samples and the NaF radiator. In addition, the reflectivity of the mirror was evaluated. The data analysis confirms the design goals.

  6. RELATIVE COMPOSITION AND ENERGY SPECTRA OF LIGHT NUCLEI IN COSMIC RAYS: RESULTS FROM AMS-01

    SciTech Connect (OSTI)

    Aguilar, M.; Alcaraz, J.; Berdugo, J. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, CIEMAT, E-28040 Madrid (Spain); Allaby, J. [European Laboratory for Particle Physics, CERN, CH-1211 Geneva 23 (Switzerland); Alpat, B.; Ambrosi, G.; Azzarello, P.; Battiston, R. [INFN-Sezione di Perugia, I-06100 Perugia (Italy); Anderhub, H. [Eidgenoessische Technische Hochschule, ETH Zuerich, CH-8093 Zuerich (Switzerland); Ao, L. [Chinese Academy of Launching Vehicle Technology, CALT, 100076 Beijing (China); Arefiev, A. [Institute of Theoretical and Experimental Physics, ITEP, Moscow 117259 (Russian Federation); Arruda, L.; Barao, F.; Barreira, G. [Laboratorio de Instrumentacao e Fisica Experimental de Particulas, LIP, P-1000 Lisboa (Portugal); Basile, M.; Bellagamba, L. [University of Bologna and INFN-Sezione di Bologna, I-40126 Bologna (Italy); Bartoloni, A. [INFN-Sezione di Roma, I-00185 Roma (Italy); Becker, R.; Becker, U. [Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Bene, P., E-mail: nicola.tomassetti@pg.infn.i [DPNC, Universite de Geneve, CH-1211 GENEVA 4 (Switzerland)

    2010-11-20

    Measurement of the chemical and isotopic composition of cosmic rays is essential for the precise understanding of their propagation in the galaxy. While the model parameters are mainly determined using the B/C ratio, the study of extended sets of ratios can provide stronger constraints on the propagation models. In this paper, the relative abundances of light-nuclei lithium, beryllium, boron, and carbon are presented. The secondary-to-primary ratios Li/C, Be/C, and B/C have been measured in the kinetic energy range 0.35-45 GeV nucleon{sup -1}. The isotopic ratio {sup 7}Li/{sup 6}Li is also determined in the magnetic rigidity interval 2.5-6.3 GV. The secondary-to-secondary ratios Li/Be, Li/B, and Be/B are also reported. These measurements are based on the data collected by the Alpha Magnetic Spectrometer AMS-01 during the STS-91 space shuttle flight in 1998 June. Our experimental results are in substantial agreement with other measurements, where they exist. We describe our light-nuclei data with a diffusive-reacceleration model. A 10%-15% overproduction of Be is found in the model predictions and can be attributed to uncertainties in the production cross-section data.

  7. Relative Composition and Energy Spectra of Light Nuclei in Cosmic Rays. Results from AMS-01

    E-Print Network [OSTI]

    The AMS-01 Collaboration

    2011-01-08

    Measurement of the chemical and isotopic composition of cosmic rays is essential for the precise understanding of their propagation in the galaxy. While the model parameters are mainly determined using the B/C ratio, the study of extended sets of ratios can provide stronger constraints on the propagation models. In this paper the relative abundances of the light nuclei lithium, beryllium, boron and carbon are presented. The secondary to primary ratios Li/C, Be/C and B/C have been measured in the kinetic energy range 0.35-45 GeV/nucleon. The isotopic ratio 7Li/6Li is also determined in the magnetic rigidity interval 2.5-6.3 GV. The secondary to secondary ratios Li/Be, Li/B and Be/B are also reported. These measurements are based on the data collected by the Alpha Magnetic Spectrometer AMS-01 during the STS-91 space shuttle flight in 1998 June. Our experimental results are in substantial agreement with other measurements, where they exist. We describe our light-nuclei data with a diffusive-reacceleration model. A 10-15% overproduction of Be is found in the model predictions and can be attributed to uncertainties in the production cross-section data.

  8. Relative Composition and Energy Spectra of Light Nuclei in Cosmic Rays. Results from AMS-01

    E-Print Network [OSTI]

    Aguilar, M; Allaby, J; Alpat, B; Ambrosi, G; Anderhub, H; Ao, L; Arefiev, A; Arruda, L; Azzarello, P; Basile, M; Barao, F; Barreira, G; Vartoloni, A; Battiston, R; Becker, R; Becker, U; Bellagamba, L; Bene, P; Berdugo, J; Berges, P; Bertucci, B; Biland, A; Bindi, V; Boella, G; Boschini, M; Bourquin, M; Bruni, G; Buenerd, M; Burger, J D; Burger, W J; Cai, X D; Cannarsa, P; Capell, M; Casadei, D; Casaus, J; Castellini, G; Cernuda, I; Chang, Y H; Chen, H F; Chen, H S; Chen, Z G; Chernoplekov, N A; Chiueh, T H; Choi, Y Y; Cindolo, F; Commichau, V; Contin, A; Cortina-Gil, E; Crespo, D; Cristinziani, M; Dai, T S; Dela Guia, C; Delgado, C; Di Falco, S; Djambazov, L; D'Antoine, I; Dong, Z R; Duranti, M; Engelberg, J; Eppling, F J; Eronen, T; Extermann, P; Favier, J; Fiandrini, E; Fisher, P H; Flugge, G; Fouque, N; Galaktionov, Y; Gervasi, M; Giovacchini, F; Giusti, P; Grandi, D; Grimm, O; Gu, W Q; Haino, S; Hangarter, K; Hasan, A; Hermel, V; Hofer, H; Hungerford, W; Ionica, M; Jongmanns, M; Karlamaa, K; Karpinski, W; Kenney, G; Kim, D H; Kim, G N; Kim, K S; Kirn, T; Klimentov, A; Kossakowski, R; Kounine, A; Koutsenko, V; Kraeber, M; Laborie, G; Laitinen, T; Lamanna, G; Laurenti, G; Lebedev, A; Lechanoine-Leluc, C; Lee, M W; Lee, S C; Levi, G; Lin, C H; Liu, H T; Lu, G; Lubelsmeyer, K; Luckey, D; Lustermann, W; Mana, C; Margotti, A; Mayet, F; McNeil, R R; Menichelli, M; Mihul, A; Mujunen, A; Oliva, A; Palmonari, F; Park, H B; Park, W H; Pauluzzi, M; Pauss, F; Pereira, R; Perrin, E; Pevsner, A; Pilo, F; Pimenta, M; Plyaskin, V; Pojidaev, V; Pohl, M; Produit, N; Quadrani, L; Rancoita, P G; Rapin, D; Ren, D; Ren, Z; Ribordy, M; Richeux, J P; Riihonen, E; Ritakari, J; Ro, S; Roeser, U; Sagdeev, R; Santos, D; Sartorelli, G; Sbarra, C; Schael, S; Schultz von Dratzig, A; Schwering, G; Seo, E S; Shin, J W; Shoumilov, E; Shoutko, V; Siedenburg, T; Siedling, R; Son, D; Song, T; Spada, F R; Spinella, F; Steuer, M; Sun, G S; Suter, H; Tang, X W; Ting, Samuel C C; Ting, S M; Tomassetti, N; Tornikoski, M; Torsti, J; Trumper, J; Ulbricht, J; Urpo, S; Valtonen, E; Vandenhirtz, J; Velikhov, E; Verlaat, B; Vetlitsky, I; Vezzu, F; Vialle, J P; Viertel, G; Vite, D; Von Gunten, H; Waldmeier Wicki, S; Wallraff, W; Wang, J Z; Wiik, K; Williams, C; Wu, S X; Xia, P C; Xu, S; Xu, Z Z; Yan, J L; Yan, L G; Yang, C G; Yang, J; Yang, M; Ye, S W; Zhang, H Y; Zhang, Z P; Zhao, D X; Zhou, F; Zhou, Y; Zhu, G Y; Zhu, W Z; Zhuang, H L; Zichichi, A; Zimmermann, B; Zuccon, P

    2010-01-01

    Measurement of the chemical and isotopic composition of cosmic rays is essential for the precise understanding of their propagation in the galaxy. While the model parameters are mainly determined using the B/C ratio, the study of extended sets of ratios can provide stronger constraints on the propagation models. In this paper the relative abundances of the light nuclei lithium, beryllium, boron and carbon are presented. The secondary to primary ratios Li/C, Be/C and B/C have been measured in the kinetic energy range 0.35-45 GeV/nucleon. The isotopic ratio 7Li/6Li is also determined in the magnetic rigidity interval 2.5-6.3 GV. The secondary to secondary ratios Li/Be, Li/B and Be/B are also reported. These measurements are based on the data collected by the Alpha Magnetic Spectrometer AMS-01 during the STS-91 space shuttle flight in 1998 June. Our experimental results are in substantial agreement with other measurements, where they exist. We describe our light-nuclei data with a diffusive-reacceleration model....

  9. Cosmic ray velocity and electric charge measurements with the AMS/RICH detector: prototype results

    E-Print Network [OSTI]

    Arruda, Luísa; Gonçalves, Patrícia; Pereira, Rui

    2008-01-01

    The Alpha Magnetic Spectrometer (AMS) to be installed on the International Space Station (ISS) will measure charged cosmic ray spectra of elements up to iron, in the rigidity range from 1 GV to 1 TV, for at least three years. AMS is a large angular spectrometer composed of different subdetectors, including a proximity focusing Ring Imaging CHerenkov (RICH) detector. This will be equipped with a mixed radiator made of aerogel and sodium fluoride (NaF), a lateral conical mirror and a detection plane made of 680 photomultipliers coupled to light guides. The RICH detector allows measurements of particle's electric charge up to iron, and particle's velocity. Two possible methods for reconstructing the Cherenkov angle and the electric charge with the RICH will be discussed. A RICH prototype consisting of a detection matrix with 96 photomultipliers, a segment of a conical mirror and samples of the radiator materials was built and its performance was evaluated using ion beam data. Results from the last test beam perf...

  10. The isotropy problem of sub-ankle ultra high energy cosmic rays

    SciTech Connect (OSTI)

    Kumar, Rahul; Eichler, David [Physics Department, Ben-Gurion University, Be'er-Sheba 84105 (Israel)

    2014-01-20

    We study the time dependent propagation of sub-ankle ultra high energy cosmic rays (UHECRs) originating from point-like Galactic sources. We show that drift in the Galactic magnetic field (GMF) may play an important role in the propagation of UHECRs and their measured anisotropy, particularly when the transport is anisotropic. To fully account for the discreteness of UHECR sources in space and time, a Monte Carlo method is used to randomly place sources in the Galaxy. The low anisotropy measured by Auger is not generally characteristic of the theoretical models, given that the sources are distributed in proportion to the star formation rate, but it can possibly be understood as (1) intermittency effects due to the discrete nature of the sources or, with extreme parameters, (2) a cancellation of drift current along a current sheet with outward radial diffusive flux. We conclude that it is possible to interpret the Galactic sub-ankle CR flux as being due entirely to intermittent discrete Galactic sources distributed in proportion to star formation, but only with a probability of roughly 35%, of which the spectrum is in accord with observations about 30% of the time. An alternative explanation for the low anisotropy may be that they are mostly extragalactic and/or heavy.

  11. Measurements of the Cosmic-Ray Positron Fraction From 1 to 50 GeV

    E-Print Network [OSTI]

    HEAT Collaboration; S. W. Barwick; E. Schneider; J. J. Beatty; G. A. de Nolfo; A. Bhattacharyya; C. R. Bower; J. A. Musser; C. J. Chaput; S. Coutu; S. McKee; G. Tarle; A. D. Tomasch; J. Knapp; D. M. Lowder; D. Muller; S. P. Swordy; E. Torbet; S. L. Nutter

    1997-03-28

    Two measurements of the cosmic-ray positron fraction as a function of energy have been made using the High Energy Antimatter Telescope (HEAT) balloon-borne instrument. The first flight took place from Ft. Sumner, New Mexico in 1994, and yielded results above the geomagnetic cutoff energy of 4.5 GeV. The second flight from Lynn Lake, Manitoba in 1995 permitted measurements over a larger energy interval, from 1 GeV to 50 GeV. In this letter we present results on the positron fraction based on data from the Lynn Lake flight, and compare these with the previously published results from the Ft. Sumner flight. The results confirm that the positron fraction does not increase with energy above ~10 GeV, although a small excess above purely secondary production cannot be ruled out. At low energies the positron fraction is slightly larger than that reported from measurements made in the 1960's. This effect could possibly be a consequence of charge dependence in the level of solar modulation.

  12. Energy Spectra of Elemental Groups of Cosmic Rays: Update on the KASCADE Unfolding Analysis

    E-Print Network [OSTI]

    KASCADE Collaboration; W. D. Apel

    2008-12-01

    The KASCADE experiment measures extensive air showers induced by cosmic rays in the energy range around the so-called knee. The data of KASCADE have been used in a composition analysis showing the knee at 3-5 PeV to be caused by a steepening in the light-element spectra. Since the applied unfolding analysis depends crucially on simulations of air showers, different high energy hadronic interaction models (QGSJet and SIBYLL) were used. The results have shown a strong dependence of the relative abundance of the individual mass groups on the underlying model. In this update of the analysis we apply the unfolding method with a different low energy interaction model (FLUKA instead of GHEISHA) in the simulations. While the resulting individual mass group spectra do not change significantly, the overall description of the measured data improves by using the FLUKA model. In addition data in a larger range of zenith angle are analysed. The new results are completely consistent, i.e. there is no hint to any severe problem in applying the unfolding analysis method to KASCADE data.

  13. An Optimization of the FPGA Based Wavelet Trigger in Radio Detection of Cosmic Rays

    E-Print Network [OSTI]

    ,

    2014-01-01

    Experiments that observe coherent radio emission from extensive air showers induced by ultra-high energy cosmic rays are designed for a detailed study of the development of the electromagnetic part of air showers. Radio detectors can operate with 100% up time as e.g. surface detectors based on water-Cherenkov tanks. They are being developed for ground-based experiments (e.g. the Pierre Auger Observatory) as another type of air shower detector in addition to the fluorescence detectors, which operate with only ~10% of duty in dark nights. The radio signals from air showers are caused by the coherent emission due to geomagnetic radiation and charge excess processes. Currently used self-triggers in radio detectors often generate a dense stream of data, which is analyzed afterwards. Huge amounts of registered data requires a significant man-power for the off-line analysis. An improvement of the trigger efficiency becomes a relevant factor. In this work, Morlet wavelets with various scaling factors were used for an...

  14. Towards unravelling the structural distribution of ultra-high-energy cosmic ray sources

    E-Print Network [OSTI]

    Hajime Takami; Katsuhiko Sato

    2007-10-03

    We investigate the possibility that near future observations of ultra-high-energy cosmic rays (UHECRs) can unveil their local source distribution, which reflects the observed local structures if their origins are astrophysical objects. In order to discuss this possibility, we calculate the arrival distribution of UHE protons taking into account their propagation process in intergalactic space i.e. energy losses and deflections by extragalactic magnetic field (EGMF). For a realistic simulation, we construct and adopt a model of a structured EGMF and UHECR source distribution, which reproduce the local structures actually observed around the Milky Way. The arrival distribution is compared statistically to their source distribution using correlation coefficient. We specially find that UHECRs above $10^{19.8}$eV are best indicators to decipher their source distribution within 100 Mpc, and detection of about 500 events on all the sky allows us to unveil the local structure of UHE universe for plausible EGMF strength and the source number density. This number of events can be detected by five years observation by Pierre Auger Observatory.

  15. The Tunka Radio Extension (Tunka-Rex): Radio Measurements of Cosmic Rays in Siberia (PISA 2015)

    E-Print Network [OSTI]

    Schröder, F G; Budnev, N M; Gress, O A; Haungs, A; Hiller, R; Huege, T; Kazarina, Y; Kleifges, M; Konstantinov, E N; Korosteleva, E E; Kostunin, D; Krömer, O; Kuzmichev, L A; Lubsandorzhiev, N; Mirgazov, R R; Monkhoev, R; Pakhorukov, A; Pankov, L; Prosin, V V; Rubtsov, G I; Wischnewski, R; Zagorodnikov, A

    2015-01-01

    The Tunka observatory is located close to Lake Baikal in Siberia, Russia. Its main detector, Tunka-133, is an array of photomultipliers measuring Cherenkov light of air showers initiated by cosmic rays in the energy range of approximately $10^{16}-10^{18}\\,$eV. In the last years, several extensions have been built at the Tunka site, e.g., a scintillator array named Tunka-Grande, a sophisticated air-Cherenkov-detector prototype named HiSCORE, and the radio extension Tunka-Rex. Tunka-Rex started operation in October 2012 and currently features 44 antennas distributed over an area of about $3\\,$km$^2$, which measure the radio emission of the same air showers detected by Tunka-133 and Tunka-Grande. Tunka-Rex is a technological demonstrator that the radio technique can provide an economic extension of existing air-shower arrays. The main scientific goal is the cross-calibration with the air-Cherenkov measurements. By this cross-calibration, the precision for the reconstruction of the energy and mass of the primary...

  16. Cosmic Ray Confinement and Transport Models for Probing their Putative Sources

    E-Print Network [OSTI]

    Malkov, M A

    2015-01-01

    Recent efforts in cosmic ray (CR) confinement and transport theory are discussed. Three problems are addressed as being crucial for understanding the present day observations and their possible telltale signs of the CR origin. The first problem concerns CR behavior right after their release from a source, such as a supernova remnant (SNR). At this phase the CRs are confined near the source by self-emitted Alfven waves. The second is the problem of diffusive propagation of CRs through the turbulent ISM. This is a seemingly straightforward and long-resolved problem, but it remains controversial and reveals paradoxes. A resolution based on the Chapman-Enskog asymptotic CR transport analysis, that also includes magnetic focusing, is suggested. The third problem is about a puzzling sharp ($\\sim10^{\\circ}$) anisotropies in the CR arrival directions that might bear on important clues of their transport between the source and observer. The overarching goal is to improve our understanding of all aspects of the CR's so...

  17. Detailed numerical investigation of the Bohm limit in cosmic ray diffusion theory

    SciTech Connect (OSTI)

    Hussein, M.; Shalchi, A. E-mail: andreasm4@yahoo.com

    2014-04-10

    A standard model in cosmic ray diffusion theory is the so-called Bohm limit in which the particle mean free path is assumed to be equal to the Larmor radius. This type of diffusion is often employed to model the propagation and acceleration of energetic particles. However, recent analytical and numerical work has shown that standard Bohm diffusion is not realistic. In the present paper, we perform test-particle simulations to explore particle diffusion in the strong turbulence limit in which the wave field is much stronger than the mean magnetic field. We show that there is indeed a lower limit of the particle mean free path along the mean field. In this limit, the mean free path is directly proportional to the unperturbed Larmor radius like in the traditional Bohm limit, but it is reduced by the factor ?B/B {sub 0} where B {sub 0} is the mean field and ?B the turbulent field. Although we focus on parallel diffusion, we also explore diffusion across the mean field in the strong turbulence limit.

  18. Earth X-ray albedo for cosmic X-ray background radiation in the 1--1000 keV band

    E-Print Network [OSTI]

    E. Churazov; S. Sazonov; R. Sunyaev; M. Revnivtsev

    2008-02-11

    We present calculations of the reflection of the cosmic X-ray background (CXB) by the Earth's atmosphere in the 1--1000 keV energy range. The calculations include Compton scattering and X-ray fluorescent emission and are based on a realistic chemical composition of the atmosphere. Such calculations are relevant for CXB studies using the Earth as an obscuring screen (as was recently done by INTEGRAL). The Earth's reflectivity is further compared with that of the Sun and the Moon -- the two other objects in the Solar system subtending a large solid angle on the sky, as needed for CXB studies.

  19. A celestial gamma-ray foreground due to the albedo of small solar system bodies and a remote probe of the interstellar cosmic ray spectrum

    SciTech Connect (OSTI)

    Moskalenko, Igor V.; Porter, Troy A.; Digel, Seth W.; Michelson, Peter F.; Ormes, Jonathan F.

    2007-12-17

    We calculate the {gamma}-ray albedo flux from cosmic-ray (CR) interactions with the solid rock and ice in Main Belt asteroids and Kuiper Belt objects (KBOs) using the Moon as a template. We show that the {gamma}-ray albedo for the Main Belt and Kuiper Belt strongly depends on the small-body mass spectrum of each system and may be detectable by the forthcoming Gamma Ray Large Area Space Telescope (GLAST). The orbits of the Main Belt asteroids and KBOs are distributed near the ecliptic, which passes through the Galactic center and high Galactic latitudes. If detected, the {gamma}-ray emission by the Main Belt and Kuiper Belt has to be taken into account when analyzing weak {gamma}-ray sources close to the ecliptic, especially near the Galactic center and for signals at high Galactic latitudes, such as the extragalactic {gamma}-ray emission. Additionally, it can be used to probe the spectrum of CR nuclei at close-to-interstellar conditions, and the mass spectrum of small bodies in the Main Belt and Kuiper Belt. The asteroid albedo spectrum also exhibits a 511 keV line due to secondary positrons annihilating in the rock. This may be an important and previously unrecognized celestial foreground for the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) observations of the Galactic 511 keV line emission including the direction of the Galactic center.

  20. The IceCube Collaboration:contributions to the 30 th International Cosmic Ray Conference (ICRC 2007),

    SciTech Connect (OSTI)

    IceCube Collaboration; Ackermann, M.

    2007-11-02

    This paper bundles 40 contributions by the IceCube collaboration that were submitted to the 30th International Cosmic Ray Conference ICRC 2007. The articles cover studies on cosmic rays and atmospheric neutrinos, searches for non-localized, extraterrestrial {nu}{sub e}, {nu}{sub {mu}} and {nu}{sub {tau}} signals, scans for steady and intermittent neutrino point sources, searches for dark matter candidates, magnetic monopoles and other exotic particles, improvements in analysis techniques, as well as future detector extensions. The IceCube observatory will be finalized in 2011 to form a cubic-kilometer ice-Cherenkov detector at the location of the geographic South Pole. At the present state of construction, IceCube consists of 52 paired IceTop surface tanks and 22 IceCube strings with a total of 1426 Digital Optical Modules deployed at depths up to 2350 m. The observatory also integrates the 19 string AMANDA subdetector, that was completed in 2000 and extends IceCube's reach to lower energies. Before the deployment of IceTop, cosmic air showers were registered with the 30 station SPASE-2 surface array. IceCube's low noise Digital Optical Modules are very reliable, show a uniform response and record waveforms of arriving photons that are resolvable with nanosecond precision over a large dynamic range. Data acquisition, reconstruction and simulation software are running in production mode and the analyses, profiting from the improved data quality and increased overall sensitivity, are well under way.

  1. Investigation of the relative abundance of heavy versus light nuclei in primary cosmic rays using underground muon bundles

    SciTech Connect (OSTI)

    Sundaralingam, N.

    1993-06-08

    We study multiple muon events (muon bundles) recorded underground at a depth of 2090 mwe. To penetrate to this depth, the muons must have energies above 0.8 TeV at the Earth`s surface; the primary cosmic ray nuclei which give rise to the observed muon bundles have energies at incidence upon the upper atmosphere of 10 to 10{sup 5}TeV. The events are detected using the Soudan 2 experiment`s fine grained tracking calorimeter which is surrounded by a 14 m {times}10 m {times} 31 m proportional tube array (the ``active shield``). Muon bundles which have at least one muon traversing the calorimeter, are reconstructed using tracks in the calorimeter together with hit patterns in the proportional tube shield. All ionization pulses are required to be coincident within 3 microseconds. A goal of this study is to investigate the relative nuclear abundances in the primary cosmic radiation around the ``knee`` region (10{sup 3} {minus} 10{sup 4} TeV) of the incident energy spectrum. Four models for the nuclear composition of cosmic rays are considered: The Linsley model, the Constant Mass Composition model (CMC), the Maryland model and the Proton-poor model. A Monte Carlo which incorporates one model at a time is used to simulate events which are then reconstructed using the same computer algorithms that are used for the data. Identical cuts and selections are applied to the data and to the simulated events.

  2. COSMIC RAYS CAN DRIVE STRONG OUTFLOWS FROM GAS-RICH HIGH-REDSHIFT DISK GALAXIES

    SciTech Connect (OSTI)

    Hanasz, M.; Kowalik, K.; Wólta?ski, D. [Centre for Astronomy, Nicolaus Copernicus University, Faculty of Physics, Astronomy and Informatics, Grudziadzka 5, PL-87100 Toru? (Poland)] [Centre for Astronomy, Nicolaus Copernicus University, Faculty of Physics, Astronomy and Informatics, Grudziadzka 5, PL-87100 Toru? (Poland); Lesch, H. [Universitäts-Sternwarte München, Scheinerstr. 1, D-81679 München (Germany)] [Universitäts-Sternwarte München, Scheinerstr. 1, D-81679 München (Germany); Naab, T. [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, D-85741 Garching bei München (Germany)] [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, D-85741 Garching bei München (Germany); Gawryszczak, A., E-mail: mhanasz@astri.uni.torun.pl [Pozna? Supercomputing and Networking Centre, ul. Noskowskiego 10, PL-61-704 Pozna? (Poland)

    2013-11-10

    We present simulations of the magnetized interstellar medium (ISM) in models of massive star-forming (40 M {sub ?} yr{sup –1}) disk galaxies with high gas surface densities (?{sub gas} ? 100 M {sub ?} pc{sup –2}) similar to observed star-forming high-redshift disks. We assume that type II supernovae deposit 10% of their energy into the ISM as cosmic rays (CRs) and neglect the additional deposition of thermal energy or momentum. With a typical Galactic diffusion coefficient for CRs (3 × 10{sup 28} cm{sup 2} s{sup –1}), we demonstrate that this process alone can trigger the local formation of a strong low-density galactic wind maintaining vertically open field lines. Driven by the additional pressure gradient of the relativistic fluid, the wind speed can exceed 10{sup 3} km s{sup –1}, much higher than the escape velocity of the galaxy. The global mass loading, i.e., the ratio of the gas mass leaving the galactic disk in a wind to the star formation rate, becomes of order unity once the system has settled into an equilibrium. We conclude that relativistic particles accelerated in supernova remnants alone provide a natural and efficient mechanism to trigger winds similar to observed mass-loaded galactic winds in high-redshift galaxies. These winds also help in explaining the low efficiencies for the conversion of gas into stars in galaxies, as well as the early enrichment of the intergalactic medium with metals. This mechanism may be at least of similar importance to the traditionally considered momentum feedback from massive stars and thermal and kinetic feedback from supernova explosions.

  3. The cosmic-ray ground-level enhancement of 1989 September 29

    SciTech Connect (OSTI)

    Moraal, H. [Centre for Space Research, School for Physical and Chemical Sciences, North-West University, Potchefstroom 2520 (South Africa); Caballero-Lopez, R. A. [Ciencias Espaciales, Instituto de Geofisica, Universidad Nacional Autónoma de México, 04510 México D.F. (Mexico)

    2014-08-01

    The ground-level enhancement (GLE) of 1989 September 29 is one of the largest of 71 solar energetic particle events observed by neutron monitors on Earth. It was smaller than the record-breaking GLE 5 of 1956 February 23, but by some measures it was larger than GLE 69 of 2005 January 20. It is also the most extensively studied of the 71 GLEs, and it was observed by more than 50 ground-based detectors in the worldwide network. This paper contains another study of the event, with the main difference from previous studies that all the existing observations are employed, instead of the usual selection of stations. An effort is made to represent all the information graphically. This reveals new insight in the event, mainly about its time profile. The main conclusion is that the event is the best example available of a 'classical' GLE that has a gradual increase toward peak intensity and does not contain two or more distinct peaks as inferred previously. It does, however, suggest that there were two acceleration or release mechanisms: a prompt, rapid one and a delayed, slower one. This conclusion is based on a detailed comparison with GLE 69 of 2005 January 20, which is the best-known example of a double-peaked event with a 'prompt' component. It is also found that the rigidity spectrum was probably softer than derived in several previous studies, and that the decay phase of the event reveals that the cosmic-ray diffusion coefficient in the neutron monitor range is proportional to rigidity.

  4. Magnetic lensing of extremely high energy cosmic rays in a galactic wind

    E-Print Network [OSTI]

    Diego Harari; Silvia Mollerach; Esteban Roulet

    2000-05-24

    We show that in the model of Galactic magnetic wind recently proposed to explain the extremely high energy (EHE) cosmic rays so far observed as originating from a single source (M87 in the Virgo cluster), the magnetic field strongly magnifies the fluxes and produces multiple images of the source. The apparent position on Earth of the principal image moves, for decreasing energies, towards the galactic south. It is typically amplified by an order of magnitude at $E/Z\\sim 2\\times 10^{20}$ eV, but becomes strongly demagnified below $10^{20}$ eV. At energies below $E/Z\\sim 1.3\\times 10^{20}$ eV, all events in the northern galactic hemisphere are due to secondary images, which have huge amplifications ($>10^2$). This model would imply strong asymmetries between the north and south galactic hemispheres, such as a (latitude dependent) upper cut-off value below $2\\times 10^{20}$ eV for CR protons arriving to the south and lower fluxes in the south than in the north above $10^{20}$ eV. The large resulting magnifications reduce the power requirements on the source, but the model needs a significant tunning between the direction to the source and the symmetry axis of the wind. If more modest magnetic field strengths were assumed, a scenario in which the observed EHE events are heavier nuclei whose flux is strongly lensed becomes also plausible and would predict that a transition from a light composition to a heavier one could take place at the highest energies.

  5. Ultra High Energy Cosmic Ray and UHE Neutrino-Z Showering in Dark Halos

    E-Print Network [OSTI]

    Daniele Fargion; P. G. De Sanctis Lucentini; M. Grossi; M. De Santis; Barbara Mele

    2002-01-03

    The Ultra High Energy Cosmic Ray (UHECR), by UHE neutrino-relic neutrino--Z showering in Hot Dark Halos (HDM), shows an energy spectra, an anisotropy following the relic neutrino masses and clustering in dark halo. The lighter are the relic neutrinos masses, the higher their corresponding Z resonance energy peaks. A twin light neutrino mass splitting may reflect into a twin Z resonance and a complex UHECR spectra modulation as a twin bump at at highest GZK energy cut-off. Each possible neutrino mass associates a characteristic dark halo size (galactic, local, super cluster) and its anisotropy due to our peculiar position within that dark matter distribution. The expected Z or WW,ZZ showering into proton-anti proton and neutron-anti neutron might correspond to peculiar clustering in observed UHECR at 10^{19}, 2 10^{19}, 4 10^{19} eV. A neutrino light HDM halo around a Mpc will allow to the UHECR neutron--anti-neutron secondary component at E_n> 10^{20} eV (due to Z decay) to arise playing a role comparable with the charged p-bar{p} ones. Their un-deflected n-bar{n} flight is shorter leading to a prompt and hard UHECR trace pointing toward the original UHECR source direction. The direct proton-antiproton pairs are split and spread by random magnetic fields into a more diluted and smeared and lower energy UHECR signal around the original source direction. Additional prompt TeVs signals by synchrotron radiation of electro-magnetic Z showering must also occur solving the Infrared-TeV cut-off. The observed hard doublet and triplets spectra, their time and space clustering already favour the rising key role of UHECR n-bar n secondaries originated by neutrino-Z tail shower.

  6. The coherent acceleration of ultra high energy cosmic rays and the galactic dynamo

    SciTech Connect (OSTI)

    Colgate, S.A.

    1995-05-01

    In order to accelerate cosmic rays to ultra high energy, >10{sup 18} ev, requires that the step size in energy in a diffusive process be very much larger than occurs in galactic or extra galactic hydrodynamic mechanisms where {Delta}E/F {approximately} v/c{approximately}1/300 per step. This step size requires >10{sup 5} scatterings per doubling in energy (the shock mechanism) and therefore <10{sup {minus}5} energy loss per scattering. Coherent acceleration (CA), on the other hand, is proposed in which the energy gained, {Delta}E per particle in the CA region is very much larger so that only one or several scatterings are required to reach the final energy. The power law spectrum is created by the probability of loss from the CA region where this probability is inversely proportional to the particle`s rigidity, E. Therefore the fractional loss in number per fractional gain in energy, dN/N {approximately} {minus}{Gamma} dE/E, results in a power law spectrum. CA depends upon the electric field, E = {eta}J, J, the current density, in a force free field, where magnetic helicity, J={alpha}B, arises universally in all evolving mass condensations due to twisting of magnetic flux by the large number of turns before pressure support. The acceleration process is E*v, where universe beam instabilities enhance {eta} leading to phased coherent acceleration (PCA). The result of the energy transfer from field energy to matter energy is the relaxation of the field helicity, or reconnection but with J{parallel}B rather than J{perpendicular}B.

  7. Gamma-Rays from Large Scale Structure Formation and the Warm-Hot Intergalactic Medium: Cosmic Baryometry with Gamma-Rays

    E-Print Network [OSTI]

    Susumu Inoue; Masahiro Nagashima

    2005-02-17

    It is shown that inverse Compton gamma-rays from electrons accelerated in large scale structure formation shocks can be crucially affected by non-gravitational effects such as radiative cooling and galaxy formation, with corresponding uncertainties by an order of magnitude in either the gamma-ray source counts or the extragalactic background contribution. However, this also implies that such gamma-rays may in the near future provide us with valuable information about the fraction of cosmic baryons in different forms, particularly the warm-hot intergalactic medium where the majority of the baryons in the universe are believed to reside. We address this problem in a simple way through semi-analytic modeling of structure formation shocks which self-consistently treats merger and accretion shocks.

  8. Searches for anisotropies in the arrival directions of the highest energy cosmic rays detected by the Pierre Auger Observatory

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Samarai, I. Al; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; et al

    2015-04-24

    In this study, we analyze the distribution of arrival directions of ultra-high-energy cosmic rays recorded at the Pierre Auger Observatory in 10 years of operation. The data set, about three times larger than that used in earlier studies, includes arrival directions with zenith angles up to 80°, thus covering from $-90{}^\\circ $ to $+45{}^\\circ $ in declination. After updating the fraction of events correlating with the active galactic nuclei (AGNs) in the Véron-Cetty and Véron catalog, we subject the arrival directions of the data with energies in excess of 40 EeV to different tests for anisotropy. We search for localizedmore »excess fluxes, self-clustering of event directions at angular scales up to 30°, and different threshold energies between 40 and 80 EeV. We then look for correlations of cosmic rays with celestial structures both in the Galaxy (the Galactic Center and Galactic Plane) and in the local universe (the Super-Galactic Plane). We also examine their correlation with different populations of nearby extragalactic objects: galaxies in the 2MRS catalog, AGNs detected by Swift-BAT, radio galaxies with jets, and the Centaurus A (Cen A) galaxy. None of the tests show statistically significant evidence of anisotropy. The strongest departures from isotropy (post-trial probability $\\sim 1.4$%) are obtained for cosmic rays with $E\\gt 58$ EeV in rather large windows around Swift AGNs closer than 130 Mpc and brighter than 1044 erg/s (18° radius), and around the direction of Centaurus A (15° radius).« less

  9. Searches for anisotropies in the arrival directions of the highest energy cosmic rays detected by the Pierre Auger Observatory

    SciTech Connect (OSTI)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Samarai, I. Al; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Castillo, J. Alvarez; Alvarez-Muńiz, J.; Batista, R. Alves; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Aranda, V. M.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Awal, N.; Badescu, A. M.; Barber, K. B.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blaess, S. G.; Blanco, M.; Bleve, C.; Blümer, H.; Bohá?ová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Bridgeman, A.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceiçăo, R.; Contreras, F.; Cooper, M. J.; Cordier, A.; Coutu, S.; Covault, C. E.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; Almeida, R. M. de; Domenico, M. De; Jong, S. J. de; Neto, J. R. T. de Mello; Mitri, I. De; Oliveira, J. de; Souza, V. de; Peral, L. del; Deligny, O.; Dembinski, H.; Dhital, N.; Giulio, C. Di; Matteo, A. Di; Diaz, J. C.; Castro, M. L. Díaz; Diogo, F.; Dobrigkeit, C.; Docters, W.; D’Olivo, J. C.; Dorofeev, A.; Hasankiadeh, Q. Dorosti; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Luis, P. Facal San; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fernandes, M.; Fick, B.; Figueira, J. M.; Filevich, A.; Filip?i?, A.; Fox, B. D.; Fratu, O.; Freire, M. M.; Fröhlich, U.; Fuchs, B.; Fujii, T.; Gaior, R.; García, B.; Gamez, D. Garcia-; Pinto, D. Garcia-; Garilli, G.; Bravo, A. Gascon; Gate, F.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Glaser, C.; Glass, H.; Berisso, M. Gómez; Vitale, P. F. Gómez; Gonçalves, P.; Gonzalez, J. G.; González, N.; Gookin, B.; Gordon, J.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Hartmann, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Jandt, I.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Krömer, O.; Hansen, D. Kruppke-; Kuempel, D.; Kunka, N.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Coz, S. Le; Leăo, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Louedec, K.; Bahilo, J. Lozano; Lu, L.; Lucero, A.; Ludwig, M.; Malacari, M.; Maldera, S.; Mallamaci, M.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Mari?, I. C.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Bravo, O. Martínez; Martraire, D.; Meza, J. J. Masías; Mathes, H. J.; Mathys, S.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Tanco, G. Medina-; Meissner, R.; Melissas, M.; Melo, D.; Menshikov, A.; Messina, S.; Meyhandan, R.; Mi?anovi?, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Bueno, L. Molina-; Mollerach, S.; Monasor, M.; Ragaigne, D. Monnier; Montanet, F.; Morello, C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Müller, S.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nguyen, P. H.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, L.; Ochilo, L.; Oikonomou, F.; Olinto, A.; Oliveira, M.; Pacheco, N.; Dei, D. Pakk Selmi-; Palatka, M.; Pallotta, J.; Palmieri, N.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; P?kala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Petermann, E.; Peters, C.; Petrera, S.; Petrov, Y.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porcelli, A.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Purrello, V.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.

    2015-04-24

    In this study, we analyze the distribution of arrival directions of ultra-high-energy cosmic rays recorded at the Pierre Auger Observatory in 10 years of operation. The data set, about three times larger than that used in earlier studies, includes arrival directions with zenith angles up to 80°, thus covering from $-90{}^\\circ $ to $+45{}^\\circ $ in declination. After updating the fraction of events correlating with the active galactic nuclei (AGNs) in the Véron-Cetty and Véron catalog, we subject the arrival directions of the data with energies in excess of 40 EeV to different tests for anisotropy. We search for localized excess fluxes, self-clustering of event directions at angular scales up to 30°, and different threshold energies between 40 and 80 EeV. We then look for correlations of cosmic rays with celestial structures both in the Galaxy (the Galactic Center and Galactic Plane) and in the local universe (the Super-Galactic Plane). We also examine their correlation with different populations of nearby extragalactic objects: galaxies in the 2MRS catalog, AGNs detected by Swift-BAT, radio galaxies with jets, and the Centaurus A (Cen A) galaxy. None of the tests show statistically significant evidence of anisotropy. The strongest departures from isotropy (post-trial probability $\\sim 1.4$%) are obtained for cosmic rays with $E\\gt 58$ EeV in rather large windows around Swift AGNs closer than 130 Mpc and brighter than 1044 erg/s (18° radius), and around the direction of Centaurus A (15° radius).

  10. Study of cosmic ray events with high muon multiplicity using the ALICE detector at the CERN Large Hadron Collider

    E-Print Network [OSTI]

    ALICE Collaboration

    2015-07-27

    ALICE is one of four large experiments at the CERN Large Hadron Collider near Geneva, specially designed to study particle production in ultra-relativistic heavy-ion collisions. Located 52 meters underground with 28 meters of overburden rock, it has also been used to detect muons produced by cosmic ray interactions in the upper atmosphere. In this paper, we present the multiplicity distribution of these atmospheric muons and its comparison with Monte Carlo simulations. This analysis exploits the large size and excellent tracking capability of the ALICE Time Projection Chamber. A special emphasis is given to the study of high multiplicity events containing more than 100 reconstructed muons and corresponding to a muon areal density $\\rho_{\\mu} > 5.9~$m$^{-2}$. Similar events have been studied in previous underground experiments such as ALEPH and DELPHI at LEP. While these experiments were able to reproduce the measured muon multiplicity distribution with Monte Carlo simulations at low and intermediate multiplicities, their simulations failed to describe the frequency of the highest multiplicity events. In this work we show that the high multiplicity events observed in ALICE stem from primary cosmic rays with energies above $10^{16}$ eV and that the frequency of these events can be successfully described by assuming a heavy mass composition of primary cosmic rays in this energy range. The development of the resulting air showers was simulated using the latest version of QGSJET to model hadronic interactions. This observation places significant constraints on alternative, more exotic, production mechanisms for these events.

  11. A hadronic-leptonic model for the Fermi bubbles: Cosmic-rays in the galactic halo and radio emission

    SciTech Connect (OSTI)

    Fujita, Yutaka; Ohira, Yutaka; Yamazaki, Ryo

    2014-07-01

    We investigate non-thermal emission from the Fermi bubbles in a hadronic model. Cosmic-ray (CR) protons are accelerated at the forward shock of the bubbles. They interact with the background gas in the Galactic halo and create ?{sup 0}-decay gamma-rays and secondary electrons through proton-proton interaction. We follow the evolution of the CR protons and electrons by calculating their distribution functions. We find that the spectrum and the intensity profiles of ?{sup 0}-decay gamma-rays are consistent with observations. We predict that the shock front is located far ahead of the gamma-ray boundary of the Fermi bubbles. This naturally explains the fact that a clear temperature jump of thermal gas was not discovered at the gamma-ray boundary in recent Suzaku observations. We also consider re-acceleration of the background CRs in the Galactic halo at the shock front. We find that it can significantly affect the gamma-rays from the Fermi bubbles, unless the density of the background CRs is ? 10% of that in the Galactic disk. We indicate that secondary electrons alone cannot produce the observed radio emission from the Fermi bubbles. However, the radio emission from the outermost region of the bubbles can be explained if electrons are directly accelerated at the shock front with an efficiency of ?0.1% of that of protons.

  12. Local H~{\\sc i} emissivity measured with the {\\it Fermi}-LAT and implications for cosmic-ray spectra

    E-Print Network [OSTI]

    Casandjian, Jean-Marc

    2015-01-01

    Cosmic-ray (CR) electrons and nuclei interact with the Galactic interstellar gas and produce high-energy $\\gamma$ rays. The $\\gamma$-ray emission rate per hydrogen atom, called emissivity, provides a unique indirect probe of the CR flux. We present the measurement and the interpretation of the emissivity in the solar neighborhood for $\\gamma$-ray energy from 50~MeV to 50~GeV. We analyzed a subset of 4 years of observations from the Large Area Telescope (LAT) aboard the {\\it Fermi Gamma-ray Space Telescope} ({\\it Fermi}) restricted to absolute latitudes $10^ohydrogen column density templates as well as a dust optical depth map we derived the emissivities, the molecular hydrogen to CO conversion factor $X_{CO}=(0.902\\pm0.007) \\times 10^{20}$ cm$^{-2}$ (K km s$^{-1}$)$^{-1}$ and the dust-to-gas ratio $X_{DUST}=(41.4\\pm0.3) \\times 10^{20}$ cm$^{-2}$ mag$^{-1}$. Moreover we detected for the first time $\\gamma$-ray emission from i...

  13. High-Energy Cosmic-Ray Muons Under Thick Layers of Matter I. a Method to Solve the Transport Equation

    E-Print Network [OSTI]

    V. A. Naumov; S. I. Sinegovsky; E. V. Bugaev

    1993-01-22

    An effective analytical method for calculating energy spectra of cosmic-ray muons at large depths of homogeneous media is developed. The method allows to include an arbitrary (decreasing) muon spectrum at the medium boundary and the energy dependence of both discrete (radiative and photonuclear) and continuous (ionization) muon energy losses, with resonable requirements for the high-energy behavior of the initial spectrum and differential cross sections of the muon-matter interactions. (To be published in the Proceedings of the Second NESTOR International Workshop, 19 -- 21 October 1992, Pylos, Greece.)

  14. The Microwave Air Yield Beam Experiment (MAYBE): measurement of GHz radiation for Ultra-High Energy Cosmic Rays detection

    E-Print Network [OSTI]

    M. Monasor; M. Bohacova; C. Bonifazi; G. Cataldi; S. Chemerisov; J. R. T. De Mello Neto; P. Facal San Luis; B. Fox; P. W. Gorham; C. Hojvat; N. Hollon; R. Meyhandan; L. C. Reyes; B. Rouille D'Orfeuil; E. M. Santos; J. Pochez; P. Privitera; H. Spinka; V. Verzi; C. Williams; J. Zhou

    2011-08-31

    We present first measurements by MAYBE of microwave emission from an electron beam induced air plasma, performed at the electron Van de Graaff facility of the Argonne National Laboratory. Coherent radio Cherenkov, a major background in a previous beam experiment, is not produced by the 3 MeV beam, which simplifies the interpretation of the data. Radio emission is studied over a wide range of frequencies between 3 and 12 GHz. This measurement provides further insight on microwave emission from extensive air showers as a novel detection technique for Ultra-High Energy Cosmic Rays.

  15. A Measurement of the Flux of Cosmic Ray Iron at 5 x 10^13 eV

    E-Print Network [OSTI]

    J. Clem; W. Droege; P. A. Evenson; H. Fischer; G. Green; D. Huber; H. Kunow; D. Seckel

    2001-03-23

    We present results from the initial flight of our Balloon Air CHerenkov (BACH) payload. BACH detects air Cherenkov radiation from cosmic ray nuclei as coincident flashes in two optical modules. The flight (dubbed PDQ BACH) took place on April 22, 1998 from Ft. Sumner, New Mexico. During an exposure of 2.75 hours, with a typical threshold energy for iron nuclei of 2.2$\\times10^{13}$ eV, we observed several events cleanly identifiable as iron group nuclei. Analysis of the data yields a new flux measurement that is fully consistent with that reported by other investigations.

  16. Signatures of Ultra-High Energy Cosmic Ray Composition from Propagation of Nuclei in Intergalactic Photon Fields

    E-Print Network [OSTI]

    Tokonatsu Yamamoto; Keiichi Mase; Masahiro Takeda; Naoto Sakaki; Masahiro Teshima

    2003-12-10

    We present a calculation of nuclei propagation with energies above 1 EeV in the intergalactic photon field. The calculation is based on a Monte Carlo approach for the nucleus-photon interaction as well as the intergalactic magnetic field. We then assume that the Ultra-High Energy Cosmic Rays are nuclei which are emitted from extra-galactic point sources. Four bumps are found in the energy spectrum of the UHECR which form clusters in the distribution of their arrival directions. Based on this calculation, the energy distribution of the clustered events is discussed.

  17. A Prototype PCI-based Data Acquisition System for Cosmic Ray Detection Below 10^18 eV

    E-Print Network [OSTI]

    Ben-Zvi, S Y; Bán, J; Sippach, W

    2006-01-01

    A prototype flash analog-to-digital readout system for cosmic ray detection at energies below 10^18 eV has been designed and tested at Columbia University Nevis Laboratories. The electronics consist of an FADC module that digitizes 16 photomultipliers at 40 MHz with 14-bit dynamic range. The module is read out to a PC (running Linux) through a PCI interface. Taking advantage of the large bandwidth provided by the PCI bus, we have implemented a software-based data acquisition system. This note describes the software and electronics, as well as preliminary tests carried out using a prototype FADC module.

  18. A Prototype PCI-based Data Acquisition System for Cosmic Ray Detection Below 10^18 eV

    E-Print Network [OSTI]

    S. BenZvi; S. Westerhoff; J. Ban; W. Sippach

    2006-03-28

    A prototype flash analog-to-digital readout system for cosmic ray detection at energies below 10^18 eV has been designed and tested at Columbia University Nevis Laboratories. The electronics consist of an FADC module that digitizes 16 photomultipliers at 40 MHz with 14-bit dynamic range. The module is read out to a PC (running Linux) through a PCI interface. Taking advantage of the large bandwidth provided by the PCI bus, we have implemented a software-based data acquisition system. This note describes the software and electronics, as well as preliminary tests carried out using a prototype FADC module.

  19. Physical conditions in potential sources of ultra-high-energy cosmic rays: Updated Hillas plot and radiation-loss constraints

    E-Print Network [OSTI]

    Ksenia Ptitsyna; Sergey Troitsky

    2010-03-26

    We review basic constraints on the acceleration of ultra-high-energy (UHE) cosmic rays (CRs) in astrophysical sources, namely the geometrical (Hillas) criterion and restrictions from radiation losses in different acceleration regimes. Using the latest available astrophysical data, we redraw the Hillas plot and figure out potential UHECR accelerators. For the acceleration in central engines of active galactic nuclei, we constrain the maximal UHECR energy for a given black-hole mass. Among active galaxies, only the most powerful ones, radio galaxies and blazars, are able to accelerate protons to UHE, though acceleration of heavier nuclei is possible in much more abundant lower-power Seyfert galaxies.

  20. Origin of Cosmic Radiation

    E-Print Network [OSTI]

    Thomas K. Gaisser

    2000-11-28

    I give a brief overview of cosmic ray physics, highlighting some key questions and how they will be addressed by new experiments.

  1. LARGE-SCALE DISTRIBUTION OF ARRIVAL DIRECTIONS OF COSMIC RAYS DETECTED ABOVE 10{sup 18} eV AT THE PIERRE AUGER OBSERVATORY

    SciTech Connect (OSTI)

    Abreu, P.; Andringa, S.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muniz, J.; Alves Batista, R.; Ambrosio, M.; Aramo, C.; Aminaei, A.; Anchordoqui, L.; Antici'c, T.; Arganda, E.; Collaboration: Pierre Auger Collaboration; and others

    2012-12-15

    A thorough search for large-scale anisotropies in the distribution of arrival directions of cosmic rays detected above 10{sup 18} eV at the Pierre Auger Observatory is presented. This search is performed as a function of both declination and right ascension in several energy ranges above 10{sup 18} eV, and reported in terms of dipolar and quadrupolar coefficients. Within the systematic uncertainties, no significant deviation from isotropy is revealed. Assuming that any cosmic-ray anisotropy is dominated by dipole and quadrupole moments in this energy range, upper limits on their amplitudes are derived. These upper limits allow us to test the origin of cosmic rays above 10{sup 18} eV from stationary Galactic sources densely distributed in the Galactic disk and predominantly emitting light particles in all directions.

  2. CONSTRAINTS ON THE ORIGIN OF COSMIC RAYS ABOVE 10{sup 18} eV FROM LARGE-SCALE ANISOTROPY SEARCHES IN DATA OF THE PIERRE AUGER OBSERVATORY

    SciTech Connect (OSTI)

    Abreu, P.; Andringa, S.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Castillo, J. Alvarez; Alvarez-Muniz, J.; Alves Batista, R.; Ambrosio, M.; Aramo, C.; Aminaei, A.; Anchordoqui, L.; Antici'c, T.; Arganda, E.; Collaboration: Pierre Auger Collaboration; and others

    2013-01-01

    A thorough search for large-scale anisotropies in the distribution of arrival directions of cosmic rays detected above 10{sup 18} eV at the Pierre Auger Observatory is reported. For the first time, these large-scale anisotropy searches are performed as a function of both the right ascension and the declination and expressed in terms of dipole and quadrupole moments. Within the systematic uncertainties, no significant deviation from isotropy is revealed. Upper limits on dipole and quadrupole amplitudes are derived under the hypothesis that any cosmic ray anisotropy is dominated by such moments in this energy range. These upper limits provide constraints on the production of cosmic rays above 10{sup 18} eV, since they allow us to challenge an origin from stationary galactic sources densely distributed in the galactic disk and emitting predominantly light particles in all directions.

  3. The Energy Spectrum of Cosmic Rays above 10$^{17.2}$ eV Measured by the Fluorescence Detectors of the Telescope Array Experiment in Seven Years

    E-Print Network [OSTI]

    ,

    2015-01-01

    The Telescope Array (TA) experiment is the largest detector to observe ultra-high-energy cosmic rays in the northern hemisphere. The fluorescence detectors at southern two stations of TA are newly constructed and have now completed seven years of steady operation. One advantage of monocular analysis of the fluorescence detectors is a lower energy threshold for cosmic rays than that of other techniques like stereoscopic observations or coincidences with the surface detector array, allowing the measurement of an energy spectrum covering three orders of magnitude in energy. Analyzing data collected during those seven years, we report the energy spectrum of cosmic rays covering a broad range of energies above 10$^{17.2}$ eV measured by the fluorescence detectors and a comparison with previously published results.

  4. Tracing the propagation of cosmic rays in the Milky Way halo with Fermi-LAT observations of high- and intermediate-velocity clouds

    E-Print Network [OSTI]

    Tibaldo, L

    2015-01-01

    Cosmic rays up to at least PeV energies are usually described in the framework of an elementary scenario that involves acceleration by objects that are located in the disk of the Milky Way, such as supernova remnants or massive star-forming regions, and then diffusive propagation throughout the Galaxy. Details of the propagation process are so far inferred mainly from the composition of cosmic rays measured near the Earth and then extrapolated to the whole Galaxy. The details of the propagation in the Galactic halo and the escape into the intergalactic medium remain uncertain. The densities of cosmic rays in specific locations can be traced via the gamma rays they produce in inelastic collisions with clouds of interstellar gas. Therefore, we analyze 73 months of Fermi-LAT data from 300 MeV to 10 GeV in the direction of several high- and intermediate-velocity clouds that are located in the halo of the Milky Way. These clouds are supposed to be free of internal sources of cosmic rays and hence any gamma-ray emi...

  5. A study of the link between cosmic rays and clouds with a cloud chamber at the CERN PS

    E-Print Network [OSTI]

    The Cloud Collaboration

    2001-04-16

    Recent satellite data have revealed a surprising correlation between galactic cosmic ray (GCR) intensity and the fraction of the Earth covered by clouds. If this correlation were to be established by a causal mechanism, it could provide a crucial step in understanding the long-sought mechanism connecting solar and climate variability. The Earth's climate seems to be remarkably sensitive to solar activity, but variations of the Sun's electromagnetic radiation appear to be too small to account for the observed climate variability. However, since the GCR intensity is strongly modulated by the solar wind, a GCR-cloud link may provide a sufficient amplifying mechanism. Moreover if this connection were to be confirmed, it could have profound consequences for our understanding of the solar contributions to the current global warming. The CLOUD (Cosmics Leaving OUtdoor Droplets) project proposes to test experimentally the existence a link between cosmic rays and cloud formation, and to understand the microphysical mechanism. CLOUD plans to perform detailed laboratory measurements in a particle beam at CERN, where all the parameters can be precisely controlled and measured. The beam will pass through an expansion cloud chamber and a reactor chamber where the atmosphere is to be duplicated by moist air charged with selected aerosols and trace condensable vapours. An array of external detectors and mass spectrometers is used to analyse the physical and chemical characteristics of the aerosols and trace gases during beam exposure. Where beam effects are found, the experiment will seek to evaluate their significance in the atmosphere by incorporating them into aerosol and cloud models.

  6. The star-forming galaxy contribution to the cosmic MeV and GeV gamma-ray background

    SciTech Connect (OSTI)

    Lacki, Brian C. [Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States); Horiuchi, Shunsaku [Center for Cosmology, Department of Physics and Astronomy, 4129 Frederick Reines Hall, University of California, Irvine, CA 92697-4575 (United States); Beacom, John F., E-mail: brianlacki@ias.edu [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)

    2014-05-01

    Star-forming galaxies could be major contributors to the cosmic GeV ?-ray background, and they are expected to be MeV-dim because of the 'pion bump' falling off below ?100 MeV. However, there are very few observations of galaxies in the MeV range and other emission processes could be present. We investigate the MeV background from star-forming galaxies by running one-zone models of cosmic ray populations, including inverse Compton and bremsstrahlung, as well as nuclear lines (including {sup 26}Al), emission from core-collapse supernovae, and positron annihilation emission, in addition to the pionic emission. We use the Milky Way and M82 as templates of normal and starburst galaxies and compare our models to radio and GeV-TeV ?-ray data. We find that (1) higher gas densities in high-z normal galaxies lead to a strong pion bump, (2) starbursts may have significant MeV emission if their magnetic field strengths are low, and (3) cascades can contribute to the MeV emission of starbursts if they emit mainly hadronic ?-rays. Our fiducial model predicts that most of the unresolved GeV background is from star-forming galaxies, but this prediction is uncertain by an order of magnitude. About ?2% of the claimed 1 MeV background is diffuse emission from star-forming galaxies; we place a firm upper limit of ? 10% based on the spectral shape of the background. The star formation contribution is constrained to be small because its spectrum is peaked, while the observed background is steeply falling with energy through the MeV-GeV range.

  7. Indirect and direct signatures of Higgs portal decaying vector dark matter for positron excess in cosmic rays

    SciTech Connect (OSTI)

    Baek, Seungwon; Ko, P.; Park, Wan-Il; Tang, Yong E-mail: pko@kias.re.kr E-mail: ytang@kias.re.kr

    2014-06-01

    We investigate the indirect signatures of the Higgs portal U(1){sub X} vector dark matter (VDM) X{sub ?} from both its pair annihilation and decay. The VDM is stable at renormalizable level by Z{sub 2} symmetry, and thermalized by Higgs-portal interactions. It can also decay by some nonrenormalizable operators with very long lifetime at cosmological time scale. If dim-6 operators for VDM decays are suppressed by 10{sup 16} GeV scale, the lifetime of VDM with mass ? 2 TeV is just right for explaining the positron excess in cosmic ray observed by PAMELA and AMS02 Collaborations. The VDM decaying into ?{sup +}?{sup ?} can fit the data, evading various constraints on cosmic rays. We give one UV-complete model as an example. This scenario for Higgs portal decaying VDM with mass around ? 2 TeV can be tested by DM direct search at XENON1T, and also at the future colliders by measuring the Higgs self-couplings.

  8. Downloaded 12 Feb 2013 to 217.83.179.81. Redistribution subject to AIP license or copyright; see http://proceedings.aip.org/about/rights_permissions The Composition of Cosmic Rays at the Knee

    E-Print Network [OSTI]

    Hörandel, Jörg R.

    to AIP license or copyright; see http://proceedings.aip.org/about/rights_permissions #12;Energy (GeV) 10Downloaded 12 Feb 2013 to 217.83.179.81. Redistribution subject to AIP license or copyright; see of cosmic rays in the energy region from about 1014 to 1018 eV are reviewed. Keywords: cosmic rays

  9. 28th International Cosmic Ray Conference 2133 A Second Level Trigger for PAMELA

    E-Print Network [OSTI]

    Morselli, Aldo

    of antimatter in the cosmic radiation. PAMELA comprises of a transition radiation detector, a permanent magnet scintillator read out by photomultiplier tubes. The CAS detectors surround the spectrometer (tracker and magnet, a simulation study has been performed. The simulations included protons of various energies generated

  10. On scaling cosmogenic nuclide production rates for altitude and latitude using cosmic-ray measurements

    E-Print Network [OSTI]

    Zreda, Marek

    On scaling cosmogenic nuclide production rates for altitude and latitude using cosmic 2001 Abstract The wide use of cosmogenic nuclides for dating terrestrial landforms has prompted for production rates of cosmogenic nuclides. Over the past 50 years, the overwhelming majority of nucleon flux

  11. Cosmic-ray results from IceCube/ Mumbai, 12/12/12 Tom Gaisser for the IceCube Collab. 1

    E-Print Network [OSTI]

    Gaisser, Thomas K.

    Cosmic-ray results from IceCube/ IceTop Mumbai, 12/12/12 Tom Gaisser for the IceCube Collab. 1 #12;Mumbai, 12/12/12 Tom Gaisser for the IceCube Collab. 2 events ­ IceTop/deep IceCube Mumbai, 12/12/12 Tom Gaisser for the IceCube Collab

  12. Constraints on the cosmic ray cluster physics from a very deep observation of the Perseus cluster with MAGIC

    E-Print Network [OSTI]

    Colin, Pierre; Acosta, Monica Vazquez; Pfrommer, Christoph; Pinzke, Anders

    2015-01-01

    Galaxy clusters are the largest and most massive gravitationally bound structures known in the Universe. Cosmic-Ray (CR) hadrons accelerated at structure formation shocks and injected by galaxies, are confined in galaxy clusters where they accumulate for cosmological times. The presence of diffuse synchrotron radio emission in several clusters proves the existence of high-energy electrons, and magnetic fields. However, a direct proof of CR proton acceleration is missing. The presence of CR protons can be probe through the diffuse gamma-ray emission induced by their hadronic interaction with the Intra-Cluster Medium (ICM). The Perseus cluster, a nearby cool-core cluster, has been identified to be among the best candidates to detect such emission. We present here the results of a very deep observation of the Perseus cluster with the MAGIC telescopes, accumulating about 250 hours of data from 2009 to 2014. No evidence of large-scale very-high-energy gamma-ray emission from CR-ICM interactions has been detected. ...

  13. Air Fluorescence Relevant for Cosmic-Ray Detection - Summary of the 5th Fluorescence Workshop, El Escorial 2007

    E-Print Network [OSTI]

    Fernando Arqueros; Joerg R. Hoerandel; Bianca Keilhauer

    2008-07-24

    High-energy cosmic rays with energies exceeding $10^{17}$ eV are frequently observed by measurements of the fluorescence light induced by air showers. A major contribution to the systematic uncertainties of the absolute energy scale of such experiments is the insufficient knowledge of the fluorescence light yield of electrons in air. The aim of the 5th Fluorescence Workshop was to bring together experimental and theoretical expertise to discuss the latest progress on the investigations of the fluorescence light yield. The results of the workshop will be reviewed as well as the present status of knowledge in this field. Emphasis is given to the fluorescence light yield important for air shower observations and its dependence on atmospheric parameters, like pressure, temperature, and humidity. The effects of the latest results on the light observed from air showers will be discussed.

  14. Methods of Determination of the Energy and Mass of Primary Cosmic Ray Particles at Extensive Air Shower Energies

    E-Print Network [OSTI]

    Karl-Heinz Kampert

    2001-01-29

    Measurements of cosmic ray particles at energies above E = 5 x 10^{14} eV are performed by large area ground based air shower experiments. Only they provide the collection power required for obtaining sufficient statistics at the low flux levels involved. In this review we briefly outline the physics and astrophysics interests of such measurements and discuss in more detail various experimental techniques applied for reconstructing the energy and mass of the primary particles. These include surface arrays of particle detectors as well as observations of Cherenkov- and of fluorescence light. A large variety of air shower observables is then reconstructed from such data and used to infer the properties of the primary particles via comparisons to air shower simulations. Advantages, limitations, and systematic uncertainties of different approaches will be critically discussed.

  15. Reconstruction of the energy and depth of maximum of cosmic-ray air-showers from LOPES radio measurements

    E-Print Network [OSTI]

    W. D. Apel; J. C. Arteaga-Velazquez; L. Bähren; K. Bekk; M. Bertaina; P. L. Biermann; J. Blümer; H. Bozdog; I. M. Brancus; E. Cantoni; A. Chiavassa; K. Daumiller; V. de Souza; F. Di Pierro; P. Doll; R. Engel; H. Falcke; B. Fuchs; D. Fuhrmann; H. Gemmeke; C. Grupen; A. Haungs; D. Heck; J. R. Hörandel; A. Horneffer; D. Huber; T. Huege; P. G. Isar; K. -H. Kampert; D. Kang; O. Krömer; J. Kuijpers; K. Link; P. ?uczak; M. Ludwig; H. J. Mathes; M. Melissas; C. Morello; J. Oehlschläger; N. Palmieri; T. Pierog; J. Rautenberg; H. Rebel; M. Roth; C. Rühle; A. Saftoiu; H. Schieler; A. Schmidt; F. G. Schröder; O. Sima; G. Toma; G. C. Trinchero; A. Weindl; J. Wochele; J. Zabierowski; J. A. Zensus

    2014-08-11

    LOPES is a digital radio interferometer located at Karlsruhe Institute of Technology (KIT), Germany, which measures radio emission from extensive air showers at MHz frequencies in coincidence with KASCADE-Grande. In this article, we explore a method (slope method) which leverages the slope of the measured radio lateral distribution to reconstruct crucial attributes of primary cosmic rays. First, we present an investigation of the method on the basis of pure simulations. Second, we directly apply the slope method to LOPES measurements. Applying the slope method to simulations, we obtain uncertainties on the reconstruction of energy and depth of shower maximum Xmax of 13% and 50 g/cm^2, respectively. Applying it to LOPES measurements, we are able to reconstruct energy and Xmax of individual events with upper limits on the precision of 20-25% for the primary energy and 95 g/cm^2 for Xmax, despite strong human-made noise at the LOPES site.

  16. On the possibility of cosmic ray-induced ionizing radiation-powered life in subsurface environments in the Universe

    E-Print Network [OSTI]

    Atri, Dimitra

    2015-01-01

    Photosynthesis is a highly efficient mechanism developed by terrestrial life to utilize the energy from photons of solar origin for biological use. Subsurface regions are isolated from the photosphere, and consequently are incapable of utilizing this energy. This opens up the opportunity for life to cultivate alternative mechanisms in order to take advantage of other available energy sources. Studies have shown that in subsurface environments, life can use energy generated from geochemical and geothermal processes to sustain a minimal metabolism. Another mechanism is radiolysis, in which particles emitted by radioactive substances are indirectly utilized for metabolism. One such example is the bacterium fueled by radiation, found 2 miles deep in a South African mine, which consumes hydrogen formed from particles emitted by radioactive U, Th and K present in rock. An additional source of radiation in the subsurface environments is secondary particles, such as muons generated by Galactic Cosmic Rays (GCRs). It ...

  17. Reconstructing the Cosmic Expansion History up to Redshift z=6.29 with the Calibrated Gamma-Ray Bursts

    E-Print Network [OSTI]

    Hao Wei; Shuang Nan Zhang

    2009-08-31

    Recently, Gamma-Ray Bursts (GRBs) were proposed to be a complementary cosmological probe to type Ia supernovae (SNIa). GRBs have been advocated to be standard candles since several empirical GRB luminosity relations were proposed as distance indicators. However, there is a so-called circularity problem in the direct use of GRBs. Recently, a new idea to calibrate GRBs in a completely cosmology independent manner has been proposed, and the circularity problem can be solved. In the present work, following the method proposed by Liang {\\it et al.}, we calibrate 70 GRBs with the Amati relation using 307 SNIa. Then, following the method proposed by Shafieloo {\\it et al.}, we smoothly reconstruct the cosmic expansion history up to redshift $z=6.29$ with the calibrated GRBs. We find some new features in the reconstructed results.

  18. Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abreu, P

    2011-06-17

    The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies E > Eth = 5.5 x 1019 eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at E > Eth are heavy nuclei with charge Z, the proton component of the sources should lead to excesses in the same regions at energies E/Z. We here report the lack of anisotropies in these directions at energies above Eth/Z (for illustrativemore »values of Z = 6,13,26). If the anisotropies above Eth are due to nuclei with charge Z, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies.« less

  19. Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abreu, P [Lisbon, IST; Aglietta, M [IFSI, Turin; Ahn, E J [Fermilab; Albuquerque, I F.M. [Sao Paulo U.; Allard, D [APC, Paris; Allekotte, I [Centro Atomico Bariloche; Allen, J [New York U.; Allison, P [Ohio State U.; Alvarez Castillo, J [Mexico U., ICN; Alvarez-Muniz, J [Santiago de Compostela U.; Ambrosio, M [Napoli Seconda U.; INFN, Naples; Nijmegen U., IMAPP

    2011-06-17

    The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies E > Eth = 5.5 x 1019 eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at E > Eth are heavy nuclei with charge Z, the proton component of the sources should lead to excesses in the same regions at energies E/Z. We here report the lack of anisotropies in these directions at energies above Eth/Z (for illustrative values of Z = 6,13,26). If the anisotropies above Eth are due to nuclei with charge Z, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies.

  20. Irradiated shocks in the W28 A2 massive star-forming region: a site for cosmic rays acceleration?

    E-Print Network [OSTI]

    Gusdorf, A; Gerin, M; Guesten, R

    2015-01-01

    The formation of massive stars play a crucial role in galaxies from numerous points of view. The protostar generates a strong ultraviolet radiation field that ionizes its surroundings, and it drives powerful shock waves in the neighbouring medium in the form of jets and bipolar outflows, whose structure can be partially organized by local, strong magnetic field. Such an ejection activity locally modifies the interstellar chemistry, contributing to the cycle of matter. It also significantly participates to the energetic balance of galaxies. In the latter stages of massive star formation, the protostar is surrounded by an ultra-compact HII region, and irradiates its bipolar outflows, where an intrinsically strong magnetic field structure is associated to the generally high densities. In the HII region, or in the bipolar outflows, the question of in situ cosmic rays acceleration can then be raised by the simultaneous presence of strong magnetic fields, significant ionization of the matter, and mechanical energy ...

  1. An implicit scheme for solving the anisotropic diffusion of heat and cosmic rays in the RAMSES code

    E-Print Network [OSTI]

    Dubois, Yohan

    2015-01-01

    Astrophysical plasmas are subject to a tight connection between magnetic fields and the diffusion of particles, which leads to an anisotropic transport of energy. Under the fluid assumption, this effect can be reduced to an advection-diffusion equation augmenting the equations of magnetohydrodynamics. We introduce a new method for solving the anisotropic diffusion equation using an implicit finite-volume method with adaptive mesh refinement and adaptive time-stepping in the RAMSES code. We apply this numerical solver to the diffusion of cosmic ray energy, and diffusion of heat carried by electrons, which couple to the ion temperature. We test this new implementation against several numerical experiments and apply it to a simple supernova explosion with a uniform magnetic field.

  2. Measurement of Cosmic-ray Muons and Muon-induced Neutrons in the Aberdeen Tunnel Underground Laboratory

    E-Print Network [OSTI]

    Blyth, S C; Chen, X C; Chu, M C; Cui, K X; Hahn, R L; Ho, T H; Hsiung, Y B; Hu, B Z; Kwan, K K; Kwok, M W; Kwok, T; Lau, Y P; Leung, J K C; Leung, K Y; Lin, G L; Lin, Y C; Luk, K B; Luk, W H; Ngai, H Y; Ngan, S Y; Pun, C S J; Shih, K; Tam, Y H; Tsang, R H M; Wang, C H; Wong, C M; Wong, H L; Wong, K K; Yeh, M; Zhang, B J

    2015-01-01

    We measured the muon flux and the production rate of muon-induced neutrons at a depth of 611 meters water equivalent. Our apparatus comprises of three layers of crossed plastic scintillator hodoscopes for tracking the incident cosmic-ray muons, and 760 L of gadolinium-doped liquid scintillator for both neutron production and detection targets. The vertical muon intensity was measured to be $I_{\\mu}$ = (5.7 $\\pm$ 0.6) $\\times$ 10$^{-6}$ cm$^{-2}$ s$^{-1}$ sr$^{-1}$. The muon-induced neutron yield in the liquid scintillator was determined to be $Y_{n}$ = (1.19 $\\pm$ 0.08(stat.) $\\pm$ 0.21(syst.)) $\\times$ 10$^{-4}$ neutrons / ($\\mu$ g cm$^{-2}$). A fitting to recently measured neutron yields at different depths gave a muon energy dependence of $\\left\\langle E_{\\mu} \\right\\rangle^{0.76 \\pm 0.03}$ for scintillator targets.

  3. Precise mapping of the magnetic field in the CMS barrel yoke using cosmic rays

    SciTech Connect (OSTI)

    Chatrchyan, S.; et al.,

    2010-03-01

    The CMS detector is designed around a large 4 T superconducting solenoid, enclosed in a 12000-tonne steel return yoke. A detailed map of the magnetic field is required for the accurate simulation and reconstruction of physics events in the CMS detector, not only in the inner tracking region inside the solenoid but also in the large and complex structure of the steel yoke, which is instrumented with muon chambers. Using a large sample of cosmic muon events collected by CMS in 2008, the field in the steel of the barrel yoke has been determined with a precision of 3 to 8% depending on the location.

  4. Solar panels as air Cherenkov detectors for extremely high energy cosmic rays

    E-Print Network [OSTI]

    Cecchini, S; Esposti, L D; Giacomelli, G; Guerra, M; Lax, I; Mandrioli, G; Parretta, A; Sarno, A; Schioppo, R; Sorel, M; Spurio, M

    2000-01-01

    Increasing interest towards the observation of the highest energy cosmic rayshas motivated the development of new detection techniques. The properties ofthe Cherenkov photon pulse emitted in the atmosphere by these very rareparticles indicate low-cost semiconductor detectors as good candidates fortheir optical read-out. The aim of this paper is to evaluate the viability of solar panels for thispurpose. The experimental framework resulting from measurements performed withsuitably-designed solar cells and large conventional photovoltaic areas ispresented. A discussion on the obtained and achievable sensitivities follows.

  5. Evidences of high energy protons with energies beyond 0.4 GeV in the solar particle spectrum as responsible for the cosmic rays solar diurnal anisotropy

    E-Print Network [OSTI]

    C. E. Navia; C. R. A. Augusto; M. B. Robba; K. H. Tsui

    2007-06-26

    Analysis on the daily variations of cosmic ray muons with $E_{\\mu}\\geq 0.2 GeV$ based on the data of two directional muon telescopes at sea level and with a rigidity of response to cosmic proton spectrum above 0.4 GV is presented. The analysis covers two months of observations and in 60% of days, abrupt transitions between a low to a high muon intensity and vice-verse is observed, the period of high muon intensity is from $\\sim 8.0h$ up to $\\sim 19.0h$ (local time) and coincides with the period when the interplanetary magnetic field (IMF) lines overtake the Earth. This behavior strongly suggest that the high muon intensity is due to a contribution of solar protons (ions) on the muon intensity produced by the galactic cosmic rays, responsible for the low muon intensity. This implies that the solar particle spectrum extends to energies beyond 1 GeV. We show that this picture can explain the solar daily variation origin, and it is a most accurate scenario than the assumption of corotating galactic cosmic ray with the IMF lines, specially in the high rigidity region. Obtained results are consistent with the data reported in others papers. Some aspects on the sensitivity of our muon telescopes are also presented.

  6. arXiv:astro-ph/9709211v122Sep1997 Modelling cosmic rays

    E-Print Network [OSTI]

    Moskalenko, Igor V.

    of diffuse Galac- tic gamma rays for comparison with data from the cgro instruments egret, comptel, and osse. The basic spatial propagation mechanisms are (momentum- dependent) diffusion, convection, while in momentum is able to take advantage of this since it must be consistent with all types of observation. We emphasize

  7. New cosmic rays experiments in the underground laboratory of IFIN-HH from Slanic Prahova, Romania

    SciTech Connect (OSTI)

    Mitrica, Bogdan; Stanca, Denis; Brancus, Iliana; Margineanu, Romul; Blebea-Apostu, Ana-Maria; Gomoiu, Claudia; Saftoiu, Alexandra; Toma, Gabriel; Gherghel-Lascu, Alexandru; Niculescu-Oglinzanu, Mihai; Rebel, Heinigerd; Haungs, Andreas; Sima, Octavian

    2015-02-24

    Since 2006 a modern laboratory has been developed by IFIN-HH in the underground of Slanic Prahova salt ore. This work presents a short review of previous scientific activities performed in the underground laboratory, in parallel with some plans for the future. A mobile detector for cosmic muon flux measurements has been set up at IFIN-HH, Romania. The device is used to measure the muon flux on different locations at the surface and underground and it consists of two detection layers, each one including four large scintillator plates. A new rotatable detector for measurements of the directional variation of the muon flux has been designed and it is presently under preliminary tests. Built from four layers of sensitive material and using for collecting the signals and directing them to the micro PMTs a new technique, through optical fibers instead wave length shifters, it allows an easy discrimination of the moun flux on the arrival directions of muons. Combining the possibility to rotate and the directionality properties, the underground muon detector is acting like a muon tomography device, being able to scan, using cosmic muons, the rock material above the detector. In parallel new detection system based on SiPM will be also installed in the following weeks. It should be composed by four layers, each layer consisting in 4 scintillator plates what we consider in the following as a module of detection. For this purpose, first two scintillator layers, with the optical fibers positioned on perpendicular directions are put in coincidence with other two layers, 1 m distance from the first two, with similar optical fiber arrangement, thus allowing reconstructing muon trajectory. It is intended also to design and construct an experimental device for the investigation of such radio antennas and the behavior of the signal in rock salt at the Slanic salt mine in Romania. Another method to detect high energy neutrinos is based on the detection of secondary particles resulting from the interaction with the salt massive. We intent to design and construct a 3D array in the underground of Slanic Prahova salt ore.

  8. A correlation between hard gamma-ray sources and cosmic voids along the line of sight

    SciTech Connect (OSTI)

    Furniss, A.; Sutter, P. M.; Primack, J. R.; Dominguez, A.

    2014-11-25

    We estimate the galaxy density along lines of sight to hard extragalactic gamma-ray sources by correlating source positions on the sky with a void catalog based on the Sloan Digital Sky Survey (SDSS). Extragalactic gamma-ray sources that are detected at very high energy (VHE; E > 100 GeV) or have been highlighted as VHE-emitting candidates in the Fermi Large Area Telescope hard source catalog (together referred to as “VHE-like” sources) are distributed along underdense lines of sight at the 2.4#27; level. There is also a less suggestive correlation for the Fermi hard source population (1.7#27;). A correlation between 10-500 GeV flux and underdense fraction along the line of sight for VHE-like and Fermi hard sources is found at 2.4#27; and 2.6#27;, calculated from the Pearson correlation coefficients of r = 0.57 and 0.47, respectively. The preference for underdense sight lines is not displayed by gamma-ray emitting galaxies within the second Fermi catalog, containing sources detected above 100 MeV, or the SDSS DR7 quasar catalog. We investigate whether this marginal correlation might be a result of lower extragalactic background light (EBL) photon density within the underdense regions and find that, even in the most extreme case of a entirely underdense sight line, the EBL photon density is only 2% less than the nominal EBL density. Translating this into gamma-ray attenuation along the line of sight for a highly attenuated source with opacity #28;(E, z) #24; 5, we estimate that the attentuation of gamma-rays decreases no more than 10%. This decrease, although non-neglible, is unable to account for the apparent hard source correlation with underdense lines of sight.

  9. A correlation between hard gamma-ray sources and cosmic voids along the line of sight

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Furniss, A.; Sutter, P. M.; Primack, J. R.; Dominguez, A.

    2014-11-25

    We estimate the galaxy density along lines of sight to hard extragalactic gamma-ray sources by correlating source positions on the sky with a void catalog based on the Sloan Digital Sky Survey (SDSS). Extragalactic gamma-ray sources that are detected at very high energy (VHE; E > 100 GeV) or have been highlighted as VHE-emitting candidates in the Fermi Large Area Telescope hard source catalog (together referred to as “VHE-like” sources) are distributed along underdense lines of sight at the 2.4? level. There is a less suggestive correlation for the Fermi hard source population (1.7?). A correlation between 10-500 GeV fluxmore »and underdense fraction along the line of sight for VHE-like and Fermi hard sources is found at 2.4? and 2.6?, calculated from the Pearson correlation coefficients of r = 0.57 and 0.47, respectively. The preference for underdense sight lines is not displayed by gamma-ray emitting galaxies within the second Fermi catalog, containing sources detected above 100 MeV, or the SDSS DR7 quasar catalog. We investigate whether this marginal correlation might be a result of lower extragalactic background light (EBL) photon density within the underdense regions and find that, even in the most extreme case of a entirely underdense sight line, the EBL photon density is only 2% less than the nominal EBL density. Translating this into gamma-ray attenuation along the line of sight for a highly attenuated source with opacity ?(E, z) ~ 5, we estimate that the attentuation of gamma-rays decreases no more than 10%. This decrease, although non-neglible, is unable to account for the apparent hard source correlation with underdense lines of sight.« less

  10. Response of Atmospheric Biomarkers to NOx-induced Photochemistry Generated by Stellar Cosmic Rays for Earth-like Planets in the Habitable Zone of M-Dwarf Stars

    E-Print Network [OSTI]

    Grenfell, John Lee; von Paris, Philip; Patzer, Beate; Lammer, Helmut; Stracke, Barbara; Gebauer, Stefanie; Schreier, Franz; Rauer, Heike

    2015-01-01

    Understanding whether M-dwarf stars may host habitable planets with Earth-like atmospheres and biospheres is a major goal in exoplanet research. If such planets exist, the question remains as to whether they could be identified via spectral signatures of biomarkers. Such planets may be exposed to extreme intensities of cosmic rays that could perturb their atmospheric photochemistry. Here, we consider stellar activity of M-dwarfs ranging from quiet up to strong flaring conditions and investigate one particular effect upon biomarkers, namely, the ability of secondary electrons caused by stellar cosmic rays to break up atmospheric molecular nitrogen (N2), which leads to production of nitrogen oxides in the planetary atmosphere, hence affecting biomarkers such as ozone. We apply a stationary model, that is, without a time-dependence, hence we are calculating the limiting case where the atmospheric chemistry response time of the biomarkers is assumed to be slow and remains constant compared with rapid forcing by t...

  11. Measurement of the Cosmic Ray Energy Spectrum and Composition from 10^{17} to 10^{18.3} eV Using a Hybrid Fluorescence Technique

    E-Print Network [OSTI]

    T. Abu-Zayyad; K. Belov; D. J. Bird; J. Boyer; Z. Cao; M. Catanese; G. F. Chen; R. W. Clay; C. E. Covault; H. Y. Dai; B. R. Dawson; J. W. Elbert; B. E. Fick; L. F. Fortson; J. W. Fowler; K. G. Gibbs; M. A. K. Glasmacher; K. D. Green; Y. Ho; A. Huang; C. C. Jui; M. J. Kidd; D. B. Kieda; B. C. Knapp; S. Ko; C. G. Larsen; W. Lee; E. C. Loh; E. J. Mannel; J. Matthews; J. N. Matthews; B. J. Newport; D. F. Nitz; R. A. Ong; K. M. Simpson; J. D. Smith; D. Sinclair; P. Sokolsky; P. Sommers; C. Song; J. K. K. Tang; S. B. Thomas; J. .van der Velde; L. R. Wiencke; C. R. Wilkinson; S. Yoshida; X. Z. Zhang

    2000-10-31

    We study the spectrum and average mass composition of cosmic rays with primary energies between 10^{17} eV and 10^{18} eV using a hybrid detector consisting of the High Resolution Fly's Eye (HiRes) prototype and the MIA muon array. Measurements have been made of the change in the depth of shower maximum as a function of energy. A complete Monte Carlo simulation of the detector response and comparisons with shower simulations leads to the conclusion that the cosmic ray intensity is changing f rom a heavier to a lighter composition in this energy range. The spectrum is consistent with earlier Fly's Eye measurements and supports the previously found steepening near 4 \\times 10^{17} eV .

  12. Relative Damaging Ability Of Galactic Cosmic Rays Determined Using Monte Carlo Simulations Of Track Structure 

    E-Print Network [OSTI]

    Cox, Bradley

    2012-10-19

    ..................................................................... 15 4 Delta rays are produced when the primary ion passes and receive kinetic energy based on the angle and impact parameter ........................... 19 5 Electron penetration distance in water vs. kinetic energy... of 100 keV um-1 in a 1 µm thick water slab .................... 43 10 Spectrum of energy deposition events in a 1 µm thick water slab for ions having equal velocities of 600 MeV n-1 ........................................ 44 11 Si-28 ion...

  13. Search for Point Sources of Ultra-High Energy Cosmic Rays Above 40 EeV Using a Maximum Likelihood Ratio Test

    E-Print Network [OSTI]

    The High Resolution Fly's Eye Collaboration; G. R. Farrar

    2004-12-23

    We present the results of a search for cosmic ray point sources at energies above 40 EeV in the combined data sets recorded by the AGASA and HiRes stereo experiments. The analysis is based on a maximum likelihood ratio test using the probability density function for each event rather than requiring an a priori choice of a fixed angular bin size. No statistically significant clustering of events consistent with a point source is found.

  14. Measurement of the Shadowing of High-Energy Cosmic Rays by the Moon: A Search for TeV-Energy Antiprotons

    E-Print Network [OSTI]

    L3 Collaboration; P. Achard

    2005-03-22

    The shadowing of high-energy cosmic rays by the Moon has been observed with a significance of 9.4 standard deviations with the L3+C muon spectrometer at CERN. A significant effect of the Earth magnetic field is observed. Since no event deficit on the east side of the Moon has been observed, an upper limit at 90% confidence level on the antiproton to proton ratio of 0.11 is obtained for primary energies around 1 TeV.

  15. The effect of the geomagnetic field on cosmic ray energy estimates and large scale anisotropy searches on data from the Pierre Auger Observatory

    SciTech Connect (OSTI)

    Abreu, P.; Aglietta, M.; Ahn, E.J.; Albuquerque, I.F.M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Alvarez Castillo, J.; Alvarez-Muniz, J.; Ambrosio, M.; ,

    2011-11-01

    We present a comprehensive study of the influence of the geomagnetic field on the energy estimation of extensive air showers with a zenith angle smaller than 60{sup o}, detected at the Pierre Auger Observatory. The geomagnetic field induces an azimuthal modulation of the estimated energy of cosmic rays up to the {approx} 2% level at large zenith angles. We present a method to account for this modulation of the reconstructed energy. We analyse the effect of the modulation on large scale anisotropy searches in the arrival direction distributions of cosmic rays. At a given energy, the geomagnetic effect is shown to induce a pseudo-dipolar pattern at the percent level in the declination distribution that needs to be accounted for. In this work, we have identified and quantified a systematic uncertainty affecting the energy determination of cosmic rays detected by the surface detector array of the Pierre Auger Observatory. This systematic uncertainty, induced by the influence of the geomagnetic field on the shower development, has a strength which depends on both the zenith and the azimuthal angles. Consequently, we have shown that it induces distortions of the estimated cosmic ray event rate at a given energy at the percent level in both the azimuthal and the declination distributions, the latter of which mimics an almost dipolar pattern. We have also shown that the induced distortions are already at the level of the statistical uncertainties for a number of events N {approx_equal} 32 000 (we note that the full Auger surface detector array collects about 6500 events per year with energies above 3 EeV). Accounting for these effects is thus essential with regard to the correct interpretation of large scale anisotropy measurements taking explicitly profit from the declination distribution.

  16. The cosmic ray proton plus helium energy spectrum measured by the ARGO-YBJ experiment in the energy range 3-300 TeV

    E-Print Network [OSTI]

    :,; Bernardini, P; Bi, X J; Cao, Z; Catalanotti, S; Chen, S Z; Chen, T L; Cui, S W; Dai, B Z; D'Amone, A; Danzengluobu,; De Mitri, I; Piazzoli, B D'Ettorre; Di Girolamo, T; Di Sciascio, G; Feng, C F; Feng, Zhaoyang; Feng, Zhenyong; Gou, Q B; Guo, Y Q; He, H H; Hu, Haibing; Hu, Hongbo; Iacovacci, M; Iuppa, R; Jia, H Y; Labaciren,; Li, H J; Liu, C; Liu, J; Liu, M Y; Lu, H; Ma, L L; Ma, X H; Mancarella, G; Mari, S M; Marsella, G; Mastroianni, S; Montini, P; Ning, C C; Perrone, L; Pistilli, P; Salvini, P; Santonico, R; Settanta, G; Shen, P R; Sheng, X D; Shi, F; Surdo, A; Tan, Y H; Vallania, P; Vernetto, S; Vigorito, C; Wang, H; Wu, C Y; Wu, H R; Xue, L; Yang, Q Y; Yang, X C; Yao, Z G; Yuan, A F; Zha, M; Zhang, H M; Zhang, L; Zhang, X Y; Zhang, Y; Zhao, J; Zhaxiciren,; Zhaxisangzhu,; Zhou, X X; Zhu, F R; Zhu, Q Q

    2015-01-01

    The ARGO-YBJ experiment is a full-coverage air shower detector located at the Yangbajing Cosmic Ray Observatory (Tibet, People's Republic of China, 4300 m a.s.l.). The high altitude, combined with the full-coverage technique, allows the detection of extensive air showers in a wide energy range and offer the possibility of measuring the cosmic ray proton plus helium spectrum down to the TeV region, where direct balloon/space-borne measurements are available. The detector has been in stable data taking in its full configuration from November 2007 to February 2013. In this paper the measurement of the cosmic ray proton plus helium energy spectrum is presented in the region 3-300 TeV by analyzing the full collected data sample. The resulting spectral index is $\\gamma = -2.64 \\pm 0.01$. These results demonstrate the possibility of performing an accurate measurement of the spectrum of light elements with a ground based air shower detector.

  17. The cosmic ray proton plus helium energy spectrum measured by the ARGO-YBJ experiment in the energy range 3-300 TeV

    E-Print Network [OSTI]

    The ARGO-YBJ Collaboration; :; B. Bartoli; P. Bernardini; X. J. Bi; Z. Cao; S. Catalanotti; S. Z. Chen; T. L. Chen; S. W. Cui; B. Z. Dai; A. D'Amone; Danzengluobu; I. De Mitri; B. D'Ettorre Piazzoli; T. Di Girolamo; G. Di Sciascio; C. F. Feng; Zhaoyang Feng; Zhenyong Feng; Q. B. Gou; Y. Q. Guo; H. H. He; Haibing Hu; Hongbo Hu; M. Iacovacci; R. Iuppa; H. Y. Jia; Labaciren; H. J. Li; C. Liu; J. Liu; M. Y. Liu; H. Lu; L. L. Ma; X. H. Ma; G. Mancarella; S. M. Mari; G. Marsella; S. Mastroianni; P. Montini; C. C. Ning; L. Perrone; P. Pistilli; P. Salvini; R. Santonico; G. Settanta; P. R. Shen; X. D. Sheng; F. Shi; A. Surdo; Y. H. Tan; P. Vallania; S. Vernetto; C. Vigorito; H. Wang; C. Y. Wu; H. R. Wu; L. Xue; Q. Y. Yang; X. C. Yang; Z. G. Yao; A. F. Yuan; M. Zha; H. M. Zhang; L. Zhang; X. Y. Zhang; Y. Zhang; J. Zhao; Zhaxiciren; Zhaxisangzhu; X. X. Zhou; F. R. Zhu; Q. Q. Zhu

    2015-03-24

    The ARGO-YBJ experiment is a full-coverage air shower detector located at the Yangbajing Cosmic Ray Observatory (Tibet, People's Republic of China, 4300 m a.s.l.). The high altitude, combined with the full-coverage technique, allows the detection of extensive air showers in a wide energy range and offer the possibility of measuring the cosmic ray proton plus helium spectrum down to the TeV region, where direct balloon/space-borne measurements are available. The detector has been in stable data taking in its full configuration from November 2007 to February 2013. In this paper the measurement of the cosmic ray proton plus helium energy spectrum is presented in the region 3-300 TeV by analyzing the full collected data sample. The resulting spectral index is $\\gamma = -2.64 \\pm 0.01$. These results demonstrate the possibility of performing an accurate measurement of the spectrum of light elements with a ground based air shower detector.

  18. The Lateral Trigger Probability function for the Ultra-High Energy Cosmic Ray Showers detected by the Pierre Auger Observatory

    E-Print Network [OSTI]

    The Pierre Auger Collaboration; P. Abreu; M. Aglietta; E. J. Ahn; I. F. M. Albuquerque; D. Allard; I. Allekotte; J. Allen; P. Allison; J. Alvarez Castillo; J. Alvarez-Muńiz; M. Ambrosio; A. Aminaei; L. Anchordoqui; S. Andringa; T. Anti?i?; A. Anzalone; C. Aramo; E. Arganda; F. Arqueros; H. Asorey; P. Assis; J. Aublin; M. Ave; M. Avenier; G. Avila; T. Bäcker; M. Balzer; K. B. Barber; A. F. Barbosa; R. Bardenet; S. L. C. Barroso; B. Baughman; J. Bäuml; J. J. Beatty; B. R. Becker; K. H. Becker; A. Bellétoile; J. A. Bellido; S. BenZvi; C. Berat; X. Bertou; P. L. Biermann; P. Billoir; F. Blanco; M. Blanco; C. Bleve; H. Blümer; M. Bohá?ová; D. Boncioli; C. Bonifazi; R. Bonino; N. Borodai; J. Brack; P. Brogueira; W. C. Brown; R. Bruijn; P. Buchholz; A. Bueno; R. E. Burton; K. S. Caballero-Mora; L. Caramete; R. Caruso; A. Castellina; O. Catalano; G. Cataldi; L. Cazon; R. Cester; J. Chauvin; S. H. Cheng; A. Chiavassa; J. A. Chinellato; A. Chou; J. Chudoba; R. W. Clay; M. R. Coluccia; R. Conceiçăo; F. Contreras; H. Cook; M. J. Cooper; J. Coppens; A. Cordier; S. Coutu; C. E. Covault; A. Creusot; A. Criss; J. Cronin; A. Curutiu; S. Dagoret-Campagne; R. Dallier; S. Dasso; K. Daumiller; B. R. Dawson; R. M. de Almeida; M. De Domenico; C. De Donato; S. J. de Jong; G. De La Vega; W. J. M. de Mello Junior; J. R. T. de Mello Neto; I. De Mitri; V. de Souza; K. D. de Vries; G. Decerprit; L. del Peral; M. del Río; O. Deligny; H. Dembinski; N. Dhital; C. Di Giulio; J. C. Diaz; M. L. Díaz Castro; P. N. Diep; C. Dobrigkeit; W. Docters; J. C. D'Olivo; P. N. Dong; A. Dorofeev; J. C. dos Anjos; M. T. Dova; D. D'Urso; I. Dutan; J. Ebr; R. Engel; M. Erdmann; C. O. Escobar; J. Espadanal; A. Etchegoyen; P. Facal San Luis; I. Fajardo Tapia; H. Falcke; G. Farrar; A. C. Fauth; N. Fazzini; A. P. Ferguson; A. Ferrero; B. Fick; A. Filevich; A. Filip?i?; S. Fliescher; C. E. Fracchiolla; E. D. Fraenkel; U. Fröhlich; B. Fuchs; R. Gaior; R. F. Gamarra; S. Gambetta; B. García; D. García Gámez; D. Garcia-Pinto; A. Gascon; H. Gemmeke; K. Gesterling; P. L. Ghia; U. Giaccari; M. Giller; H. Glass; M. S. Gold; G. Golup; F. Gomez Albarracin; M. Gómez Berisso; P. Gonçalves; D. Gonzalez; J. G. Gonzalez; B. Gookin; D. Góra; A. Gorgi; P. Gouffon; S. R. Gozzini; E. Grashorn; S. Grebe; N. Griffith; M. Grigat; A. F. Grillo; Y. Guardincerri; F. Guarino; G. P. Guedes; A. Guzman; J. D. Hague; P. Hansen; D. Harari; S. Harmsma; J. L. Harton; A. Haungs; T. Hebbeker; D. Heck; A. E. Herve; C. Hojvat; N. Hollon; V. C. Holmes; P. Homola; J. R. Hörandel; A. Horneffer; M. Hrabovský; T. Huege; A. Insolia; F. Ionita; A. Italiano; C. Jarne; S. Jiraskova; M. Josebachuili; K. Kadija; K. H. Kampert; P. Karhan; P. Kasper; B. Kégl; B. Keilhauer; A. Keivani; J. L. Kelley; E. Kemp; R. M. Kieckhafer; H. O. Klages; M. Kleifges; J. Kleinfeller; J. Knapp; D. -H. Koang; K. Kotera; N. Krohm; O. Krömer; D. Kruppke-Hansen; F. Kuehn; D. Kuempel; J. K. Kulbartz; N. Kunka; G. La Rosa; C. Lachaud; P. Lautridou; M. S. A. B. Leăo; D. Lebrun; P. Lebrun; M. A. Leigui de Oliveira; A. Lemiere; A. Letessier-Selvon; I. Lhenry-Yvon; K. Link; R. López; A. Lopez Agüera; K. Louedec; J. Lozano Bahilo; L. Lu; A. Lucero; M. Ludwig; H. Lyberis; M. C. Maccarone; C. Macolino; S. Maldera; D. Mandat; P. Mantsch; A. G. Mariazzi; J. Marin; V. Marin; I. C. Maris; H. R. Marquez Falcon; G. Marsella; D. Martello; L. Martin; H. Martinez; O. Martínez Bravo; H. J. Mathes; J. Matthews; J. A. J. Matthews; G. Matthiae; D. Maurizio; P. O. Mazur; G. Medina-Tanco; M. Melissas; D. Melo; E. Menichetti; A. Menshikov; P. Mertsch; C. Meurer; S. Mi?anovi?; M. I. Micheletti; W. Miller; L. Miramonti; L. Molina-Bueno; S. Mollerach; M. Monasor; D. Monnier Ragaigne; F. Montanet; B. Morales; C. Morello; E. Moreno; J. C. Moreno; C. Morris; M. Mostafá; C. A. Moura; S. Mueller; M. A. Muller; G. Müller; M. Münchmeyer; R. Mussa; G. Navarra ‡; J. L. Navarro; S. Navas; P. Necesal; L. Nellen; A. Nelles; J. Neuser; P. T. Nhung; L. Niemietz; N. Nierstenhoefer; D. Nitz; D. Nosek; L. Nožka; M. Nyklicek; J. Oehlschläger; A. Olinto; P. Oliva; V. M. Olmos-Gilbaja; M. Ortiz; N. Pacheco; D. Pakk Selmi-Dei; M. Palatka; J. Pallotta; N. Palmieri; G. Parente; E. Parizot; A. Parra; R. D. Parsons; S. Pastor; T. Paul; M. Pech; J. P?kala; R. Pelayo; I. M. Pepe; L. Perrone; R. Pesce; E. Petermann; S. Petrera; P. Petrinca; A. Petrolini; Y. Petrov; J. Petrovic; C. Pfendner; N. Phan; R. Piegaia; T. Pierog; P. Pieroni; M. Pimenta; V. Pirronello; M. Platino; V. H. Ponce; M. Pontz; P. Privitera; M. Prouza; E. J. Quel; S. Querchfeld; J. Rautenberg; O. Ravel; D. Ravignani; B. Revenu; J. Ridky; S. Riggi; M. Risse; P. Ristori; H. Rivera; V. Rizi; J. Roberts; C. Robledo; W. Rodrigues de Carvalho; G. Rodriguez; J. Rodriguez Martino; J. Rodriguez Rojo

    2011-11-28

    In this paper we introduce the concept of Lateral Trigger Probability (LTP) function, i.e., the probability for an extensive air shower (EAS) to trigger an individual detector of a ground based array as a function of distance to the shower axis, taking into account energy, mass and direction of the primary cosmic ray. We apply this concept to the surface array of the Pierre Auger Observatory consisting of a 1.5 km spaced grid of about 1600 water Cherenkov stations. Using Monte Carlo simulations of ultra-high energy showers the LTP functions are derived for energies in the range between 10^{17} and 10^{19} eV and zenith angles up to 65 degs. A parametrization combining a step function with an exponential is found to reproduce them very well in the considered range of energies and zenith angles. The LTP functions can also be obtained from data using events simultaneously observed by the fluorescence and the surface detector of the Pierre Auger Observatory (hybrid events). We validate the Monte-Carlo results showing how LTP functions from data are in good agreement with simulations.

  19. A Detailed Study of FDIRC Prototype with Waveform Digitizing Electronics in Cosmic Ray Telescope Using 3D Tracks

    SciTech Connect (OSTI)

    Nishimura, K.; Dey, B.; Aston, D.; Leith, D.W.G.S.; Ratcliff, B.; Roberts, D.; Ruckman, L.; Shtol, D.; Varner, G.S.; Va'vra, J.; Vavra, Jerry; ,

    2012-07-30

    We present a detailed study of a novel Cherenkov imaging detector called the Focusing DIRC (FDIRC) with waveform digitizing electronics. In this test study, the FDIRC prototype has been instrumented with seven Hamamatsu H-8500 MaPMTs. Waveforms from {approx}450 pixels are digitized with waveform sampling electronics based on the BLAB2 ASIC, operating at a sampling speed of {approx}2.5 GSa/s. The FDIRC prototype was tested in a large cosmic ray telescope (CRT) providing 3D muon tracks with {approx}1.5 mrad angular resolution and muon energy of E{sub muon} > 1.6 GeV. In this study we provide a detailed analysis of the tails in the Cherenkov angle distribution as a function of various variables, compare experimental results with simulation, and identify the major contributions to the tails. We demonstrate that to see the full impact of these tails on the Cherenkov angle resolution, it is crucial to use 3D tracks, and have a full understanding of the role of ambiguities. These issues could not be fully explored in previous FDIRC studies where the beam was perpendicular to the quartz radiator bars. This work is relevant for the final FDIRC prototype of the PID detector at SuperB, which will be tested this year in the CRT setup.

  20. First measurement of radioactive isotope production through cosmic-ray muon spallation in Super-Kamiokande IV

    E-Print Network [OSTI]

    ,

    2015-01-01

    Cosmic-ray-muon spallation-induced radioactive isotopes with $\\beta$ decays are one of the major backgrounds for solar, reactor, and supernova relic neutrino experiments. Unlike in scintillator, production yields for cosmogenic backgrounds in water have not been exclusively measured before, yet they are becoming more and more important in next generation neutrino experiments designed to search for rare signals. We have analyzed the low-energy trigger data collected at Super-Kamiokande-IV in order to determine the production rates of $^{12}$B, $^{12}$N, $^{16}$N, $^{11}$Be, $^9$Li, $^8$He, $^9$C, $^8$Li, $^8$B and $^{15}$C. These rates were extracted from fits to time differences between parent muons and subsequent daughter $\\beta$'s by fixing the known isotope lifetimes. Since $^9$Li can fake an inverse-beta-decay reaction chain via a $\\beta + n$ cascade decay, producing an irreducible background with detected energy up to a dozen MeV, a dedicated study is needed for evaluating its impact on future measuremen...

  1. First measurement of radioactive isotope production through cosmic-ray muon spallation in Super-Kamiokande IV

    E-Print Network [OSTI]

    Super-Kamiokande Collaboration

    2015-09-28

    Cosmic-ray-muon spallation-induced radioactive isotopes with $\\beta$ decays are one of the major backgrounds for solar, reactor, and supernova relic neutrino experiments. Unlike in scintillator, production yields for cosmogenic backgrounds in water have not been exclusively measured before, yet they are becoming more and more important in next generation neutrino experiments designed to search for rare signals. We have analyzed the low-energy trigger data collected at Super-Kamiokande-IV in order to determine the production rates of $^{12}$B, $^{12}$N, $^{16}$N, $^{11}$Be, $^9$Li, $^8$He, $^9$C, $^8$Li, $^8$B and $^{15}$C. These rates were extracted from fits to time differences between parent muons and subsequent daughter $\\beta$'s by fixing the known isotope lifetimes. Since $^9$Li can fake an inverse-beta-decay reaction chain via a $\\beta + n$ cascade decay, producing an irreducible background with detected energy up to a dozen MeV, a dedicated study is needed for evaluating its impact on future measurements, the application of a neutron tagging technique using correlated triggers was found to improve this $^9$Li measurement. The measured yields were generally found to be comparable with theoretical calculations based on the simulation code FLUKA.

  2. Big-Bang Nucleosynthesis and Gamma-Ray Constraints on Cosmic Strings with a large Higgs condensate

    E-Print Network [OSTI]

    H. F. Santana Mota; Mark Hindmarsh

    2015-01-06

    We consider constraints on cosmic strings from their emission of Higgs particles, in the case that the strings have a Higgs condensate with amplitude of order the string mass scale, assuming that a fraction of the energy of condensate can be turned into radiation near cusps. The injection of energy by the decaying Higgs particles affects the light element abundances predicted by standard Big-Bang Nucleosynthesis (BBN), and also contributes to the Diffuse Gamma-Ray Background (DGRB) in the universe today. We examine the two main string scenarios (Nambu-Goto and field theory), and find that the primordial Helium abundance strongly constrains the string tension and the efficiency of the emission process in the NG scenario, while the strongest BBN constraint in the FT scenario comes from the Deuterium abundance. The Fermi-LAT measurement of the DGRB constrains the field theory scenario even more strongly than previously estimated from EGRET data, requiring that the product of the string tension {\\mu} and Newton's constant G is bounded by G{\\mu} < 2.7x10^{-11}{\\beta}_{ft}^{-2}, where {\\beta}_{ft}^2 is the fraction of the strings' energy going into Higgs particles.

  3. Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory

    SciTech Connect (OSTI)

    Abreu, P

    2011-06-17

    The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies E > Eth = 5.5 x 1019 eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at E > Eth are heavy nuclei with charge Z, the proton component of the sources should lead to excesses in the same regions at energies E/Z. We here report the lack of anisotropies in these directions at energies above Eth/Z (for illustrative values of Z = 6,13,26). If the anisotropies above Eth are due to nuclei with charge Z, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies.

  4. PRODUCTION OF {sup 9}Be THROUGH THE {alpha}-FUSION REACTION OF METAL-POOR COSMIC RAYS AND STELLAR FLARES

    SciTech Connect (OSTI)

    Kusakabe, Motohiko; Kawasaki, Masahiro E-mail: kawasaki@icrr.u-tokyo.ac.jp

    2013-04-10

    Spectroscopic observations of metal-poor stars have indicated possible {sup 6}Li abundances that are much larger than the primordial abundance predicted in the standard big bang nucleosynthesis model. Possible mechanisms of {sup 6}Li production in metal-poor stars include pregalactic and cosmological cosmic-ray (CR) nucleosynthesis and nucleosynthesis by flare-accelerated nuclides. We study {sup 9}Be production via two-step {alpha}-fusion reactions of CR or flare-accelerated {sup 3,4}He through {sup 6}He and {sup 6,7}Li, in pregalactic structure, intergalactic medium, and stellar surfaces. We solve transfer equations of CR or flare particles and calculate nuclear yields of {sup 6}He, {sup 6,7}Li, and {sup 9}Be taking account of probabilities of processing {sup 6}He and {sup 6,7}Li into {sup 9}Be via fusions with {alpha} particles. Yield ratios, i.e., {sup 9}Be/{sup 6}Li, are then calculated for the CR and flare nucleosynthesis models. We suggest that the future observations of {sup 9}Be in metal-poor stars may find enhanced abundances originating from metal-poor CR or flare activities.

  5. Cosmic rays: the spectrum and chemical composition from $10^{10}$ to $10^{20}$ eV

    E-Print Network [OSTI]

    Peixoto, C J Todero; Biermann, Peter L

    2015-01-01

    The production of energetic particles in the universe remains one of the great mysteries of modern science. The mechanisms of acceleration in astrophysical sources and the details about the propagation through the galactic and extragalactic media are still to be defined. In recent years, the cosmic ray flux has been measured with high precision in the energy range from \\energy{10} to \\energyEV{20.5} by several experiments using different techniques. In some energy ranges, it has been possible to determine the flux of individual elements (hydrogen to iron nuclei). This paper explores an astrophysical scenario in which only our Galaxy and the radio galaxy Cen A produce all particles measured on Earth in the energy range from \\energy{10} to \\energyEV{20.5}. Data from AMS-02, CREAM, KASCADE, KASCADE-Grande and the Pierre Auger Observatories are considered. The model developed here is able to describe the total and individual particle flux of all experiments considered. It is shown that the theory used here is abl...

  6. Positrons in Cosmic Rays from Dark Matter Annihilations for Uplifted Higgs Regions in MSSM

    E-Print Network [OSTI]

    Kenji Kadota; Katherine Freese; Paolo Gondolo

    2010-03-23

    We point out that there are regions in the MSSM parameter space which successfully provide a dark matter (DM) annihilation explanation for observed positron excess (e.g. PAMELA), while still remaining in agreement with all other data sets. Such regions (e.g. the uplifted Higgs region) can realize an enhanced neutralino DM annihilation dominantly into leptons via a Breit-Wigner resonance through the CP-odd Higgs channel. Such regions can give the proper thermal relic DM abundance, and the DM annihilation products are compatible with current antiproton and gamma ray observations. This scenario can succeed without introducing any additional degrees of freedom beyond those already in the MSSM.

  7. Constraints on the Cosmic-Ray Density Gradient Beyond the Solar Circle From

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing BacteriaConnect Collider Tests ofOExperiments (JournalFermi Gamma-Ray Observations

  8. Constraints on the Cosmic-Ray Density Gradient Beyond the Solar Circle From

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing BacteriaConnect Collider Tests ofOExperiments (JournalFermi Gamma-Ray

  9. THE BLAZAR SEQUENCE AND THE COSMIC GAMMA-RAY BACKGROUND RADIATION IN THE

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail. (Conference)Feedback SystemGimbaled X-Ray Head (Journal Article) |FERMI ERA (Journal

  10. arXiv:astro-ph/9706010v25Sep1997 Proc. 25th Int. Cosmic Ray Conference, Durban, 1997, v.4, p.257260

    E-Print Network [OSTI]

    Moskalenko, Igor V.

    . The basic spatial propagation mechanisms are (momentum-dependent) diffusion, convection, while in momentum space energy loss and diffusive reacceleration are treated. Fragmentation and energy losses are computed of this since it must be consistent with all types of observation. We emphasize also the use of realistic

  11. THE INTERPLANETARY NETWORK SUPPLEMENT TO THE FERMI GBM CATALOG OF COSMIC GAMMA-RAY BURSTS

    SciTech Connect (OSTI)

    Hurley, K. [University of California, Berkeley, Space Sciences Laboratory, 7 Gauss Way, Berkeley, CA 94720-7450 (United States); Pal'shin, V. D.; Aptekar, R. L.; Golenetskii, S. V.; Frederiks, D. D.; Mazets, E. P.; Svinkin, D. S. [Ioffe Physical Technical Institute, St. Petersburg 194021 (Russian Federation); Briggs, M. S.; Connaughton, V. [University of Alabama in Huntsville, NSSTC, 320 Sparkman Drive, Huntsville, AL 35805 (United States); Meegan, C. [Universities Space Research Association, NSSTC, 320 Sparkman Drive, Huntsville, AL 35805 (United States); Goldsten, J. [Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723 (United States); Boynton, W.; Fellows, C.; Harshman, K. [University of Arizona, Department of Planetary Sciences, Tucson, AZ 85721 (United States); Mitrofanov, I. G.; Golovin, D. V.; Kozyrev, A. S.; Litvak, M. L.; Sanin, A. B. [Space Research Institute, 84/32, Profsoyuznaya, Moscow 117997 (Russian Federation); Rau, A., E-mail: khurley@ssl.berkeley.edu [Max-Planck-Institut fuer extraterrestrische Physik, Giessenbachstrasse, Postfach 1312, D-85748 Garching (Germany); and others

    2013-08-15

    We present Interplanetary Network (IPN) data for the gamma-ray bursts in the first Fermi Gamma-Ray Burst Monitor (GBM) catalog. Of the 491 bursts in that catalog, covering 2008 July 12 to 2010 July 11, 427 were observed by at least one other instrument in the nine-spacecraft IPN. Of the 427, the localizations of 149 could be improved by arrival time analysis (or {sup t}riangulation{sup )}. For any given burst observed by the GBM and one other distant spacecraft, triangulation gives an annulus of possible arrival directions whose half-width varies between about 0.'4 and 32 Degree-Sign , depending on the intensity, time history, and arrival direction of the burst, as well as the distance between the spacecraft. We find that the IPN localizations intersect the 1{sigma} GBM error circles in only 52% of the cases, if no systematic uncertainty is assumed for the latter. If a 6 Degree-Sign systematic uncertainty is assumed and added in quadrature, the two localization samples agree about 87% of the time, as would be expected. If we then multiply the resulting error radii by a factor of three, the two samples agree in slightly over 98% of the cases, providing a good estimate of the GBM 3{sigma} error radius. The IPN 3{sigma} error boxes have areas between about 1 arcmin{sup 2} and 110 deg{sup 2}, and are, on the average, a factor of 180 smaller than the corresponding GBM localizations. We identify two bursts in the IPN/GBM sample that did not appear in the GBM catalog. In one case, the GBM triggered on a terrestrial gamma flash, and in the other, its origin was given as ''uncertain''. We also discuss the sensitivity and calibration of the IPN.

  12. Cosmic ray electron anisotropies as a tool to discriminate between exotic and astrophysical sources

    E-Print Network [OSTI]

    Cernuda, Ignacio

    2009-01-01

    Recent results from the PAMELA, ATIC, PPB BETS and Fermi collaborations extend the energy range in the electron flux measurement up to unexplored energies in the hundred GeVs range confirming the bump starting at about 10GeV already suggested by HEAT and AMS01 data . This bump can be explained by annihilating dark matter in the context of exotic physics, or by nearby astrophysical sources e.g. pulsars. In order to discriminate between competing models for primary positron production, the study of anisotropies ,complementary to the spectrum determination, shows up as new tool to look for the origin of the lepton excess. In this letter we calculate the contribution to the electron flux given by the collection of all known gamma ray pulsars (as listed in the ATNF catalogue) and by annihilating dark matter both in case of a clumpy halo or in case the excess can be atributed to a nearby sizeable dark matter clump. We address the problem of the electron anisotropy in both scenarios and estimate the prospect that a ...

  13. Emission of Cosmic Radio-waves, $X$- or $?$-rays by Moving Unstable Particles at Late Times

    E-Print Network [OSTI]

    K. Urbanowski

    2015-02-11

    A new quantum effect connected with the late time behavior of decaying states is described and its possible observational consequences are analyzed: It is shown that charged unstable particles as well as neutral unstable particles with non--zero magnetic moment which live sufficiently long may emit electromagnetic radiation. This mechanism is due to the nonclassical behavior of unstable particles at late times (at the post exponential time region). Analyzing the transition times region between exponential and non-exponential form of the survival amplitude it is found that the instantaneous energy of the unstable particle can take very large values, much larger than the energy of this state at times from the exponential time region. Based on the results obtained for the model considered, it is shown that this new purely quantum mechanical effect may be responsible for causing unstable particles produced by astrophysical sources and moving with relativistic velocities to emit electromagnetic--, $X$-- or $\\gamma$--rays at some time intervals from the transition time regions.

  14. A Model for Most Luminous and Long Duration Cosmic Gamma Ray Bursts

    E-Print Network [OSTI]

    Abhas Mitra

    1999-03-10

    We exploit the fact that General Theory of Relativity (GTR) predicts the existence of compact objects having surface gravitational redshift z_s burst rises dramatically with the value of z_c and can saturate to ~40%. This may explain a gamma ray burst of energy as high as ~5. 10**53 erg. By using the already existing detailed (Newtonian) calculations, it follows that the neutrino heating driven mass loss should be negligible, and the bulk Lorentz factor of the initial fireball could be ~1000. Most of the existing supernova calculations also show that it is extremely difficult to simulate the direct neutrino driven mass loss, and, the shock is not launched if the gravitational field becomes stronger. Since the gravitation potential well of the more compact NS is indded very deep, we do not expect additional baryonic mass ejection. So, without invoking any exotic physics (like strange stars) or overstretching any theory, we may explain most of the luminous GRBs in this simple model.

  15. Electromagnetic-ram action of the plasma focus as a paradigm for the production of gigantic galactic jets and cosmic rays

    SciTech Connect (OSTI)

    Bostick, W.

    1985-04-01

    A recent paper suggests that the electromagnetic-ram action of the plasma focus is trying to tell us how cosmic rays acquire their energy. It will be only natural for those theoretical astrophysicists who are steeped in statistical mechanics and turbulent processes, and who are now having a love affair with the black hole, to scoff at such a suggestion. But this author, undaunted, plunges even further into this cosmical question: he has the audacity to suggest further that the gigantic galactic jets in the active galaxies such as are now being observed by the computer-synthesized data of the radio signals at a number of wavelengths with the Very Large Array radio telescope in New Mexico, from radio galaxies like Cygnus A and Centaurus A (NGC 5128), are being produced by an electromagnetic-ram action similar to that of the plasma focus; and further, that this action is producing not only these spectacular jets, but also the acceleration of the cosmic ray at the same time in the same accelerating gap.

  16. Cosmic ray transport in heliospheric magnetic structures. I. Modeling background solar wind using the CRONOS magnetohydrodynamic code

    SciTech Connect (OSTI)

    Wiengarten, T.; Kleimann, J.; Fichtner, H.; Kühl, P.; Kopp, A.; Heber, B.; Kissmann, R.

    2014-06-10

    The transport of energetic particles such as cosmic rays is governed by the properties of the plasma being traversed. While these properties are rather poorly known for galactic and interstellar plasmas due to the lack of in situ measurements, the heliospheric plasma environment has been probed by spacecraft for decades and provides a unique opportunity for testing transport theories. Of particular interest for the three-dimensional (3D) heliospheric transport of energetic particles are structures such as corotating interaction regions, which, due to strongly enhanced magnetic field strengths, turbulence, and associated shocks, can act as diffusion barriers on the one hand, but also as accelerators of low energy CRs on the other hand as well. In a two-fold series of papers, we investigate these effects by modeling inner-heliospheric solar wind conditions with a numerical magnetohydrodynamic (MHD) setup (this paper), which will serve as an input to a transport code employing a stochastic differential equation approach (second paper). In this first paper, we present results from 3D MHD simulations with our code CRONOS: for validation purposes we use analytic boundary conditions and compare with similar work by Pizzo. For a more realistic modeling of solar wind conditions, boundary conditions derived from synoptic magnetograms via the Wang-Sheeley-Arge (WSA) model are utilized, where the potential field modeling is performed with a finite-difference approach in contrast to the traditional spherical harmonics expansion often utilized in the WSA model. Our results are validated by comparing with multi-spacecraft data for ecliptical (STEREO-A/B) and out-of-ecliptic (Ulysses) regions.

  17. Probing the cosmic gamma-ray burst rate with trigger simulations of the swift burst alert telescope

    SciTech Connect (OSTI)

    Lien, Amy; Cannizzo, John K. [Center for Research and Exploration in Space Science and Technology (CRESST) and NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Sakamoto, Takanori [Department of Physics and Mathematics, College of Science and Engineering, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara-shi, Kanagawa 252-5258 (Japan); Gehrels, Neil; Barthelmy, Scott D. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Palmer, David M. [Los Alamos National Laboratory, B244, Los Alamos, NM 87545 (United States); Graziani, Carlo [Astronomy Department, The University of Chicago, Chicago, IL 60637 (United States)

    2014-03-01

    The gamma-ray burst (GRB) rate is essential for revealing the connection between GRBs, supernovae, and stellar evolution. Additionally, the GRB rate at high redshift provides a strong probe of star formation history in the early universe. While hundreds of GRBs are observed by Swift, it remains difficult to determine the intrinsic GRB rate due to the complex trigger algorithm of Swift. Current studies of the GRB rate usually approximate the Swift trigger algorithm by a single detection threshold. However, unlike the previously flown GRB instruments, Swift has over 500 trigger criteria based on photon count rate and an additional image threshold for localization. To investigate possible systematic biases and explore the intrinsic GRB properties, we develop a program that is capable of simulating all the rate trigger criteria and mimicking the image threshold. Our simulations show that adopting the complex trigger algorithm of Swift increases the detection rate of dim bursts. As a result, our simulations suggest that bursts need to be dimmer than previously expected to avoid overproducing the number of detections and to match with Swift observations. Moreover, our results indicate that these dim bursts are more likely to be high redshift events than low-luminosity GRBs. This would imply an even higher cosmic GRB rate at large redshifts than previous expectations based on star formation rate measurements, unless other factors, such as the luminosity evolution, are taken into account. The GRB rate from our best result gives a total number of 4568{sub ?1429}{sup +825} GRBs per year that are beamed toward us in the whole universe.

  18. Perspective of monochromatic gamma-ray line detection with the High Energy cosmic-Radiation Detection (HERD) facility onboard China's Space Station

    E-Print Network [OSTI]

    Huang, Xiaoyuan; Tsai, Yue-Lin Sming; Xu, Ming; Yuan, Qiang; Chang, Jin; Dong, Yong-Wei; Hu, Bing-Liang; Lü, Jun-Guang; Wang, Le; Wu, Bo-Bing; Zhang, Shuang-Nan

    2015-01-01

    HERD is the High Energy cosmic-Radiation Detection instrument proposed to operate onboard China's space station in the 2020s. It is designed to detect energetic cosmic ray nuclei, leptons and photons with a high energy resolution ($\\sim1\\%$ for electrons and photons and $20\\%$ for nuclei) and a large geometry factor ($>3\\, m^2sr$ for electrons and diffuse photons and $>2\\, m^2sr$ for nuclei). In this work we discuss the capability of HERD to detect monochromatic $\\gamma$-ray lines, based on simulations of the detector performance. It is shown that HERD will be one of the most sensitive instruments for monochromatic $\\gamma$-ray searches at energies between $\\sim10$ to a few hundred GeV. Above hundreds of GeV, Cherenkov telescopes will be more sensitive due to their large effective area. As a specific example, we show that a good portion of the parameter space of a supersymmetric dark matter model can be probed with HERD.

  19. Mass composition of cosmic rays with energy above 10**17 eV according to surface detectors of the Yakutsk EAS array

    E-Print Network [OSTI]

    Glushkov, A V

    2014-01-01

    We discuss the lateral distribution of charged particles in extensive air showers with energy above $10^{17}$ eV measured by surface scintillation detectors of Yakutsk EAS array. The analysis covers the data obtained during the period from 1977 to 2013. Experimental values are compared to theoretical predictions obtained with the use of CORSIKA code within frameworks of different hadron interaction models. The best agreement between theory and experiment is observed for QGSJet01 and QGSJet-II-04 models. A change in the cosmic ray mass composition towards proton is observed in the energy range $(1-20) \\times 10^{17}$ eV.

  20. The IceCube Collaboration:contributions to the 30 th International Cosmic Ray Conference (ICRC 2007),

    E-Print Network [OSTI]

    Ackermann, M.; IceCube Collaboration

    2008-01-01

    variety of sources (gamma-ray bursts, active galac- ticgalactic nuclei or gamma-ray bursts [1, 2]. Instead ofnuclei (AGN) and gamma-ray bursts (GRB) are potential

  1. European Cosmic Ray Symposium

    ScienceCinema (OSTI)

    None

    2011-04-25

    13me Symposium qui se déroule du 27 au 31 juillet pour la premičre fois au Cern. Brian Pattison ouvre la cérémonie et donne la parole ŕ Dr.Ugland (qui représente le DG C.Rubbia excusé) et d'autres intervenants

  2. 30TH INTERNATIONAL COSMIC RAY CONFERENCE A Search for Prompt Very High Energy Emission from Satellite-detected Gamma-

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    Satellite-detected Gamma- ray Bursts using Milagro P. M. SAZ PARKINSON & B. L. DINGUS ˇ FOR THE MILAGRO@scipp.ucsc.edu; dingus@lanl.gov Abstract: Gamma-ray bursts (GRBs) have been detected up to GeV energies and are predicted of the Swift bursts. Introduction Almost 40 years after the detection of the first gamma-ray burst (GRB), many

  3. Mon. Not. R. Astron. Soc. 373, 643652 (2006) doi:10.1111/j.1365-2966.2006.11034.x Simulating field-aligned diffusion of a cosmic ray gas

    E-Print Network [OSTI]

    Brandenburg, Axel

    2006-01-01

    , Blegdamsvej 17, DK-2100 Copenhagen Ř, Denmark Accepted 2006 September 2. Received 2006 September 1. It is argued that energy equipartition between cosmic rays and other constituents of the interstellar medium by enhancing the buoyancy of magnetic structures in the interstellar gas. In the Sun, magnetic buoyancy drives

  4. First Result from the Alpha Magnetic Spectrometer on the International Space Station: Precision Measurement of the Positron Fraction in Primary Cosmic Rays of 0.5–350 GeV

    E-Print Network [OSTI]

    Basil, A.

    A precision measurement by the Alpha Magnetic Spectrometer on the International Space Station of the positron fraction in primary cosmic rays in the energy range from 0.5 to 350 GeV based on 6.8×10[superscript 6] positron ...

  5. Precision Measurement of the Proton Flux in Primary Cosmic Rays from Rigidity 1 GV to 1.8 TV with the Alpha Magnetic Spectrometer on the International Space Station

    E-Print Network [OSTI]

    Aguilar, M.

    A precise measurement of the proton flux in primary cosmic rays with rigidity (momentum/charge) from 1 GV to 1.8 TV is presented based on 300 million events. Knowledge of the rigidity dependence of the proton flux is ...

  6. Precision Measurement of the (e[superscript +] + e[superscript ?) Flux in Primary Cosmic Rays from 0.5 GeV to 1 TeV with the Alpha Magnetic Spectrometer on the International Space Station

    E-Print Network [OSTI]

    Aguilar, M.

    We present a measurement of the cosmic ray (e[superscript +] + e[superscript -]) flux in the range 0.5 GeV to 1 TeV based on the analysis of 10.6 million (e[superscript +] + e[superscript -]) events collected by AMS. The ...

  7. The geomagnetic eld tends to prevent low energy cosmic rays from impinging on the Earth's atmosphere. The east-west e ect on atmospheric neutrinos, a de cit in

    E-Print Network [OSTI]

    Tokyo, University of

    96M01070 10 2 24 #12;Abstract The geomagnetic eld tends to prevent low energy cosmic rays from impinging on the Earth's atmosphere. The east-west e ect on atmospheric neutrinos, a de cit in the number of positively charged particles with energies below a certain value cannot produce the secondaries. This cuto e

  8. Cloud Monitoring for Large Cosmic Ray Sites R.W. Clay, B.R. Dawson, R.T. Pace, D.S. Riordan, A.G.K. Smith, N.R. Wild

    E-Print Network [OSTI]

    OG 4.5.23 Cloud Monitoring for Large Cosmic Ray Sites R.W. Clay, B.R. Dawson, R.T. Pace, D monitoring of the cloud distribution in the night sky within the experimental fiducial volume. We have developed infra-red detectors which are capa- ble of responding to cloud in daytime or night-time. We

  9. NRL Release Number 06-1226-1945 PROC partition(VAR f:[int->nat], L:int, H:int, VAR P:int)

    E-Print Network [OSTI]

    :[int->nat], L:int, H:int, VAR P:int) f_save: [int->nat] = f; P_save: int = P; VAR lo, hi: int; VAR v: nat; L0: SKIP; L1: lo := L; L2: hi := H; L3: v := f(lo); L4: WHILE (hi > lo) DO L5: WHILE (f(hi) >= v & hi > lo) DO L6: hi := hi - 1; L7: ENDWHILE; L8: IF (hi > lo) THEN L9: f := f WITH [(lo) := f(hi), (hi) := v

  10. Neutrino and Cosmic-Ray Emission and Cumulative Background from Radiatively Inefficient Accretion Flows in Low-Luminosity Active Galactic Nuclei

    E-Print Network [OSTI]

    Shigeo S. Kimura; Kohta Murase; Kenji Toma

    2015-06-29

    We study high-energy neutrino and cosmic-ray (CR) emission from the cores of low-luminosity active galactic nuclei (LLAGN). In LLAGN, the thermalization of particles is expected to be incomplete in radiatively inefficient accretion flows (RIAFs), allowing the existence of non-thermal particles. In this work, assuming stochastic particle acceleration due to turbulence in RIAFs, we solve the Fokker-Planck equation and calculate spectra of escaping neutrinos and CRs. The RIAF in LLAGN can emit CR protons with $\\gtrsim10$ PeV energies and TeV-PeV neutrinos generated via $pp$ and/or $p\\gamma$ reactions. We find that, if $\\sim1$\\% of the accretion luminosity is carried away by non-thermal ions, the diffuse neutrino intensity from the cores of LLAGN may be as high as $E_\

  11. A Multi-Component Measurement of the Cosmic Ray Composition Between 10^{17} eV and 10^{18} eV

    E-Print Network [OSTI]

    T. Abu-Zayyad; K. Belov; D. J. Bird; J. Boyer; Z. Cao; M. Catanese; G. F. Chen; R. W. Clay; C. E. Covault; J. W. Cronin; H. Y. Dai; B. R. Dawson; J. W. Elbert; B. E. Fick; L. F. Fortson; J. W. Fowler; K. G. Gibbs; M. A. K. Glasmacher; K. D. Green; Y. Ho; A. Huang; C. C. Jui; M. J. Kidd; D. B. Kieda; B. C. Knapp; S. Ko; C. G. Larsen; W. Lee; E. C. Loh; E. J. Mannel; J. Matthews; J. N. Matthews; B. J. Newport; D. F. Nitz; R. A. Ong; K. M. Simpson; J. D. Smith; D. Sinclair; P. Sokolsky; P. Sommers; C. Song; J. K. K. Tang; S. B. Thomas; J. C. van der Velde; L. R. Wiencke; C. R. Wilkinson; S. Yoshida; X. Z. Zhang

    1999-11-09

    The average mass composition of cosmic rays with primary energies between $10^{17}$eV and $10^{18}$eV has been studied using a hybrid detector consisting of the High Resolution Fly's Eye (HiRes) prototype and the MIA muon array. Measurements have been made of the change in the depth of shower maximum, $X_{max}$, and in the change in the muon density at a fixed core location, $\\rho_\\mu(600m)$, as a function of energy. The composition has also been evaluated in terms of the combination of $X_{max}$ and $\\rho_\\mu(600m)$. The results show that the composition is changing from a heavy to lighter mix as the energy increases.

  12. The Design and Performance of a Scintillating-Fibre Tracker for the Cosmic-ray Muon Tomography of Legacy Nuclear Waste Containers

    E-Print Network [OSTI]

    Clarkson, Anthony; Hoek, Matthias; Ireland, David G; Johnstone, Russell; Kaiser, Ralf; Keri, Tibor; Lumsden, Scott; Mahon, David F; McKinnon, Bryan; Murray, Morgan; Nutbeam-Tuffs, Sian; Shearer, Craig; Staines, Cassie; Yang, Guangliang; Zimmerman, Colin

    2013-01-01

    Tomographic imaging techniques using the Coulomb scattering of cosmic-ray muons are increasingly being exploited for the non-destructive assay of shielded containers in a wide range of applications. One such application is the characterisation of legacy nuclear waste materials stored within industrial containers. The design, assembly and performance of a prototype muon tomography system developed for this purpose are detailed in this work. This muon tracker comprises four detection modules, each containing orthogonal layers of Saint-Gobain BCF-10 2mm-pitch plastic scintillating fibres. Identification of the two struck fibres per module allows the reconstruction of the incoming and Coulomb-scattered muon trajectories. These allow the container content, with respect to the atomic number Z of the scattering material, to be determined through reconstruction of the scattering location and magnitude. On each detection layer, the light emitted by the fibre is detected by a single Hamamatsu H8500 MAPMT with two fibre...

  13. GEANT4 Simulation of a Scintillating-Fibre Tracker for the Cosmic-ray Muon Tomography of Legacy Nuclear Waste Containers

    E-Print Network [OSTI]

    Clarkson, Anthony; Hoek, Matthias; Ireland, David G; Johnstone, Russell; Kaiser, Ralf; Keri, Tibor; Lumsden, Scott; Mahon, David F; McKinnon, Bryan; Murray, Morgan; Nutbeam-Tuffs, Sian; Shearer, Craig; Staines, Cassie; Yang, Guangliang; Zimmerman, Colin

    2013-01-01

    Cosmic-ray muons are highly penetrative charged particles that are observed at sea level with a flux of approximately one per square centimetre per minute. They interact with matter primarily through Coulomb scattering, which is exploited in the field of muon tomography to image shielded objects in a wide range of applications. In this paper, simulation studies are presented that assess the feasibility of a scintillating-fibre tracker system for use in the identification and characterisation of nuclear materials stored within industrial legacy waste containers. A system consisting of a pair of tracking modules above and a pair below the volume to be assayed is simulated within the GEANT4 framework using a range of potential fibre pitches and module separations. Each module comprises two orthogonal planes of fibres that allow the reconstruction of the initial and Coulomb-scattered muon trajectories. A likelihood-based image reconstruction algorithm has been developed that allows the container content to be det...

  14. Reply to 'Influence of cosmic ray variability on the monsoon rainfall and temperature': a false-positive in the field of solar-terrestrial research

    E-Print Network [OSTI]

    Laken, Benjamin A

    2015-01-01

    A litany of research has been published claiming strong solar influences on the Earth's weather and climate. Much of this work includes documented errors and false-positives, yet is still frequently used to substantiate arguments of global warming denial. This manuscript reports on a recent study by Badruddin & Aslam (2014), hereafter BA14, which claimed a highly significant ($p=1.4\\times10^{-5}$) relationship between extremes in the intensity of the Indian monsoon and the cosmic ray flux. They further speculated that the relationship they observed may apply across the entire tropical and sub-tropical belt, and be of global importance. However, their statistical analysis---and consequently their conclusions---were wrong. Specifically, their error resulted from an assumption that their data's underlying distribution was Gaussian. But, as demonstrated in this work, their data closely follow an ergodic chaotic distribution biased towards extreme values. From a probability density function, calculated using a...

  15. Color Glass Condensate in Brane Models or Don't Ultra High Energy Cosmic Rays Probe $10^{15}eV$ Scale ?

    E-Print Network [OSTI]

    Houri Ziaeepour

    2006-03-16

    In a previous work hep-ph/0203165 we have studied propagation of relativistic particles in the bulk for some of most popular brane models. Constraints have been put on the parameter space of these models by calculating the time delay due to propagation in the bulk of particles created during the interaction of Ultra High Energy Cosmic Rays with protons in the terrestrial atmosphere. The question was however raised that probability of hard processes in which bulk modes can be produced is small and consequently, the tiny flux of UHECRs can not constrain brane models. Here we use Color Glass Condensate (CGC) model to show that effects of extra dimensions are visible not only in hard processes when the incoming particle hits a massive Kaluza-Klein mode but also through the modification of soft/semi-hard parton distribution. At classical level, for an observer in the CM frame of UHECR and atmospheric hadrons, color charge sources are contracted to a thin sheet with a width inversely proportional to the energy of the ultra energetic cosmic ray hadron and consequently they can see an extra dimension with comparable size. Due to QCD interaction a short life swarm of partons is produced in front of the sheet and its partons can penetrate to the extra-dimension bulk. This reduces the effective density of partons on the brane or in a classical view creates a delay in the arrival of the most energetic particles if they are reflected back due to the warping of the bulk. In CGC approximation the density of swarm at different distance from the classical sheet can be related and therefore it is possible (at least formally) to determine the relative fraction of partons in the bulk and on the brane at different scales. Results of this work are also relevant to the test of brane models in hadron colliders like LHC.

  16. Gamma Ray Bursts

    E-Print Network [OSTI]

    Stahl, Bennett

    2014-01-01

    Olson. “Observations of gamma-ray bursts of cosmic origin. ”E. Lingenfelter. “Gamma-ray bursts. ” Annual Review of652-654. Waxman, Eli. “Gamma-ray-burst afterglow: supporting

  17. High Statistics Measurement of the Positron Fraction in Primary Cosmic Rays of 0.5–500 GeV with the Alpha Magnetic Spectrometer on the International Space Station

    E-Print Network [OSTI]

    Accardo, L; Aisa, D; Alpat, B; Alvino, A; Ambrosi, G; Andeen, K; Arruda, L; Attig, N; Azzarello, P; Bachlechner, A; Barao, F; Barrau, A; Barrin, L; Bartoloni, A; Basara, L; Battarbee, M; Battiston, R; Bazo, J; Becker, U; Behlmann, M; Beischer, B; Berdugo, J; Bertucci, B; Bigongiari, G; Bindi, V; Bizzaglia, S; Bizzarri, M; Boella, G; de Boer, W; Bollweg, K; Bonnivard, V; Borgia, B; Borsini, S; Boschini, M J; Bourquin, M; Burger, J; Cadoux, F; Cai, X D; Capell, M; Caroff, S; Carosi, G; Casaus, J; Cascioli, V; Castellini, G; Cernuda, I; Cerreta, D; Cervelli, F; Chae, M J; Chang, Y H; Chen, A I; Chen, H; Cheng, G M; Chen, H S; Cheng, L; Chikanian, A; Chou, H Y; Choumilov, E; Choutko, V; Chung, C H; Cindolo, F; Clark, C; Clavero, R; Coignet, G; Consolandi, C; Contin, A; Corti, C; Coste, B; Cui, Z; Dai, M; Delgado, C; Della Torre, S; Demirköz, M B; Derome, L; Di Falco, S; Di Masso, L; Dimiccoli, F; Díaz, C; von Doetinchem, P; Du, W J; Duranti, M; D’Urso, D; Eline, A; Eppling, F J; Eronen, T; Fan, Y Y; Farnesini, L; Feng, J; Fiandrini, E; Fiasson, A; Finch, E; Fisher, P; Galaktionov, Y; Gallucci, G; García, B; García-López, R; Gast, H; Gebauer, I; Gervasi, M; Ghelfi, A; Gillard, W; Giovacchini, F; Goglov, P; Gong, J; Goy, C; Grabski, V; Grandi, D; Graziani, M; Guandalini, C; Guerri, I; Guo, K H; Haas, D; Habiby, M; Haino, S; Han, K C; He, Z H; Heil, M; Henning, R; Hoffman, J; Hsieh, T H; Huang, Z C; Huh, C; Incagli, M; Ionica, M; Jang, W Y; Jinchi, H; Kanishev, K; Kim, G N; Kim, K S; Kirn, Th; Kossakowski, R; Kounina, O; Kounine, A; Koutsenko, V; Krafczyk, M S; Kunz, S; La Vacca, G; Laudi, E; Laurenti, G; Lazzizzera, I; Lebedev, A; Lee, H T; Lee, S C; Leluc, C; Levi, G; Li, H L; Li, J Q; Li, Q; Li, Q; Li, T X; Li, W; Li, Y; Li, Z H; Li, Z Y; Lim, S; Lin, C H; Lipari, P; Lippert, T; Liu, D; Liu, H; Lolli, M; Lomtadze, T; Lu, M J; Lu, Y S; Luebelsmeyer, K; Luo, F; Luo, J Z; Lv, S S; Majka, R; Malinin, A; Mańá, C; Marín, J; Martin, T; Martínez, G; Masi, N; Massera, F; Maurin, D; Menchaca-Rocha, A; Meng, Q; Mo, D C; Monreal, B; Morescalchi, L; Mott, P; Müller, M; Ni, J Q; Nikonov, N; Nozzoli, F; Nunes, P; Obermeier, A; Oliva, A; Orcinha, M; Palmonari, F; Palomares, C; Paniccia, M; Papi, A; Pauluzzi, M; Pedreschi, E; Pensotti, S; Pereira, R; Pilastrini, R; Pilo, F; Piluso, A; Pizzolotto, C; Plyaskin, V; Pohl, M; Poireau, V; Postaci, E; Putze, A; Quadrani, L; Qi, X M; Rancoita, P G; Rapin, D; Ricol, J S; Rodríguez, I; Rosier-Lees, S; Rossi, L; Rozhkov, A; Rozza, D; Rybka, G; Sagdeev, R; Sandweiss, J; Saouter, P; Sbarra, C; Schael, S; Schmidt, S M; Schuckardt, D; Schulz von Dratzig, A; Schwering, G; Scolieri, G; Seo, E S; Shan, B S; Shan, Y H; Shi, J Y; Shi, X Y; Shi, Y M; Siedenburg, T; Son, D; Spada, F; Spinella, F; Sun, W; Sun, W H; Tacconi, M; Tang, C P; Tang, X W; Tang, Z C; Tao, L; Tescaro, D; Ting, Samuel C C; Ting, S M; Tomassetti, N; Torsti, J; Türko?lu, C; Urban, T; Vagelli, V; Valente, E; Vannini, C; Valtonen, E; Vaurynovich, S; Vecchi, M; Velasco, M; Vialle, J P; Vitale, V; Volpini, G; Wang, L Q; Wang, Q L; Wang, R S; Wang, X; Wang, Z X; Weng, Z L; Whitman, K; Wienkenhöver, J; Wu, H; Wu, K Y; Xia, X; Xie, M; Xie, S; Xiong, R Q; Xin, G M; Xu, N S; Xu, W; Yan, Q; Yang, J; Yang, M; Ye, Q H; Yi, H; Yu, Y J; Yu, Z Q; Zeissler, S; Zhang, J H; Zhang, M T; Zhang, X B; Zhang, Z; Zheng, Z M; Zhou, F; Zhuang, H L; Zhukov, V; Zichichi, A; Zimmermann, N; Zuccon, P; Zurbach, C

    2014-01-01

    A precision measurement by AMS of the positron fraction in primary cosmic rays in the energy range from 0.5 to 500 GeV based on 10.9 million positron and electron events is presented. This measurement extends the energy range of our previous observation and increases its precision. The new results show, for the first time, that above ?200??GeV the positron fraction no longer exhibits an increase with energy.

  18. Searches for large-scale anisotropy in the arrival directions of cosmic rays detected above energy of 10{sup 19} eV at the Pierre Auger observatory and the telescope array

    SciTech Connect (OSTI)

    Aab, A.; Abreu, P.; Andringa, S.; Aglietta, M.; Ahn, E. J.; Al Samarai, I.; Albuquerque, I. F. M.; Allekotte, I.; Asorey, H.; Allen, J.; Allison, P.; Almela, A.; Castillo, J. Alvarez; Alvarez-Muńiz, J.; Batista, R. Alves; Ambrosio, M.; Aramo, C.; Aminaei, A.; Anchordoqui, L.; Arqueros, F.; Collaboration: Pierre Auger Collaboration; Telescope Array Collaboration; and others

    2014-10-20

    Spherical harmonic moments are well-suited for capturing anisotropy at any scale in the flux of cosmic rays. An unambiguous measurement of the full set of spherical harmonic coefficients requires full-sky coverage. This can be achieved by combining data from observatories located in both the northern and southern hemispheres. To this end, a joint analysis using data recorded at the Telescope Array and the Pierre Auger Observatory above 10{sup 19} eV is presented in this work. The resulting multipolar expansion of the flux of cosmic rays allows us to perform a series of anisotropy searches, and in particular to report on the angular power spectrum of cosmic rays above 10{sup 19} eV. No significant deviation from isotropic expectations is found throughout the analyses performed. Upper limits on the amplitudes of the dipole and quadrupole moments are derived as a function of the direction in the sky, varying between 7% and 13% for the dipole and between 7% and 10% for a symmetric quadrupole.

  19. Searches for Large-Scale Anisotropy in the Arrival Directions of Cosmic Rays Detected above Energy of $10^{19}$ eV at the Pierre Auger Observatory and the Telescope Array

    SciTech Connect (OSTI)

    Aab, Alexander; et al,

    2014-10-07

    Spherical harmonic moments are well-suited for capturing anisotropy at any scale in the flux of cosmic rays. An unambiguous measurement of the full set of spherical harmonic coefficients requires full-sky coverage. This can be achieved by combining data from observatories located in both the northern and southern hemispheres. To this end, a joint analysis using data recorded at the Telescope Array and the Pierre Auger Observatory above 1019 eV is presented in this work. The resulting multipolar expansion of the flux of cosmic rays allows us to perform a series of anisotropy searches, and in particular to report on the angular power spectrum of cosmic rays above 1019 eV. No significant deviation from isotropic expectations is found throughout the analyses performed. Upper limits on the amplitudes of the dipole and quadrupole moments are derived as a function of the direction in the sky, varying between 7% and 13% for the dipole and between 7% and 10% for a symmetric quadrupole.

  20. Measurement of the cosmic ray spectrum above $4{\\times}10^{18}$ eV using inclined events detected with the Pierre Auger Observatory

    E-Print Network [OSTI]

    The Pierre Auger Collaboration; Alexander Aab; Pedro Abreu; Marco Aglietta; Eun-Joo Ahn; Imen Al Samarai; Ivone Albuquerque; Ingomar Allekotte; Patrick Allison; Alejandro Almela; Jesus Alvarez Castillo; Jaime Alvarez-Muńiz; Rafael Alves Batista; Michelangelo Ambrosio; Amin Aminaei; Luis Anchordoqui; Sofia Andringa; Carla Aramo; Victor Manuel Aranda; Fernando Arqueros; Nicusor Arsene; Hernán Gonzalo Asorey; Pedro Assis; Julien Aublin; Maximo Ave; Michel Avenier; Gualberto Avila; Nafiun Awal; Alina Mihaela Badescu; Kerri B Barber; Julia Bäuml; Colin Baus; Jim Beatty; Karl Heinz Becker; Jose A Bellido; Corinne Berat; Mario Edoardo Bertaina; Xavier Bertou; Peter Biermann; Pierre Billoir; Simon G Blaess; Alberto Blanco; Miguel Blanco; Carla Bleve; Hans Blümer; Martina Bohá?ová; Denise Boncioli; Carla Bonifazi; Nataliia Borodai; Jeffrey Brack; Iliana Brancus; Ariel Bridgeman; Pedro Brogueira; William C Brown; Peter Buchholz; Antonio Bueno; Stijn Buitink; Mario Buscemi; Karen S Caballero-Mora; Barbara Caccianiga; Lorenzo Caccianiga; Marina Candusso; Laurentiu Caramete; Rossella Caruso; Antonella Castellina; Gabriella Cataldi; Lorenzo Cazon; Rosanna Cester; Alan G Chavez; Andrea Chiavassa; Jose Augusto Chinellato; Jiri Chudoba; Marco Cilmo; Roger W Clay; Giuseppe Cocciolo; Roberta Colalillo; Alan Coleman; Laura Collica; Maria Rita Coluccia; Ruben Conceiçăo; Fernando Contreras; Mathew J Cooper; Alain Cordier; Stephane Coutu; Corbin Covault; James Cronin; Richard Dallier; Bruno Daniel; Sergio Dasso; Kai Daumiller; Bruce R Dawson; Rogerio M de Almeida; Sijbrand J de Jong; Giuseppe De Mauro; Joao de Mello Neto; Ivan De Mitri; Jaime de Oliveira; Vitor de Souza; Luis del Peral; Olivier Deligny; Hans Dembinski; Niraj Dhital; Claudio Di Giulio; Armando Di Matteo; Johana Chirinos Diaz; Mary Lucia Díaz Castro; Francisco Diogo; Carola Dobrigkeit; Wendy Docters; Juan Carlos D'Olivo; Alexei Dorofeev; Qader Dorosti Hasankiadeh; Maria Teresa Dova; Jan Ebr; Ralph Engel; Martin Erdmann; Mona Erfani; Carlos O Escobar; Joao Espadanal; Alberto Etchegoyen; Heino Falcke; Ke Fang; Glennys Farrar; Anderson Fauth; Norberto Fazzini; Andrew P Ferguson; Mateus Fernandes; Brian Fick; Juan Manuel Figueira; Alberto Filevich; Andrej Filip?i?; Brendan Fox; Octavian Fratu; Martín Miguel Freire; Benjamin Fuchs; Toshihiro Fujii; Beatriz García; Diego Garcia-Pinto; Florian Gate; Hartmut Gemmeke; Alexandru Gherghel-Lascu; Piera Luisa Ghia; Ugo Giaccari; Marco Giammarchi; Maria Giller; Dariusz G?as; Christian Glaser; Henry Glass; Geraldina Golup; Mariano Gómez Berisso; Primo F Gómez Vitale; Nicolás González; Ben Gookin; Jacob Gordon; Alessio Gorgi; Peter Gorham; Philippe Gouffon; Nathan Griffith; Aurelio Grillo; Trent D Grubb; Fausto Guarino; Germano Guedes; Matías Rolf Hampel; Patricia Hansen; Diego Harari; Thomas A Harrison; Sebastian Hartmann; John Harton; Andreas Haungs; Thomas Hebbeker; Dieter Heck; Philipp Heimann; Alexander E Herve; Gary C Hill; Carlos Hojvat; Nicholas Hollon; Ewa Holt; Piotr Homola; Jörg Hörandel; Pavel Horvath; Miroslav Hrabovský; Daniel Huber; Tim Huege; Antonio Insolia; Paula Gina Isar; Ingolf Jandt; Stefan Jansen; Cecilia Jarne; Jeffrey A Johnsen; Mariela Josebachuili; Alex Kääpä; Olga Kambeitz; Karl Heinz Kampert; Peter Kasper; Igor Katkov; Balazs Kégl; Bianca Keilhauer; Azadeh Keivani; Ernesto Kemp; Roger Kieckhafer; Hans Klages; Matthias Kleifges; Jonny Kleinfeller; Raphael Krause; Nicole Krohm; Oliver Krömer; Daniel Kuempel; Norbert Kunka; Danielle LaHurd; Luca Latronico; Robert Lauer; Markus Lauscher; Pascal Lautridou; Sandra Le Coz; Didier Lebrun; Paul Lebrun; Marcelo Augusto Leigui de Oliveira; Antoine Letessier-Selvon; Isabelle Lhenry-Yvon; Katrin Link; Luis Lopes; Rebeca López; Aida López Casado; Karim Louedec; Lu Lu; Agustin Lucero; Max Malacari; Simone Maldera; Manuela Mallamaci; Jennifer Maller; Dusan Mandat; Paul Mantsch; Analisa Mariazzi; Vincent Marin; Ioana Mari?; Giovanni Marsella; Daniele Martello; Lilian Martin; Humberto Martinez; Oscar Martínez Bravo; Diane Martraire; Jimmy Masías Meza; Hermann-Josef Mathes; Sebastian Mathys; James Matthews; John Matthews; Giorgio Matthiae; Detlef Maurel; Daniela Maurizio; Eric Mayotte; Peter Mazur; Carlos Medina; Gustavo Medina-Tanco; Rebecca Meissner; Victor Mello; Diego Melo; Alexander Menshikov; Stefano Messina; Rishi Meyhandan; Maria Isabel Micheletti; Lukas Middendorf; Ignacio A Minaya; Lino Miramonti; Bogdan Mitrica; Laura Molina-Bueno; Silvia Mollerach; François Montanet; Carlo Morello; Miguel Mostafá; Celio A Moura; Marcio Aparecido Muller; Gero Müller; Sarah Müller

    2015-03-26

    A measurement of the cosmic-ray spectrum for energies exceeding $4{\\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\\gamma}$ with index $\\gamma=2.70 \\pm 0.02 \\,\\text{(stat)} \\pm 0.1\\,\\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\\text{s}=(5.12\\pm0.25\\,\\text{(stat)}^{+1.0}_{-1.2}\\,\\text{(sys)}){\\times}10^{19}$ eV.