National Library of Energy BETA

Sample records for webb space telescope

  1. James Webb Space Telescope: PM Lessons Applied - Eric Smith,...

    Energy Savers [EERE]

    James Webb Space Telescope: PM Lessons Applied - Eric Smith, Deputy Program Director, NASA James Webb Space Telescope: PM Lessons Applied - Eric Smith, Deputy Program Director,...

  2. Active galactic nucleus and quasar science with aperture masking interferometry on the James Webb Space Telescope

    SciTech Connect (OSTI)

    Ford, K. E. Saavik; McKernan, Barry; Sivaramakrishnan, Anand; Martel, André R.; Koekemoer, Anton; Lafrenière, David; Parmentier, Sébastien

    2014-03-10

    Due to feedback from accretion onto supermassive black holes (SMBHs), active galactic nuclei (AGNs) are believed to play a key role in ΛCDM cosmology and galaxy formation. However, AGNs extreme luminosities and the small angular size of their accretion flows create a challenging imaging problem. We show that the James Webb Space Telescope's Near Infrared Imager and Slitless Spectrograph (JWST-NIRISS) Aperture Masking Interferometry (AMI) mode will enable true imaging (i.e., without any requirement of prior assumptions on source geometry) at ∼65 mas angular resolution at the centers of AGNs. This is advantageous for studying complex extended accretion flows around SMBHs and in other areas of angular-resolution-limited astrophysics. By simulating data sequences incorporating expected sources of noise, we demonstrate that JWST-NIRISS AMI mode can map extended structure at a pixel-to-pixel contrast of ∼10{sup –2} around an L = 7.5 point source, using short exposure times (minutes). Such images will test models of AGN feedback, fueling, and structure (complementary with ALMA observations), and are not currently supported by any ground-based IR interferometer or telescope. Binary point source contrast with NIRISS is ∼10{sup –4} (for observing binary nuclei in merging galaxies), significantly better than current ground-based optical or IR interferometry. JWST-NIRISS's seven-hole non-redundant mask has a throughput of 15%, and utilizes NIRISS's F277W (2.77 μm), F380M (3.8 μm), F430M (4.3 μm), and F480M (4.8 μm) filters. NIRISS's square pixels are 65 mas per side, with a field of view ∼2' × 2'. We also extrapolate our results to AGN science enabled by non-redundant masking on future 2.4 m and 16 m space telescopes working at long-UV to near-IR wavelengths.

  3. Photo of the Week: The Webb Telescope's "Golden Spider" | Department of

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Energy The Webb Telescope's "Golden Spider" Photo of the Week: The Webb Telescope's "Golden Spider" September 14, 2012 - 2:32pm Addthis The James Webb Space Telescope is a large, infrared-optimized telescope that is anticipated to launch in 2018. The spider-like sheets and tubes of wires you see here are the Optical Telescope Simulator (OSIM) for the telescope itself. OSIM will help scientists prepare the Webb telescope for flight by generating a beam of light that the

  4. Thinking"" telescopes for autonomous space situational awareness...

    Office of Scientific and Technical Information (OSTI)

    Conference: Thinking"" telescopes for autonomous space situational awareness Citation Details In-Document Search Title: Thinking"" telescopes for autonomous space situational...

  5. Large aperture diffractive space telescope

    DOE Patents [OSTI]

    Hyde, Roderick A.

    2001-01-01

    A large (10's of meters) aperture space telescope including two separate spacecraft--an optical primary objective lens functioning as a magnifying glass and an optical secondary functioning as an eyepiece. The spacecraft are spaced up to several kilometers apart with the eyepiece directly behind the magnifying glass "aiming" at an intended target with their relative orientation determining the optical axis of the telescope and hence the targets being observed. The objective lens includes a very large-aperture, very-thin-membrane, diffractive lens, e.g., a Fresnel lens, which intercepts incoming light over its full aperture and focuses it towards the eyepiece. The eyepiece has a much smaller, meter-scale aperture and is designed to move along the focal surface of the objective lens, gathering up the incoming light and converting it to high quality images. The positions of the two space craft are controlled both to maintain a good optical focus and to point at desired targets which may be either earth bound or celestial.

  6. ABSOLUTE FLUX CALIBRATION OF THE IRAC INSTRUMENT ON THE SPITZER SPACE TELESCOPE USING HUBBLE SPACE TELESCOPE FLUX STANDARDS

    SciTech Connect (OSTI)

    Bohlin, R. C.; Gordon, K. D.; Deustua, S.; Ferguson, H. C.; Flanagan, K.; Kalirai, J.; Meixner, M.; Rieke, G. H.; Engelbracht, C.; Su, K. Y. L.; Ardila, D.; Tremblay, P.-E.

    2011-05-15

    The absolute flux calibration of the James Webb Space Telescope (JWST) will be based on a set of stars observed by the Hubble and Spitzer Space Telescopes. In order to cross-calibrate the two facilities, several A, G, and white dwarf stars are observed with both Spitzer and Hubble and are the prototypes for a set of JWST calibration standards. The flux calibration constants for the four Spitzer IRAC bands 1-4 are derived from these stars and are 2.3%, 1.9%, 2.0%, and 0.5% lower than the official cold-mission IRAC calibration of Reach et al., i.e., in agreement within their estimated errors of {approx}2%. The causes of these differences lie primarily in the IRAC data reduction and secondarily in the spectral energy distributions of our standard stars. The independent IRAC 8 {mu}m band-4 fluxes of Rieke et al. are about 1.5% {+-} 2% higher than those of Reach et al. and are also in agreement with our 8 {mu}m result.

  7. The Space-Based Telescopes for Actionable Refinement of Ephemeris...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: The Space-Based Telescopes for Actionable Refinement of Ephemeris Pathfinder Mission Citation Details In-Document Search Title: The Space-Based Telescopes for ...

  8. The Space-Based Telescopes for Actionable Refinement of Ephemeris...

    Office of Scientific and Technical Information (OSTI)

    Title: The Space-Based Telescopes for Actionable Refinement of Ephemeris Pathfinder Mission Authors: Simms, L ; De Vries, W ; RIot, V ; Olivier, S ; Pertica, A ; Bauman, B ; ...

  9. The Space-based Telescopes for Actionable Refinement of Ephemeris...

    Office of Scientific and Technical Information (OSTI)

    Title: The Space-based Telescopes for Actionable Refinement of Ephemeris (STARE) mission Authors: Riot, V ; Devries, W ; Bauman, B ; Simms, L ; Carter, D ; Phillion, D ; Olivier, S ...

  10. FIVE DEBRIS DISKS NEWLY REVEALED IN SCATTERED LIGHT FROM THE HUBBLE SPACE TELESCOPE NICMOS ARCHIVE

    SciTech Connect (OSTI)

    Soummer, Rémi; Perrin, Marshall D.; Pueyo, Laurent; Choquet, Élodie; Chen, Christine; Golimowski, David A.; Brendan Hagan, J.; Moerchen, Margaret; N'Diaye, Mamadou; Wolff, Schuyler; Debes, John; Hines, Dean C.; Mittal, Tushar; Rajan, Abhijith; Schneider, Glenn

    2014-05-10

    We have spatially resolved five debris disks (HD 30447, HD 35841, HD 141943, HD 191089, and HD 202917) for the first time in near-infrared scattered light by reanalyzing archival Hubble Space Telescope (HST)/NICMOS coronagraphic images obtained between 1999 and 2006. One of these disks (HD 202917) was previously resolved at visible wavelengths using the HST/Advanced Camera for Surveys. To obtain these new disk images, we performed advanced point-spread function subtraction based on the Karhunen-Loève Image Projection algorithm on recently reprocessed NICMOS data with improved detector artifact removal (Legacy Archive PSF Library And Circumstellar Environments (LAPLACE) Legacy program). Three of the disks (HD 30447, HD 35841, and HD 141943) appear edge-on, while the other two (HD 191089 and HD 202917) appear inclined. The inclined disks have been sculpted into rings; in particular, the disk around HD 202917 exhibits strong asymmetries. All five host stars are young (8-40 Myr), nearby (40-100 pc) F and G stars, and one (HD 141943) is a close analog to the young Sun during the epoch of terrestrial planet formation. Our discoveries increase the number of debris disks resolved in scattered light from 19 to 23 (a 21% increase). Given their youth, proximity, and brightness (V = 7.2-8.5), these targets are excellent candidates for follow-up investigations of planet formation at visible wavelengths using the HST/Space Telescope Imaging Spectrograph coronagraph, at near-infrared wavelengths with the Gemini Planet Imager and Very Large Telescope/SPHERE, and at thermal infrared wavelengths with the James Webb Space Telescope NIRCam and MIRI coronagraphs.

  11. Legacy extragalactic UV survey (LEGUS) with the Hubble space telescope. I. Survey description

    SciTech Connect (OSTI)

    Calzetti, D.; Andrews, J. E.; Lee, J. C.; Sabbi, E.; Ubeda, L.; Bright, S. N.; Aloisi, A.; Brown, T. M.; Christian, C.; Cignoni, M.; Adamo, A.; Smith, L. J.; Chandar, R.; Clayton, G. C.; Silva, R. da; Mink, S. E. de; Dobbs, C.; Elmegreen, B. G.; Elmegreen, D. M.; and others

    2015-02-01

    The Legacy ExtraGalactic UV Survey (LEGUS) is a Cycle 21 Treasury program on the Hubble Space Telescope aimed at the investigation of star formation and its relation with galactic environment in nearby galaxies, from the scales of individual stars to those of ∼kiloparsec-size clustered structures. Five-band imaging from the near-ultraviolet to the I band with the Wide-Field Camera 3 (WFC3), plus parallel optical imaging with the Advanced Camera for Surveys (ACS), is being collected for selected pointings of 50 galaxies within the local 12 Mpc. The filters used for the observations with the WFC3 are F275W(λ2704 Å), F336W(λ3355 Å), F438W(λ4325 Å), F555W(λ5308 Å), and F814W(λ8024 Å); the parallel observations with the ACS use the filters F435W(λ4328 Å), F606W(λ5921 Å), and F814W(λ8057 Å). The multiband images are yielding accurate recent (≲50 Myr) star formation histories from resolved massive stars and the extinction-corrected ages and masses of star clusters and associations. The extensive inventories of massive stars and clustered systems will be used to investigate the spatial and temporal evolution of star formation within galaxies. This will, in turn, inform theories of galaxy evolution and improve the understanding of the physical underpinning of the gas–star formation relation and the nature of star formation at high redshift. This paper describes the survey, its goals and observational strategy, and the initial scientific results. Because LEGUS will provide a reference survey and a foundation for future observations with the James Webb Space Telescope and with ALMA, a large number of data products are planned for delivery to the community.

  12. SLAC All Access: Fermi Gamma-ray Space Telescope

    ScienceCinema (OSTI)

    Romani, Roger

    2014-06-24

    Three hundred and fifty miles overhead, the Fermi Gamma-ray Space Telescope silently glides through space. From this serene vantage point, the satellite's instruments watch the fiercest processes in the universe unfold. Pulsars spin up to 700 times a second, sweeping powerful beams of gamma-ray light through the cosmos. The hyperactive cores of distant galaxies spew bright jets of plasma. Far beyond, something mysterious explodes with unfathomable power, sending energy waves crashing through the universe. Stanford professor and KIPAC member Roger W. Romani talks about this orbiting telescope, the most advanced ever to view the sky in gamma rays, a form of light at the highest end of the energy spectrum that's created in the hottest regions of the universe.

  13. Fermi Gamma-Ray Space Telescope: High-Energy Results From the...

    Office of Scientific and Technical Information (OSTI)

    Gamma-Ray Space Telescope: High-Energy Results From the First Year Michelson, P.F.; KIPAC, Menlo Park; Atwood, W.B.; Ritz, S.; UC, Santa Cruz UC, Santa Cruz, Phys. Dept....

  14. THE DEEP BLUE COLOR OF HD 189733b: ALBEDO MEASUREMENTS WITH HUBBLE SPACE TELESCOPE/SPACE TELESCOPE IMAGING SPECTROGRAPH AT VISIBLE WAVELENGTHS

    SciTech Connect (OSTI)

    Evans, Thomas M.; Aigrain, Suzanne; Barstow, Joanna K.; Pont, Frederic; Sing, David K.; Desert, Jean-Michel; Knutson, Heather A.; Gibson, Neale; Heng, Kevin; Lecavelier des Etangs, Alain

    2013-08-01

    We present a secondary eclipse observation for the hot Jupiter HD 189733b across the wavelength range 290-570 nm made using the Space Telescope Imaging Spectrograph on the Hubble Space Telescope. We measure geometric albedos of A{sub g} = 0.40 {+-} 0.12 across 290-450 nm and A{sub g} < 0.12 across 450-570 nm at 1{sigma} confidence. The albedo decrease toward longer wavelengths is also apparent when using six wavelength bins over the same wavelength range. This can be interpreted as evidence for optically thick reflective clouds on the dayside hemisphere with sodium absorption suppressing the scattered light signal beyond {approx}450 nm. Our best-fit albedo values imply that HD 189733b would appear a deep blue color at visible wavelengths.

  15. High resolution telescope including an array of elemental telescopes aligned along a common axis and supported on a space frame with a pivot at its geometric center

    DOE Patents [OSTI]

    Norbert, Massie A.; Yale, Oster

    1992-01-01

    A large effective-aperture, low-cost optical telescope with diffraction-limited resolution enables ground-based observation of near-earth space objects. The telescope has a non-redundant, thinned-aperture array in a center-mount, single-structure space frame. It employes speckle interferometric imaging to achieve diffraction-limited resolution. The signal-to-noise ratio problem is mitigated by moving the wavelength of operation to the near-IR, and the image is sensed by a Silicon CCD. The steerable, single-structure array presents a constant pupil. The center-mount, radar-like mount enables low-earth orbit space objects to be tracked as well as increases stiffness of the space frame. In the preferred embodiment, the array has elemental telescopes with subaperture of 2.1 m in a circle-of-nine configuration. The telescope array has an effective aperture of 12 m which provides a diffraction-limited resolution of 0.02 arc seconds. Pathlength matching of the telescope array is maintained by a electro-optical system employing laser metrology. Speckle imaging relaxes pathlength matching tolerance by one order of magnitude as compared to phased arrays. Many features of the telescope contribute to substantial reduction in costs. These include eliminating the conventional protective dome and reducing on-site construction activities. The cost of the telescope scales with the first power of the aperture rather than its third power as in conventional telescopes.

  16. High resolution telescope including an array of elemental telescopes aligned along a common axis and supported on a space frame with a pivot at its geometric center

    DOE Patents [OSTI]

    Norbert, M.A.; Yale, O.

    1992-04-28

    A large effective-aperture, low-cost optical telescope with diffraction-limited resolution enables ground-based observation of near-earth space objects. The telescope has a non-redundant, thinned-aperture array in a center-mount, single-structure space frame. It employes speckle interferometric imaging to achieve diffraction-limited resolution. The signal-to-noise ratio problem is mitigated by moving the wavelength of operation to the near-IR, and the image is sensed by a Silicon CCD. The steerable, single-structure array presents a constant pupil. The center-mount, radar-like mount enables low-earth orbit space objects to be tracked as well as increases stiffness of the space frame. In the preferred embodiment, the array has elemental telescopes with subaperture of 2.1 m in a circle-of-nine configuration. The telescope array has an effective aperture of 12 m which provides a diffraction-limited resolution of 0.02 arc seconds. Pathlength matching of the telescope array is maintained by a electro-optical system employing laser metrology. Speckle imaging relaxes pathlength matching tolerance by one order of magnitude as compared to phased arrays. Many features of the telescope contribute to substantial reduction in costs. These include eliminating the conventional protective dome and reducing on-site construction activities. The cost of the telescope scales with the first power of the aperture rather than its third power as in conventional telescopes. 15 figs.

  17. Fermi Gamma-Ray Space Telescope: High-Energy Results From the First Year

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Fermi Gamma-Ray Space Telescope: High-Energy Results From the First Year Citation Details In-Document Search Title: Fermi Gamma-Ray Space Telescope: High-Energy Results From the First Year Authors: Michelson, P.F. ; /KIPAC, Menlo Park ; Atwood, W.B. ; Ritz, S. ; /UC, Santa Cruz /UC, Santa Cruz, Phys. Dept. Publication Date: 2013-06-20 OSTI Identifier: 1084278 Report Number(s): SLAC-PUB-15630 arXiv:1011.0213 DOE Contract Number: AC02-76SF00515 Resource

  18. From Flapping Birds to Space Telescopes: The Modern Science of Origami (BNL Women in Science Lecture)

    SciTech Connect (OSTI)

    Lang, Robert J

    2010-06-24

    During the 1990s, the development and application of mathematical techniques to origami revolutionized this centuries-old Japanese art of paper folding. In his talk, Lang will describe how geometric concepts led to the solution of a broad class of origami-folding problems. Conversely, algorithms and theorems of origami design have shed light on long-standing mathematical questions and have solved practical engineering problems. Lang will discuss how origami has led to huge space telescopes, safer airbags, and more.

  19. The Animated Gamma-ray Sky Revealed by the Fermi Gamma-ray Space Telescope

    ScienceCinema (OSTI)

    Isabelle Grenier

    2010-01-08

    The Fermi Gamma-ray Space Telescope has been observing the sky in gamma-rays since August 2008.  In addition to breakthrough capabilities in energy coverage (20 MeV-300 GeV) and angular resolution, the wide field of view of the Large Area Telescope enables observations of 20% of the sky at any instant, and of the whole sky every three hours. It has revealed a very animated sky with bright gamma-ray bursts flashing and vanishing in minutes, powerful active galactic nuclei flaring over hours and days, many pulsars twinkling in the Milky Way, and X-ray binaries shimmering along their orbit. Most of these variable sources had not been seen by the Fermi predecessor, EGRET, and the wealth of new data already brings important clues to the origin of the high-energy emission and particles powered by the compact objects. The telescope also brings crisp images of the bright gamma-ray emission produced by cosmic-ray interactions in the interstellar medium, thus allowing to measure the cosmic nuclei and electron spectra across the Galaxy, to weigh interstellar clouds, in particular in the dark-gas phase. The telescope sensitivity at high energy will soon provide useful constraints on dark-matter annihilations in a variety of environments. I will review the current results and future prospects of the Fermi mission.

  20. THE PECULIAR EXTINCTION LAW OF SN 2014J MEASURED WITH THE HUBBLE SPACE TELESCOPE

    SciTech Connect (OSTI)

    Amanullah, R.; Goobar, A.; Johansson, J.; Petrushevska, T.; Banerjee, D. P. K.; Venkataraman, V.; Joshi, V.; Ashok, N. M.; Cao, Y.; Kulkarni, S. R.; Kasliwal, M. M.; Nugent, P. E.; Stanishev, V.

    2014-06-20

    The wavelength dependence of the extinction of Type Ia SN 2014J in the nearby galaxy M82 has been measured using UV to near-IR photometry obtained with the Hubble Space Telescope, the Nordic Optical Telescope, and the Mount Abu Infrared Telescope. This is the first time that the reddening of an SN Ia is characterized over the full wavelength range of 0.2-2 μm. A total-to-selective extinction, R{sub V} ≥ 3.1, is ruled out with high significance. The best fit at maximum using a Galactic type extinction law yields R{sub V} = 1.4 ± 0.1. The observed reddening of SN 2014J is also compatible with a power-law extinction, A {sub λ}/A{sub V} = (λ/λ {sub V}) {sup p} as expected from multiple scattering of light, with p = –2.1 ± 0.1. After correcting for differences in reddening, SN 2014J appears to be very similar to SN 2011fe over the 14 broadband filter light curves used in our study.

  1. First light from the Vela pulsar with the Fermi Gamma-ray Space Telescope

    SciTech Connect (OSTI)

    Razzano, M.

    2009-04-08

    The Fermi Gamma-ray Space Telescope, launched in June 2008, is an international space mission entirely devoted to the study of the high-energy gamma rays from the Universe. The main instrument aboard Fermi is the Large Area Telescope (LAT), a pair conversion telescope equipped with the state-of-the art in gamma-ray detectors technology. Thanks to its large field of view and effective area, combined with its excellent timing capability, Fermi-LAT is a perfect instrument for probing physics of gamma-ray emission in pulsars. LAT is expected to discover tens of new pulsars, both radio-loud and radio-quiet (Geminga-like). Moreover, LAT will observe with unprecedented statistics the brightest pulsars, investigating the details of magnetospheric emission. The first two months of the mission have been focused on the commissioning and first light, during which the LAT firmly detected the six previously known EGRET gamma-ray pulsars. One of the main sources of interest during our first light observations has been the Vela pulsar, the brightest persistent source in the whole gamma-ray sky. Thanks to its brightness, the Vela pulsar is an ideal candidate for calibrating the LAT and testing its performance. In addition, observations of Vela will help answer many questions related to the physics of pulsar emission processes. We present here some recent results obtained by the LAT on the Vela pulsar, using high-quality timing solutions provided by radio observations carried out within the Fermi pulsar radio timing campaign.

  2. A New Approach to Space Situational Awareness using Small Ground-Based Telescopes

    SciTech Connect (OSTI)

    Anheier, Norman C.; Chen, Cliff S.

    2014-12-01

    This report discusses a new SSA approach evaluated by Pacific Northwest National Laboratory (PNNL) that may lead to highly scalable, small telescope observing stations designed to help manage the growing space surveillance burden. Using the methods and observing tools described in this report, the team was able to acquire and track very faint satellites (near Pluto’s apparent brightness). Photometric data was collected and used to correlate object orbital position as a function of atomic clock-derived time. Object apparent brightness was estimated by image analysis and nearby star calibration. The measurement performance was only limited by weather conditions, object brightness, and the sky glow at the observation site. In the future, these new SSA technologies and techniques may be utilized to protect satellite assets, detect and monitor orbiting debris fields, and support Outer Space Treaty monitoring and transparency.

  3. Near-infrared detection of WD 0806-661 B with the Hubble space telescope

    SciTech Connect (OSTI)

    Luhman, K. L.; Esplin, T. L.; Morley, C. V.; Burgasser, A. J.; Bochanski, J. J.

    2014-10-10

    WD 0806-661 B is one of the coldest known brown dwarfs (T {sub eff} = 300-345 K) based on previous mid-infrared photometry from the Spitzer Space Telescope. In addition, it is a benchmark for testing theoretical models of brown dwarfs because its age and distance are well constrained via its primary star (2 0.5 Gyr, 19.2 0.6 pc). We present the first near-infrared detection of this object, which has been achieved through F110W imaging (?Y + J) with the Wide Field Camera 3 on board the Hubble Space Telescope. We measure a Vega magnitude of m {sub 110} = 25.70 0.08, which implies J ? 25.0. When combined with the Spitzer photometry, our estimate of J helps to better define the empirical sequence of the coldest brown dwarfs in M {sub 4.5} versus J [4.5]. The positions of WD 0806-661 B and other Y dwarfs in that diagram are best matched by the cloudy models of Burrows et al. and the cloudless models of Saumon et al., both of which employ chemical equilibrium. The calculations by Morley et al. for 50% cloud coverage differ only modestly from the data. Spectroscopy would enable a more stringent test of the models, but based on our F110W measurement, such observations are currently possible only with Hubble, and would require at least ?10 orbits to reach a signal-to-noise ratio of ?5.

  4. Prototype secondary mirror assembly design for the space infrared telescope facility

    SciTech Connect (OSTI)

    Stier, M.; Duffy, M.; Gullapalli, S.; Rockwell, R.; Sileo, F.; Krim, M.

    1989-02-01

    The authors describe their design of a liquid helium temperature prototype secondary mirror assembly (PSMA) under development for the NASA Space Infrared Telescope Facility (SIRTF) program. The SIRTF secondary mirror assembly must operate below 4 K and provide the functions of highly precise 2-axis dynamic tilting (chopping) in addition to the conventional functions needed by the SIRTF observatory. Their PSMA design employs a fused quartz mirror kinematically attached at its center to an aluminium cruciform. The mirror/cruciform assembly is driven in tilt about its combined center of mass using a unique flexure pivot and a four-actuator control system with feedback provided by pairs of differential position sensors. The voice coil actuators are mounted on a second flexure-pivoted mass enhancing servo system stability and isolating the telescope from vibration-induced disturbances. The mirror/cruciform and the reaction mass are attached to opposite sides of an aluminum mounting plate whose dimensional characteristics are nominally identical to that of the aluminum flexure pivot material. The mounting plate is connected to the outer housing by a six degree of freedom focus and centering mechanism using pivoted actuation levers driven by lead screw/harmonic drive/stepper motor assemblies.

  5. MULTI-WAVELENGTH HUBBLE SPACE TELESCOPE PHOTOMETRY OF STELLAR POPULATIONS IN NGC 288

    SciTech Connect (OSTI)

    Piotto, G.; Milone, A. P.; Marino, A. F.; Jerjen, H.; Bedin, L. R.; Anderson, J.; Bellini, A.; Cassisi, S. E-mail: luigi.bedin@oapd.inaf.it E-mail: amarino@mso.anu.edu.au E-mail: jayander@stsci.edu E-mail: cassisi@oa-teramo.inaf.it

    2013-09-20

    We present new UV observations for NGC 288, taken with the WFC3 detector on board the Hubble Space Telescope, and combine them with existing optical data from the archive to explore the multiple-population phenomenon in this globular cluster (GC). The WFC3's UV filters have demonstrated an uncanny ability to distinguish multiple populations along all photometric sequences in GCs thanks to their exquisite sensitivity to the atmospheric changes that are telltale signs of second-generation enrichment. Optical filters, on the other hand, are more sensitive to stellar-structure changes related to helium enhancement. By combining both UV and optical data, we can measure the helium variation. We quantify this enhancement for NGC 288 and find that the variation is typical of what we have come to expect in other clusters.

  6. MOST SPACE TELESCOPE PHOTOMETRY OF THE 2010 JANUARY TRANSIT OF EXTRASOLAR PLANET HD80606b

    SciTech Connect (OSTI)

    Roberts, Jessica E.; Barnes, Jason W.; Rowe, Jason F.

    2013-01-01

    We present observations of the full 2010 January transit of HD80606b from the Canadian microsatellite, Microvariability and Oscillations of Stars. By employing a space-based telescope, we monitor the entire transit, thus limiting systematic errors that result from ground observations. We determine measurements for the planetary radius (R{sub p} = 0.987 {+-} 0.061 R {sub Jup}) and inclination (i = 89. Degree-Sign 283 {+-} 0.024) by constraining our fits with the observed parameters of different groups. Our measured mid-transit time of 2455210.6449 {+-} 0.0034 HJD is consistent with the 2010 Spitzer results and is 20 minutes earlier than predicted by groups who observed the 2009 June transit.

  7. CONFRONTING THREE-DIMENSIONAL TIME-DEPENDENT JET SIMULATIONS WITH HUBBLE SPACE TELESCOPE OBSERVATIONS

    SciTech Connect (OSTI)

    Staff, Jan E.; Niebergal, Brian P.; Ouyed, Rachid; Pudritz, Ralph E.; Cai, Kai

    2010-10-20

    We perform state-of-the-art, three-dimensional, time-dependent simulations of magnetized disk winds, carried out to simulation scales of 60 AU, in order to confront optical Hubble Space Telescope observations of protostellar jets. We 'observe' the optical forbidden line emission produced by shocks within our simulated jets and compare these with actual observations. Our simulations reproduce the rich structure of time-varying jets, including jet rotation far from the source, an inner (up to 400 km s{sup -1}) and outer (less than 100 km s{sup -1}) component of the jet, and jet widths of up to 20 AU in agreement with observed jets. These simulations when compared with the data are able to constrain disk wind models. In particular, models featuring a disk magnetic field with a modest radial spatial variation across the disk are favored.

  8. Improving the space surveillance telescope's performance using multi-hypothesis testing

    SciTech Connect (OSTI)

    Chris Zingarelli, J.; Cain, Stephen; Pearce, Eric; Lambour, Richard; Blake, Travis; Peterson, Curtis J. R.

    2014-05-01

    The Space Surveillance Telescope (SST) is a Defense Advanced Research Projects Agency program designed to detect objects in space like near Earth asteroids and space debris in the geosynchronous Earth orbit (GEO) belt. Binary hypothesis test (BHT) methods have historically been used to facilitate the detection of new objects in space. In this paper a multi-hypothesis detection strategy is introduced to improve the detection performance of SST. In this context, the multi-hypothesis testing (MHT) determines if an unresolvable point source is in either the center, a corner, or a side of a pixel in contrast to BHT, which only tests whether an object is in the pixel or not. The images recorded by SST are undersampled such as to cause aliasing, which degrades the performance of traditional detection schemes. The equations for the MHT are derived in terms of signal-to-noise ratio (S/N), which is computed by subtracting the background light level around the pixel being tested and dividing by the standard deviation of the noise. A new method for determining the local noise statistics that rejects outliers is introduced in combination with the MHT. An experiment using observations of a known GEO satellite are used to demonstrate the improved detection performance of the new algorithm over algorithms previously reported in the literature. The results show a significant improvement in the probability of detection by as much as 50% over existing algorithms. In addition to detection, the S/N results prove to be linearly related to the least-squares estimates of point source irradiance, thus improving photometric accuracy.

  9. Calibration of photo sensors for the space-based cosmic ray telescope JEM-EUSO

    SciTech Connect (OSTI)

    Karus, Michael

    2015-02-24

    In order to unveil the mystery of ultra-high energy cosmic rays (UHECRs), the planned fluorescence telescope JEM-EUSO (Extreme Universe Space Observatory on-board Japanese Experiment Module) will observe extensive air showers induced by UHECRs from the International Space Station (ISS) orbit with a huge acceptance. The JEM-EUSO instrument consists of Fresnel optics and a focal surface detector with 5000 multi-anode photomultiplier tubes (MAPMTs), 300000 channels in total. For fluorescence detection of cosmic rays it is essential to calibrate the detector pre-flight with utmost precision and to monitor the performance of the detector throughout the whole mission time. For that purpose a calibration stand on-ground was built to measure precisely the performance of Hamamatsu 64 pixel MAPMTs that are planned to be used for JEM-EUSO. To investigate the suitability of alternative detector devices, further research is done with state-of-the-art silicon photomultipliers (SiPMs), namely Hamamatsu multi-pixel photon counters (MPPCs). These will also be tested in the calibration stand and their performance can be compared to conventional photomultiplier tubes.

  10. HUBBLE SPACE TELESCOPE EMISSION-LINE GALAXIES AT z ∼ 2: THE MYSTERY OF NEON

    SciTech Connect (OSTI)

    Zeimann, Gregory R.; Ciardullo, Robin; Gebhardt, Henry; Gronwall, Caryl; Hagen, Alex; Trump, Jonathan R.; Bridge, Joanna S.; Luo, Bin; Schneider, Donald P.

    2015-01-01

    We use near-infrared grism spectroscopy from the Hubble Space Telescope to examine the strength of [Ne III] λ3869 relative to Hβ, [O II] λ3727, and [O III] λ5007 in 236 low-mass (7.5 ≲ log (M {sub *}/M {sub ☉}) ≲ 10.5) star-forming galaxies in the redshift range 1.90 < z < 2.35. By stacking the data by stellar mass, we show that the [Ne III]/[O II] ratios of the z ∼ 2 universe are marginally higher than those seen in a comparable set of local Sloan Digital Sky Survey galaxies, and that [Ne III]/[O III] is enhanced by ∼0.2 dex. We consider the possible explanations for this ∼4σ result, including higher oxygen depletion out of the gas phase, denser H II regions, higher production of {sup 22}Ne via Wolf-Rayet stars, and the existence of a larger population of X-ray obscured active galactic nuclei at z ∼ 2 compared to z ∼ 0. None of these simple scenarios, alone, are favored to explain the observed line ratios. We conclude by suggesting several avenues of future observations to further explore the mystery of enhanced [Ne III] emission.

  11. A STUDY OF GRAVITATIONAL LENS CHROMATICITY WITH THE HUBBLE SPACE TELESCOPE

    SciTech Connect (OSTI)

    Munoz, J. A.; Mosquera, A. M.; Mediavilla, E.; Kochanek, C. S.; Falco, E. E.

    2011-12-01

    We report Hubble Space Telescope observations of six gravitational lenses with the Advanced Camera for Surveys. We measured the flux ratios between the lensed images in seven filters from 8140 #Angstrom# to 2200 #Angstrom#. In three of the systems, HE0512-3329, B1600+434, and H1413+117, we were able to construct UV extinction curves partially overlapping the 2175 #Angstrom# feature and characterize the properties of the dust relative to the Galaxy and the Magellanic Clouds. In HE1104-1804, we detect chromatic microlensing and use it to study the physical properties of the quasar accretion disk. For a Gaussian model of the disk exp (- r{sup 2}/2r{sup 2}{sub s}), scaling with wavelength as r{sub s} {proportional_to}{lambda}{sup p}, we estimate r{sub s} ({lambda}3363) = 4{sup +4}{sub -2} (7 {+-} 4) light days and p = 1.1 {+-} 0.6 (1.0 {+-} 0.6) for a logarithmic (linear) prior on r{sub s} . The remaining two systems, FBQ0951+2635 and SBS1520+530, yielded no useful estimates of extinction or chromatic microlensing.

  12. YOUNG PLANETARY NEBULAE: HUBBLE SPACE TELESCOPE IMAGING AND A NEW MORPHOLOGICAL CLASSIFICATION SYSTEM

    SciTech Connect (OSTI)

    Sahai, Raghvendra; Villar, Gregory G.; Morris, Mark R.

    2011-04-15

    Using Hubble Space Telescope images of 119 young planetary nebulae (PNs), most of which have not previously been published, we have devised a comprehensive morphological classification system for these objects. This system generalizes a recently devised system for pre-planetary nebulae, which are the immediate progenitors of PNs. Unlike previous classification studies, we have focused primarily on young PNs rather than all PNs, because the former best show the influences or symmetries imposed on them by the dominant physical processes operating at the first and primary stage of the shaping process. Older PNs develop instabilities, interact with the ambient interstellar medium, and are subject to the passage of photoionization fronts, all of which obscure the underlying symmetries and geometries imposed early on. Our classification system is designed to suffer minimal prejudice regarding the underlying physical causes of the different shapes and structures seen in our PN sample, however, in many cases, physical causes are readily suggested by the geometry, along with the kinematics that have been measured in some systems. Secondary characteristics in our system, such as ansae, indicate the impact of a jet upon a slower-moving, prior wind; a waist is the signature of a strong equatorial concentration of matter, whether it be outflowing or in a bound Keplerian disk, and point symmetry indicates a secular trend, presumably precession, in the orientation of the central driver of a rapid, collimated outflow.

  13. OPTICAL PROPER MOTION MEASUREMENTS OF THE M87 JET: NEW RESULTS FROM THE HUBBLE SPACE TELESCOPE

    SciTech Connect (OSTI)

    Meyer, Eileen T.; Sparks, W. B.; Biretta, J. A.; Anderson, Jay; Sohn, Sangmo Tony; Van der Marel, Roeland P.; Norman, Colin; Nakamura, Masanori

    2013-09-10

    We report new results from a Hubble Space Telescope archival program to study proper motions in the optical jet of the nearby radio galaxy M87. Using over 13 yr of archival imaging, we reach accuracies below 0.1c in measuring the apparent velocities of individual knots in the jet. We confirm previous findings of speeds up to 4.5c in the inner 6'' of the jet, and report new speeds for optical components in the outer part of the jet. We find evidence of significant motion transverse to the jet axis on the order of 0.6c in the inner jet features, and superluminal velocities parallel and transverse to the jet in the outer knot components, with an apparent ordering of velocity vectors possibly consistent with a helical jet pattern. Previous results suggested a global deceleration over the length of the jet in the form of decreasing maximum speeds of knot components from HST-1 outward, but our results suggest that superluminal speeds persist out to knot C, with large differentials in very nearby features all along the jet. We find significant apparent accelerations in directions parallel and transverse to the jet axis, along with evidence for stationary features in knots D, E, and I. These results are expected to place important constraints on detailed models of kiloparsec-scale relativistic jets.

  14. Photometric and structural properties of NGC 6544: A combined VVV-Hubble space telescope study

    SciTech Connect (OSTI)

    Cohen, Roger E.; Mauro, Francesco; Geisler, Doug; Moni Bidin, Christian; Dotter, Aaron; Bonatto, Charles

    2014-07-01

    We combine archival Hubble Space Telescope imaging with wide-field near-infrared photometry to study the neglected metal-poor Galactic globular cluster NGC 6544. A high spatial resolution map of differential reddening over the inner portion of the cluster is constructed, revealing variations of up to half of the total reddening, and the resulting corrected color-magnitude diagrams reveal a sparse blue horizontal branch and centrally concentrated blue straggler population, verified via relative proper motions. Using the corrected photometry to investigate the cluster distance, reddening, and age via direct comparison to well-calibrated photometry of clusters with similar metallicities, we estimate (m M){sub 0} = 11.96, E(B V) = 0.79, and an age coeval with M13 to within the relevant uncertainties. Although our data are insufficient to place tight constraints on the reddening law toward NGC 6544, we find no strong evidence that it is non-standard at optical or near-infrared wavelengths. We also provide near-infrared fiducial sequences extending nearly 2 mag below the cluster main sequence turnoff, generated from a statistically decontaminated sample of cluster stars. Lastly, we redetermine the cluster center and construct a radial number density profile which is well fit by an atypically flat power law with a slope of about 1.7. We discuss this result, together with a flattened main sequence luminosity function and inverted mass function, in the context of mass segregation and tidal stripping via interactions with Milky Way potential.

  15. A LYMAN BREAK GALAXY IN THE EPOCH OF REIONIZATION FROM HUBBLE SPACE TELESCOPE GRISM SPECTROSCOPY

    SciTech Connect (OSTI)

    Rhoads, James E.; Malhotra, Sangeeta; Cohen, Seth; Zheng Zhenya; Stern, Daniel; Dickinson, Mark; Pirzkal, Norbert; Grogin, Norman; Koekemoer, Anton; Peth, Michael A.; Spinrad, Hyron; Reddy, Naveen; Hathi, Nimish; Budavari, Tamas; Ferreras, Ignacio; Gardner, Jonathan P.; Gronwall, Caryl; Haiman, Zoltan; Kuemmel, Martin; Meurer, Gerhardt; and others

    2013-08-10

    We present observations of a luminous galaxy at z = 6.573-the end of the reionization epoch-which has been spectroscopically confirmed twice. The first spectroscopic confirmation comes from slitless Hubble Space Telescope Advanced Camera for Surveys grism spectra from the PEARS survey (Probing Evolution And Reionization Spectroscopically), which show a dramatic continuum break in the spectrum at rest frame 1216 A. The second confirmation is done with Keck + DEIMOS. The continuum is not clearly detected with ground-based spectra, but high wavelength resolution enables the Ly{alpha} emission line profile to be determined. We compare the line profile to composite line profiles at z = 4.5. The Ly{alpha} line profile shows no signature of a damping wing attenuation, confirming that the intergalactic gas is ionized at z = 6.57. Spectra of Lyman breaks at yet higher redshifts will be possible using comparably deep observations with IR-sensitive grisms, even at redshifts where Ly{alpha} is too attenuated by the neutral intergalactic medium to be detectable using traditional spectroscopy from the ground.

  16. Hubble space telescope high-resolution imaging of Kepler small and cool exoplanet host stars

    SciTech Connect (OSTI)

    Gilliland, Ronald L.; Cartier, Kimberly M. S.; Wright, Jason T.; Adams, Elisabeth R.; Ciardi, David R.

    2015-01-01

    High-resolution imaging is an important tool for follow-up study of exoplanet candidates found via transit detection with the Kepler mission. We discuss here Hubble Space Telescope imaging with the WFC3 of 23 stars that host particularly interesting Kepler planet candidates based on their small size and cool equilibrium temperature estimates. Results include detections, exclusion of background stars that could be a source of false positives for the transits, and detection of physically associated companions in a number of cases providing dilution measures necessary for planet parameter refinement. For six Kepler objects of interest, we find that there is ambiguity regarding which star hosts the transiting planet(s), with potentially strong implications for planetary characteristics. Our sample is evenly distributed in G, K, and M spectral types. Albeit with a small sample size, we find that physically associated binaries are more common than expected at each spectral type, reaching a factor of 10 frequency excess in M. We document the program detection sensitivities, detections, and deliverables to the Kepler follow-up program archive.

  17. THE M31 VELOCITY VECTOR. I. HUBBLE SPACE TELESCOPE PROPER-MOTION MEASUREMENTS

    SciTech Connect (OSTI)

    Sohn, Sangmo Tony; Anderson, Jay; Van der Marel, Roeland P.

    2012-07-01

    We present the first proper-motion (PM) measurements for the galaxy M31. We obtained new V-band imaging data with the Hubble Space Telescope ACS/WFC and the WFC3/UVIS instruments of three fields: a spheroid field near the minor axis, an outer disk field along the major axis, and a field on the Giant Southern Stream. The data provide five to seven year time baselines with respect to pre-existing deep first-epoch observations of the same fields. We measure the positions of thousands of M31 stars and hundreds of compact background galaxies in each field. High accuracy and robustness is achieved by building and fitting a unique template for each individual object. The average PM for each field is obtained from the average motion of the M31 stars between the epochs with respect to the background galaxies. For the three fields, the observed PMs ({mu}{sub W}, {mu}{sub N}) are, in units of mas yr{sup -1}, (- 0.0458, -0.0376) {+-} (0.0165, 0.0154), (- 0.0533, -0.0104) {+-} (0.0246, 0.0244), and (- 0.0179, -0.0357) {+-} (0.0278, 0.0272), respectively. The ability to average over large numbers of objects and over the three fields yields a final displacement accuracy of a few thousandths of a pixel, corresponding to only 12 {mu}as yr{sup -1}. This is comparable to what has been achieved for other Local Group galaxies using Very Long Baseline Array observations of water masers. Potential systematic errors are controlled by an analysis strategy that corrects for detector charge transfer inefficiency, spatially and time-dependent geometric distortion, and point-spread function variations. The robustness of the PM measurements and uncertainties are supported by the fact that data from different instruments, taken at different times and with different telescope orientations, as well as measurements of different fields, all yield statistically consistent results. Papers II and III of this series explore the implications of the new measurements for our understanding of the history

  18. Webb County, Texas: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Apps Datasets Community Login | Sign Up Search Page Edit with form History Webb County, Texas: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates...

  19. The Lyman alpha reference sample. II. Hubble space telescope imaging results, integrated properties, and trends

    SciTech Connect (OSTI)

    Hayes, Matthew; stlin, Gran; Duval, Florent; Sandberg, Andreas; Guaita, Lucia; Melinder, Jens; Rivera-Thorsen, Thger; Adamo, Angela; Schaerer, Daniel; Verhamme, Anne; Orlitov, Ivana; Mas-Hesse, J. Miguel; Ot-Floranes, Hctor; Cannon, John M.; Pardy, Stephen; Atek, Hakim; Kunth, Daniel; Laursen, Peter; Herenz, E. Christian

    2014-02-10

    We report new results regarding the Ly? output of galaxies, derived from the Lyman Alpha Reference Sample, and focused on Hubble Space Telescope imaging. For 14 galaxies we present intensity images in Ly?, H?, and UV, and maps of H?/H?, Ly? equivalent width (EW), and Ly?/H?. We present Ly? and UV radial light profiles and show they are well-fitted by Srsic profiles, but Ly? profiles show indices systematically lower than those of the UV (n ? 1-2 instead of ? 4). This reveals a general lack of the central concentration in Ly? that is ubiquitous in the UV. Photometric growth curves increase more slowly for Ly? than the far ultraviolet, showing that small apertures may underestimate the EW. For most galaxies, however, flux and EW curves flatten by radii ?10 kpc, suggesting that if placed at high-z only a few of our galaxies would suffer from large flux losses. We compute global properties of the sample in large apertures, and show total Ly? luminosities to be independent of all other quantities. Normalized Ly? throughput, however, shows significant correlations: escape is found to be higher in galaxies of lower star formation rate, dust content, mass, and nebular quantities that suggest harder ionizing continuum and lower metallicity. Six galaxies would be selected as high-z Ly? emitters, based upon their luminosity and EW. We discuss the results in the context of high-z Ly? and UV samples. A few galaxies have EWs above 50 , and one shows f{sub esc}{sup Ly?} of 80%; such objects have not previously been reported at low-z.

  20. HUBBLE SPACE TELESCOPE IMAGING OF THE BINARY NUCLEUS OF THE PLANETARY NEBULA EGB 6

    SciTech Connect (OSTI)

    Liebert, James; Bond, Howard E.; Ciardullo, Robin; Dufour, P.; Meakes, Michael G.; Renzini, Alvio; Gianninas, A. E-mail: bond@stsci.edu E-mail: mgmeakes@gmail.com E-mail: alvio.renzini@oapd.inaf.it

    2013-05-20

    EGB 6 is an ancient, low-surface-brightness planetary nebula. The central star, also cataloged as PG 0950+139, is a very hot DAOZ white dwarf (WD) with an apparent M dwarf companion, unresolved from the ground but detected initially through excesses in the JHK bands. Its kinematics indicates membership in the Galactic disk population. Inside of EGB 6 is an extremely dense emission knot-completely unexpected since significant mass loss from the WD should have ceased {approx}10{sup 5} yr ago. The electron density of the compact nebula is very high (2.2 Multiplication-Sign 10{sup 6} cm{sup -3}), as indicated by collisional de-excitation of forbidden emission lines. Hubble Space Telescope imaging and grism spectroscopy are reported here. These resolve the WD and apparent dM companion-at a separation of 0.''166, or a projected 96{sub -45}{sup +204} AU at the estimated distance of 576{sub -271}{sup +1224} pc (using the V magnitude). Much to our surprise, we found that the compact emission nebula is superposed on the dM companion, far from the photoionizing radiation of the WD. Moreover, a striking mid-infrared excess has recently been reported in the Spitzer/IRAC and MIPS bands, best fit with two dust shells. The derived ratio L{sub IR}/L{sub WD} = 2.7 Multiplication-Sign 10{sup -4} is the largest yet found for any WD or planetary nucleus. The compact nebula has maintained its high density for over three decades. We discuss two possible explanations for the origin and confinement of the compact nebula, neither of which is completely satisfactory. This leaves the genesis and confinement of the compact nebula an astrophysical puzzle, yet similar examples appear in the literature.

  1. JET ROTATION INVESTIGATED IN THE NEAR-ULTRAVIOLET WITH THE HUBBLE SPACE TELESCOPE IMAGING SPECTROGRAPH

    SciTech Connect (OSTI)

    Coffey, Deirdre; Ray, Thomas P.; Rigliaco, Elisabetta; Bacciotti, Francesca; Eisloeffel, Jochen

    2012-04-20

    We present results of the second phase of our near-ultraviolet investigation into protostellar jet rotation using the Hubble Space Telescope Imaging Spectrograph. We obtain long-slit spectra at the base of five T Tauri jets to determine if there is a difference in radial velocity between the jet borders which may be interpreted as a rotation signature. These observations are extremely challenging and push the limits of current instrumentation, but have the potential to provide long-awaited observational support for the magnetocentrifugal mechanism of jet launching in which jets remove angular momentum from protostellar systems. We successfully detect all five jet targets (from RW Aur, HN Tau, DP Tau, and CW Tau) in several near-ultraviolet emission lines, including the strong Mg II doublet. However, only RW Aur's bipolar jet presents a sufficiently high signal-to-noise ratio to allow for analysis. The approaching jet lobe shows a difference of 10 km s{sup -1} in a direction which agrees with the disk rotation sense, but is opposite to previously published optical measurements for the receding jet. The near-ultraviolet difference is not found six months later, nor is it found in the fainter receding jet. Overall, in the case of RW Aur, differences are not consistent with a simple jet rotation interpretation. Indeed, given the renowned complexity and variability of this system, it now seems likely that any rotation signature is confused by other influences, with the inevitable conclusion that RW Aur is not suited to a jet rotation study.

  2. Hubble space telescope investigation of main-belt comet 133P/Elst-Pizarro

    SciTech Connect (OSTI)

    Jewitt, David; Ishiguro, Masateru; Weaver, Harold; Agarwal, Jessica; Mutchler, Max; Larson, Steven

    2014-05-01

    We report new observations of the prototype main-belt comet (active asteroid) 133P/Elst-Pizarro taken at high angular resolution using the Hubble Space Telescope. The object has three main components: (1) a point-like nucleus; (2) a long, narrow antisolar dust tail; and (3) a short, sunward anti-tail. There is no resolved coma. The nucleus has a mean absolute magnitude H{sub V} = 15.70 0.10 and a light curve range ?V = 0.42 mag, the latter corresponding to projected dimensions 3.6 5.4 km (axis ratio 1.5:1) at the previously measured geometric albedo of 0.05 0.02. We explored a range of continuous and impulsive emission models to simultaneously fit the measured surface brightness profile, width, and position angle of the antisolar tail. Preferred fits invoke protracted emission, over a period of 150 days or less, of dust grains following a differential power-law size distribution with index 3.25 ?q ? 3.5 and with a wide range of sizes. Ultra-low surface brightness dust projected in the sunward direction is a remnant from emission activity occurring in previous orbits, and consists of the largest (?cm-sized) particles. Ejection velocities of one-micron-sized particles are comparable to the ?1.8 m s{sup 1} gravitational escape speed of the nucleus, while larger particles are released at speeds less than the gravitational escape velocity. The observations are consistent with, but do not prove, a hybrid hypothesis in which mass loss is driven by gas drag from the sublimation of near-surface water ice, but escape is aided by centripetal acceleration from the rotation of the elongated nucleus. No plausible alternative hypothesis has been identified.

  3. HUBBLE SPACE TELESCOPE FAR ULTRAVIOLET SPECTROSCOPY OF THE RECURRENT NOVA T PYXIDIS

    SciTech Connect (OSTI)

    Godon, Patrick; Sion, Edward M. [Astronomy and Astrophysics, Villanova University, Villanova, PA 19085 (United States); Starrfield, Sumner [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); Livio, Mario; Williams, Robert E. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Woodward, Charles E. [Minnesota Institute for Astrophysics, University of Minnesota, Minneapolis, MN 55455 (United States); Kuin, Paul [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT (United Kingdom); Page, Kim L., E-mail: patrick.godon@villanova.edu, E-mail: edward.sion@villanova.edu, E-mail: sumner.starrfield@asu.edu, E-mail: mlivio@stsci.edu, E-mail: wms@stsci.edu, E-mail: chelsea@astro.umn.edu, E-mail: n.kuin@ucl.ac.uk, E-mail: klp5@leicester.ac.uk [Department of Physics and Astronomy, University of Leicester, Leicester, LE1 7RH (United Kingdom)

    2014-04-01

    With six recorded nova outbursts, the prototypical recurrent nova T Pyxidis (T Pyx) is the ideal cataclysmic variable system to assess the net change of the white dwarf mass within a nova cycle. Recent estimates of the mass ejected in the 2011 outburst ranged from a few ?10{sup 5} M {sub ?} to 3.3 10{sup 4} M {sub ?}, and assuming a mass accretion rate of 10{sup 8}-10{sup 7} M {sub ?}yr{sup 1} for 44yr, it has been concluded that the white dwarf in T Pyx is actually losing mass. Using NLTE disk modeling spectra to fit our recently obtained Hubble Space Telescope COS and STIS spectra, we find a mass accretion rate of up to two orders of magnitude larger than previously estimated. Our larger mass accretion rate is due mainly to the newly derived distance of T Pyx (4.8kpc, larger than the previous 3.5kpc estimate), our derived reddening of E(B V) = 0.35 (based on combined IUE and GALEX spectra), and NLTE disk modeling (compared to blackbody and raw flux estimates in earlier works). We find that for most values of the reddening (0.25 ? E(B V) ? 0.50) and white dwarf mass (0.70 M {sub ?} ? M {sub wd} ? 1.35 M {sub ?}) the accreted mass is larger than the ejected mass. Only for a low reddening (?0.25 and smaller) combined with a large white dwarf mass (0.9 M {sub ?} and larger) is the ejected mass larger than the accreted one. However, the best results are obtained for a larger value of reddening.

  4. MULTIWAVELENGTH PHOTOMETRY AND HUBBLE SPACE TELESCOPE SPECTROSCOPY OF THE OLD NOVA V842 CENTAURUS

    SciTech Connect (OSTI)

    Sion, Edward M. [Department of Astronomy and Astrophysics, Villanova University, 800 Lancaster Avenue, Villanova, PA 19085 (United States); Szkody, Paula; Mukadam, Anjum [Department of Astronomy, University of Washington, Seattle, WA 98195 (United States); Warner, Brian; Woudt, Patrick [Astrophysics, Cosmology and Gravity Centre, Department of Astronomy, University of Cape Town, Private Bag X3, Rondebosch 7701 (South Africa); Walter, Frederic [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794 (United States); Henden, Arne [AAVSO 49 Bay State Road, Cambridge, MA 02138 (United States); Godon, Patrick, E-mail: edward.sion@villanova.edu, E-mail: szkody@astro.washington.edu, E-mail: anjum@astro.washington.edu, E-mail: brian.warner@uct.ac.za, E-mail: pwoudt@ast.uct.ac.za, E-mail: frederick.walter@stonybrook.edu, E-mail: arne@aavso.edu [Department of Astronomy and Astrophysics, Villanova University, Villanova, PA 19085 (United States)

    2013-08-01

    We present ground-based optical and near infrared photometric observations and Hubble Space Telescope (HST) COS spectroscopic observations of the old nova V842 Cen (Nova Cen 1986). Analysis of the optical light curves reveals a peak at 56.5 {+-} 0.3 s with an amplitude of 8.9 {+-} 4.2 mma, which is consistent with the rotation of a magnetic white dwarf primary in V842 Cen that was detected earlier by Woudt et al., and led to its classification as an intermediate polar. However, our UV lightcurve created from the COS time-tag spectra does not show this periodicity. Our synthetic spectral analysis of an HST COS spectrum rules out a hot white dwarf photosphere as the source of the FUV flux. The best-fitting model to the COS spectrum is a full optically thick accretion disk with no magnetic truncation, a low disk inclination angle, low accretion rate and a distance less than half the published distance that was determined on the basis of interstellar sodium D line strengths. Truncated accretion disks with truncation radii of 3 R{sub wd} and 5 R{sub wd} yielded unsatisfactory agreement with the COS data. The accretion rate is unexpectedly low for a classical nova only 24 yr after the explosion when the accretion rate is expected to be high and the white dwarf should still be very hot, especially if irradiation of the donor star took place. Our low accretion rate is consistent with those derived from X-ray and ground-based optical data.

  5. Hubble space telescope near-ir transmission spectroscopy of the super-Earth HD 97658B

    SciTech Connect (OSTI)

    Knutson, Heather A.; Dragomir, Diana; Kreidberg, Laura; Bean, Jacob L.; Kempton, Eliza M.-R.; McCullough, P. R.; Fortney, Jonathan J.; Gillon, Michael; Homeier, Derek; Howard, Andrew W.

    2014-10-20

    Recent results from the Kepler mission indicate that super-Earths (planets with masses between 1-10 times that of the Earth) are the most common kind of planet around nearby Sun-like stars. These planets have no direct solar system analogue, and are currently one of the least well-understood classes of extrasolar planets. Many super-Earths have average densities that are consistent with a broad range of bulk compositions, including both water-dominated worlds and rocky planets covered by a thick hydrogen and helium atmosphere. Measurements of the transmission spectra of these planets offer the opportunity to resolve this degeneracy by directly constraining the scale heights and corresponding mean molecular weights of their atmospheres. We present Hubble Space Telescope near-infrared spectroscopy of two transits of the newly discovered transiting super-Earth HD 97658b. We use the Wide Field Camera 3's (WFC3) scanning mode to measure the wavelength-dependent transit depth in 30 individual bandpasses. Our averaged differential transmission spectrum has a median 1? uncertainty of 23 ppm in individual bins, making this the most precise observation of an exoplanetary transmission spectrum obtained with WFC3 to date. Our data are inconsistent with a cloud-free solar metallicity atmosphere at the 10? level. They are consistent at the 0.4? level with a flat line model, as well as effectively flat models corresponding to a metal-rich atmosphere or a solar metallicity atmosphere with a cloud or haze layer located at pressures of 10 mbar or higher.

  6. INFRARED SPECTROSCOPY OF COMET 73P/SCHWASSMANN-WACHMANN 3 USING THE SPITZER SPACE TELESCOPE

    SciTech Connect (OSTI)

    Sitko, Michael L.; Whitney, Barbara A.; Wolff, Michael J.; Lisse, Carey M.; Kelley, Michael S.; Polomski, Elisha F.; Lynch, David K.; Russell, Ray W.; Kimes, Robin L.; Harker, David E. E-mail: bwhitney@wisc.edu E-mail: carey.lisse@jhuapl.edu E-mail: epolomsk@uwec.edu E-mail: Ray.W.Russell@aero.org E-mail: dharker@ucsd.edu

    2011-09-15

    We have used the Spitzer Space Telescope Infrared Spectrograph (IRS) to observe the 5-37 {mu}m thermal emission of comet 73P/Schwassmann-Wachmann 3 (SW3), components B and C. We obtained low spectral resolution (R {approx} 100) data over the entire wavelength interval, along with images at 16 and 22 {mu}m. These observations provided an unprecedented opportunity to study nearly pristine material from the surface and what was until recently the interior of an ecliptic comet-the cometary surface having experienced only two prior perihelion passages, and including material that was totally fresh. The spectra were modeled using a variety of mineral types including both amorphous and crystalline components. We find that the degree of silicate crystallinity, {approx}35%, is somewhat lower than most other comets with strong emission features, while its abundance of amorphous carbon is higher. Both suggest that SW3 is among the most chemically primitive solar system objects yet studied in detail, and that it formed earlier or farther from the Sun than the bulk of the comets studied so far. The similar dust compositions of the two fragments suggest that these are not mineralogically heterogeneous, but rather uniform throughout their volumes. The best-fit particle size distribution for SW3B has a form dn/da {approx} a{sup -3.5}, close to that expected for dust in collisional equilibrium, while that for SW3C has dn/da {approx} a{sup -4.0}, as seen mostly in active comets with strong directed jets, such as C/1995 O1 Hale-Bopp. The total mass of dust in the comae plus nearby tail, extrapolated from the field of view of the IRS peak-up image arrays, is (3-5) x 10{sup 8} kg for B and (7-9) x 10{sup 8} kg for C. Atomic abundances derived from the spectral models indicate a depletion of O compared to solar photospheric values, despite the inclusion of water ice and gas in the models. Atomic C may be solar or slightly sub-solar, but its abundance is complicated by the potential

  7. Gamma-Ray Bursts as seen by the Fermi Gamma-Ray Space Telescope

    SciTech Connect (OSTI)

    Omodei, Nicola

    2009-04-08

    The Large Area Telescope (LAT) instrument on the Fermi mission is revealing the rich spectral and temporal gamma-ray burst phenomena in the >100 MeV band. The synergy with Fermi's GBM detectors links these observations to those in the well-explored 10-1000 keV range; the addition of the >100 MeV band observations brings new hint and new information about burst emission in both the prompt and afterglow phases. In this contribution we describe the prospects for the Fermi Large Area Telescope (LAT) in observing Gamma-Ray Bursts (GRBs), and some preliminary results. Here we focus our attention on the importance of multi frequencies approach to GRB science during the just began Fermi era.

  8. Design and Initial Tests of the Tracker-Converter ofthe Gamma-ray Large Area Space Telescope

    SciTech Connect (OSTI)

    Atwood, W.B.; Bagagli, R.; Baldini, L.; Bellazzini, R.; Barbiellini, G.; Belli, F.; Borden, T.; Brez, A.; Brigida, M.; Caliandro, G.A.; Cecchi, C.; Cohen-Tanugi, J.; De Angelis, A.; Drell, P.; Favuzzi, C.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Germani, S.; Giannitrapani, R.; Giglietto, N.; /UC, Santa Cruz /INFN, Pisa /Pisa U. /INFN, Trieste /INFN, Rome /Rome U.,Tor Vergata /SLAC /INFN, Bari /Bari U. /INFN, Perugia /Perugia U. /Udine U. /Hiroshima U. /NASA, Goddard /Maryland U. /Tokyo Inst. Tech. /INFN, Padua /Padua U. /Pisa, Scuola Normale Superiore

    2007-04-16

    The Tracker subsystem of the Large Area Telescope (LAT) science instrument of the Gamma-ray Large Area Space Telescope (GLAST) mission has been completed and tested. It is the central detector subsystem of the LAT and serves both to convert an incident gamma-ray into an electron-positron pair and to track the pair in order to measure the gamma-ray direction. It also provides the principal trigger for the LAT. The Tracker uses silicon strip detectors, read out by custom electronics, to detect charged particles. The detectors and electronics are packaged, along with tungsten converter foils, in 16 modular, high-precision carbon-composite structures. It is the largest silicon-strip detector system ever built for launch into space, and its aggressive design emphasizes very low power consumption, passive cooling, low noise, high efficiency, minimal dead area, and a structure that is highly transparent to charged particles. The test program has demonstrated that the system meets or surpasses all of its performance specifications as well as environmental requirements. It is now installed in the completed LAT, which is being prepared for launch in early 2008.

  9. Hubble space telescope absolute proper motions of NGC 6681 (M70) and the sagittarius dwarf spheroidal galaxy

    SciTech Connect (OSTI)

    Massari, D.; Ferraro, F. R.; Dalessandro, E.; Lanzoni, B.

    2013-12-10

    We have measured absolute proper motions for the three populations intercepted in the direction of the Galactic globular cluster NGC 6681: the cluster itself, the Sagittarius dwarf spheroidal galaxy, and the field. For this, we used Hubble Space Telescope ACS/WFC and WFC3/UVIS optical imaging data separated by a temporal baseline of 5.464 yr. Five background galaxies were used to determine the zero point of the absolute-motion reference frame. The resulting absolute proper motion of NGC 6681 is (?{sub ?}cos ?, ?{sub ?}) = (1.58 0.18, 4.57 0.16) mas yr{sup 1}. This is the first estimate ever made for this cluster. For the Sgr dSph we obtain (?{sub ?}cos ?, ?{sub ?}) = 2.54 0.18, 1.19 0.16) mas yr{sup 1}, consistent with previous measurements and with the values predicted by theoretical models. The absolute proper motion of the Galaxy population in our field of view is (?{sub ?}cos ?, ?{sub ?}) = ( 1.21 0.27, 4.39 0.26) mas yr{sup 1}. In this study we also use background Sagittarius Dwarf Spheroidal stars to determine the rotation of the globular cluster in the plane of the sky and find that NGC 6681 is not rotating significantly: v {sub rot} = 0.82 1.02 km s{sup 1} at a distance of 1' from the cluster center.

  10. HUBBLE SPACE TELESCOPE DETECTION OF THE DOUBLE PULSAR SYSTEM J07373039 IN THE FAR-ULTRAVIOLET

    SciTech Connect (OSTI)

    Durant, Martin; Kargaltsev, Oleg; Pavlov, George G. E-mail: kargaltsev@email.gwu.edu

    2014-03-01

    We report on detection of the double pulsar system J07373039 in the far-UV with the Advanced Camera for Surveys/Solar-blind Channel detector aboard Hubble Space Telescope. We measured the energy flux F = (4.6 1.0) 10{sup 17}ergcm{sup 2} s{sup 1} in the 1250-1550 band, which corresponds to the extinction-corrected luminosity L ? 1.5 10{sup 28}ergs{sup 1} for the distance d = 1.1kpc and a plausible reddening E(B V) = 0.1. If the detected emission comes from the entire surface of one of the neutron stars with a 13km radius, the surface blackbody temperature is in the range T ? (2-5) 10{sup 5}K for a reasonable range of interstellar extinction. Such a temperature requires an internal heating mechanism to operate in old neutron stars, or, less likely, it might be explained by heating of the surface of the less energetic Pulsar B by the relativistic wind of Pulsar A. If the far-ultraviolet emission is non-thermal (e.g., produced in the magnetosphere of Pulsar A), its spectrum exhibits a break between the UV and X-rays.

  11. Constraints on the binary properties of mid- to late T dwarfs from Hubble space telescope WFC3 observations

    SciTech Connect (OSTI)

    Aberasturi, M.; Solano, E.; Burgasser, A. J.; Mora, A.; Martín, E. L.; Reid, I. N.; Looper, D.

    2014-12-01

    We used Hubble Space Telescope/Wide Field Camera 3 (WFC3) observations of a sample of 26 nearby (≤20 pc) mid- to late T dwarfs to search for cooler companions and measure the multiplicity statistics of brown dwarfs (BDs). Tightly separated companions were searched for using a double point-spread-function-fitting algorithm. We also compared our detection limits based on simulations to other prior T5+ BD binary programs. No new wide or tight companions were identified, which is consistent with the number of known T5+ binary systems and the resolution limits of WFC3. We use our results to add new constraints to the binary fraction (BF) of T-type BDs. Modeling selection effects and adopting previously derived separation and mass ratio distributions, we find an upper limit total BF of <16% and <25% assuming power law and flat mass ratio distributions, respectively, which are consistent with previous results. We also characterize a handful of targets around the L/T transition.

  12. Constraints on the progenitor system of the type Ia supernova 2014J from pre-explosion Hubble space telescope imaging

    SciTech Connect (OSTI)

    Kelly, Patrick L.; Fox, Ori D.; Filippenko, Alexei V.; Shen, Ken J.; Zheng, WeiKang; Graham, Melissa L.; Tucker, Brad E.; Cenko, S. Bradley; Schaefer, Gail

    2014-07-20

    We constrain the properties of the progenitor system of the highly reddened Type Ia supernova (SN Ia) 2014J in Messier 82 (M82; d ? 3.5 Mpc). We determine the supernova (SN) location using Keck-II K-band adaptive optics images, and we find no evidence for flux from a progenitor system in pre-explosion near-ultraviolet through near-infrared Hubble Space Telescope (HST) images. Our upper limits exclude systems having a bright red giant companion, including symbiotic novae with luminosities comparable to that of RS Ophiuchi. While the flux constraints are also inconsistent with predictions for comparatively cool He-donor systems (T ? 35,000 K), we cannot preclude a system similar to V445 Puppis. The progenitor constraints are robust across a wide range of R{sub V} and A{sub V} values, but significantly greater values than those inferred from the SN light curve and spectrum would yield proportionally brighter luminosity limits. The comparatively faint flux expected from a binary progenitor system consisting of white dwarf stars would not have been detected in the pre-explosion HST imaging. Infrared HST exposures yield more stringent constraints on the luminosities of very cool (T < 3000 K) companion stars than was possible in the case of SN Ia 2011fe.

  13. Hubble space telescope and ground-based observations of the type Iax supernovae SN 2005hk and SN 2008A

    SciTech Connect (OSTI)

    McCully, Curtis; Jha, Saurabh W. [Department of Physics and Astronomy, Rutgers, the State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Foley, Ryan J. [Astronomy Department, University of Illinois at Urbana-Champaign, 1002 West Green Street, Urbana, IL 61801 (United States); Chornock, Ryan [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Holtzman, Jon A. [Department of Astronomy, MSC 4500, New Mexico State University, P.O. Box 30001, Las Cruces, NM 88003 (United States); Balam, David D. [Dominion Astrophysical Observatory, Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Branch, David [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States); Filippenko, Alexei V.; Ganeshalingam, Mohan; Li, Weidong [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Frieman, Joshua [Kavli Institute for Cosmological Physics and Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Fynbo, Johan; Leloudas, Giorgos [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Galbany, Lluis [Institut de Fsica d'Altes Energies, Universitat Autnoma de Barcelona, E-08193 Bellaterra (Barcelona) (Spain); Garnavich, Peter M. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Graham, Melissa L. [Las Cumbres Observatory Global Telescope Network, Goleta, CA 93117 (United States); Hsiao, Eric Y. [Carnegie Observatories, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile); Leonard, Douglas C., E-mail: cmccully@physics.rutgers.edu [Department of Astronomy, San Diego State University, San Diego, CA 92182 (United States); and others

    2014-05-10

    We present Hubble Space Telescope (HST) and ground-based optical and near-infrared observations of SN 2005hk and SN 2008A, typical members of the Type Iax class of supernovae (SNe). Here we focus on late-time observations, where these objects deviate most dramatically from all other SN types. Instead of the dominant nebular emission lines that are observed in other SNe at late phases, spectra of SNe 2005hk and 2008A show lines of Fe II, Ca II, and Fe I more than a year past maximum light, along with narrow [Fe II] and [Ca II] emission. We use spectral features to constrain the temperature and density of the ejecta, and find high densities at late times, with n{sub e} ? 10{sup 9} cm{sup 3}. Such high densities should yield enhanced cooling of the ejecta, making these objects good candidates to observe the expected 'infrared catastrophe', a generic feature of SN Ia models. However, our HST photometry of SN 2008A does not match the predictions of an infrared catastrophe. Moreover, our HST observations rule out a 'complete deflagration' that fully disrupts the white dwarf for these peculiar SNe, showing no evidence for unburned material at late times. Deflagration explosion models that leave behind a bound remnant can match some of the observed properties of SNe Iax, but no published model is consistent with all of our observations of SNe 2005hk and 2008A.

  14. Early-type galaxies at intermediate redshift observed with Hubble space telescope WFC3: perspectives on recent star formation

    SciTech Connect (OSTI)

    Rutkowski, Michael J.; Jeong, Hyunjin; Yi, Sukyoung K.; Cohen, Seth H.; Windhorst, Rogier A.; Kaviraj, Sugata; Ryan, Russell E. Jr.; Koekemoer, Anton; Hathi, Nimish P.; Dopita, Michael A.

    2014-12-01

    We present an analysis of the stellar populations of 102 visually selected early-type galaxies (ETGs) with spectroscopic redshifts (0.35 ? z ? 1.5) from observations in the Early Release Science program with the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). We fit one- and two-component synthetic stellar models to the ETGs UV-optical-near-IR spectral energy distributions and find that a large fraction (?40%) are likely to have experienced a minor (f{sub YC} ? 10% of stellar mass) burst of recent (t{sub YC} ? 1 Gyr) star formation. The measured age and mass fraction of the young stellar populations do not strongly trend with measurements of galaxy morphology. We note that massive (M > 10{sup 10.5} M {sub ?}) recent star-forming ETGs appear to have larger sizes. Furthermore, high-mass, quiescent ETGs identified with likely companions populate a distinct region in the size-mass parameter space, in comparison with the distribution of massive ETGs with evidence of recent star formation (RSF). We conclude that both mechanisms of quenching star formation in disk-like ETGs and (gas-rich, minor) merger activity contribute to the formation of young stars and the size-mass evolution of intermediate redshift ETGs. The number of ETGs for which we have both HST WFC3 panchromatic (especially UV) imaging and spectroscopically confirmed redshifts is relatively small, therefore, a conclusion about the relative roles of both of these mechanisms remains an open question.

  15. THE MASS OF HD 38529c FROM HUBBLE SPACE TELESCOPE ASTROMETRY AND HIGH-PRECISION RADIAL VELOCITIES

    SciTech Connect (OSTI)

    Benedict, G. Fritz; McArthur, Barbara E.; Bean, Jacob L.; Barnes, Rory; Harrison, Thomas E.; Hatzes, Artie; Martioli, Eder; Nelan, Edmund P.

    2010-05-15

    Hubble Space Telescope Fine Guidance Sensor astrometric observations of the G4 IV star HD 38529 are combined with the results of the analysis of extensive ground-based radial velocity (RV) data to determine the mass of the outermost of two previously known companions. Our new RVs obtained with the Hobby-Eberly Telescope and velocities from the Carnegie-California group now span over 11 yr. With these data we obtain improved RV orbital elements for both the inner companion, HD 38529b, and the outer companion, HD 38529c. We identify a rotational period of HD 38529 (P {sub rot} = 31.65 {+-} 0fd17) with Fine Guidance Sensor photometry. The inferred star spot fraction is consistent with the remaining scatter in velocities being caused by spot-related stellar activity. We then model the combined astrometric and RV measurements to obtain the parallax, proper motion, perturbation period, perturbation inclination, and perturbation size due to HD 38529c. For HD 38529c we find P = 2136.1 {+-} 0.3 d, perturbation semimajor axis {alpha} = 1.05 {+-} 0.06 mas, and inclination i = 48.{sup 0}3 {+-} 3.{sup 0}7. Assuming a primary mass M {sub *} = 1.48 M {sub sun}, we obtain a companion mass M{sub c} = 17.6{sup +1.5} {sub -1.2} M {sub Jup}, 3{sigma} above a 13 M {sub Jup} deuterium burning, brown dwarf lower limit. Dynamical simulations incorporating this accurate mass for HD 38529c indicate that a near-Saturn mass planet could exist between the two known companions. We find weak evidence of an additional low amplitude signal that can be modeled as a planetary-mass ({approx}0.17 M {sub Jup}) companion at P {approx}194 days. Including this component in our modeling lowers the error of the mass determined for HD 38529c. Additional observations (RVs and/or Gaia astrometry) are required to validate an interpretation of HD 38529d as a planetary-mass companion. If confirmed, the resulting HD 38529 planetary system may be an example of a 'Packed Planetary System'.

  16. HUBBLE SPACE TELESCOPE PROPER MOTION (HSTPROMO) CATALOGS OF GALACTIC GLOBULAR CLUSTERS. I. SAMPLE SELECTION, DATA REDUCTION, AND NGC7078 RESULTS

    SciTech Connect (OSTI)

    Bellini, A.; Anderson, J.; Van der Marel, R. P.; Watkins, L. L.; King, I. R.; Bianchini, P.; Chanam, J.; Chandar, R.; Cool, A. M.; Ferraro, F. R.; Massari, D.; Ford, H.

    2014-12-20

    We present the first study of high-precision internal proper motions (PMs) in a large sample of globular clusters, based on Hubble Space Telescope (HST) data obtained over the past decade with the ACS/WFC, ACS/HRC, and WFC3/UVIS instruments. We determine PMs for over 1.3 million stars in the central regions of 22 clusters, with a median number of ?60,000 stars per cluster. These PMs have the potential to significantly advance our understanding of the internal kinematics of globular clusters by extending past line-of-sight (LOS) velocity measurements to two- or three-dimensional velocities, lower stellar masses, and larger sample sizes. We describe the reduction pipeline that we developed to derive homogeneous PMs from the very heterogeneous archival data. We demonstrate the quality of the measurements through extensive Monte Carlo simulations. We also discuss the PM errors introduced by various systematic effects and the techniques that we have developed to correct or remove them to the extent possible. We provide in electronic form the catalog for NGC7078 (M 15), which consists of 77,837 stars in the central 2.'4. We validate the catalog by comparison with existing PM measurements and LOS velocities and use it to study the dependence of the velocity dispersion on radius, stellar magnitude (or mass) along the main sequence, and direction in the plane of the sky (radial or tangential). Subsequent papers in this series will explore a range of applications in globular-cluster science and will also present the PM catalogs for the other sample clusters.

  17. Atmospheric characterization of five hot Jupiters with the wide field Camera 3 on the Hubble space telescope

    SciTech Connect (OSTI)

    Ranjan, Sukrit; Charbonneau, David; Dsert, Jean-Michel; Madhusudhan, Nikku; Deming, Drake; Wilkins, Ashlee; Mandell, Avi M.

    2014-04-20

    We probe the structure and composition of the atmospheres of five hot Jupiter exoplanets using the Hubble Space Telescope Wide Field Camera 3 (WFC3) instrument. We use the G141 grism (1.1-1.7 ?m) to study TrES-2b, TrES-4b, and CoRoT-1b in transit; TrES-3b in secondary eclipse; and WASP-4b in both. This wavelength region includes a predicted absorption feature from water at 1.4 ?m, which we expect to be nondegenerate with the other molecules that are likely to be abundant for hydrocarbon-poor (e.g., solar composition) hot Jupiter atmospheres. We divide our wavelength regions into 10 bins. For each bin we produce a spectrophotometric light curve spanning the time of transit or eclipse. We correct these light curves for instrumental systematics without reference to an instrument model. For our transmission spectra, our mean 1? precision per bin corresponds to variations of 2.1, 2.8, and 3.0 atmospheric scale heights for TrES-2b, TrES-4b, and CoRoT-1b, respectively. We find featureless spectra for these three planets. We are unable to extract a robust transmission spectrum for WASP-4b. For our dayside emission spectra, our mean 1? precision per bin corresponds to a planet-to-star flux ratio of 1.5 10{sup 4} and 2.1 10{sup 4} for WASP-4b and TrES-3b, respectively. We combine these estimates with previous broadband measurements and conclude that for both planets isothermal atmospheres are disfavored. We find no signs of features due to water. We confirm that WFC3 is suitable for studies of transiting exoplanets, but in staring mode multivisit campaigns are necessary to place strong constraints on water abundance.

  18. Delayed star formation in isolated dwarf galaxies: Hubble space telescope star formation history of the Aquarius dwarf irregular

    SciTech Connect (OSTI)

    Cole, Andrew A.; Weisz, Daniel R.; Dolphin, Andrew E.; Skillman, Evan D.; McConnachie, Alan W.; Brooks, Alyson M.; Leaman, Ryan E-mail: drw@ucsc.edu E-mail: skillman@astro.umn.edu E-mail: abrooks@physics.rutgers.edu

    2014-11-01

    We have obtained deep images of the highly isolated (d = 1 Mpc) Aquarius dwarf irregular galaxy (DDO 210) with the Hubble Space Telescope Advanced Camera for Surveys. The resulting color-magnitude diagram (CMD) reaches more than a magnitude below the oldest main-sequence turnoff, allowing us to derive the star formation history (SFH) over the entire lifetime of the galaxy with a timing precision of ?10% of the lookback time. Using a maximum likelihood fit to the CMD we find that only ?10% of all star formation in Aquarius took place more than 10 Gyr ago (lookback time equivalent to redshift z ? 2). The star formation rate increased dramatically ?6-8 Gyr ago (z ? 0.7-1.1) and then declined until the present time. The only known galaxy with a more extreme confirmed delay in star formation is Leo A, a galaxy of similar M {sub H} {sub I}/M {sub *}, dynamical mass, mean metallicity, and degree of isolation. The delayed stellar mass growth in these galaxies does not track the mean dark matter accretion rate from CDM simulations. The similarities between Leo A and Aquarius suggest that if gas is not removed from dwarf galaxies by interactions or feedback, it can linger for several gigayears without cooling in sufficient quantity to form stars efficiently. We discuss possible causes for the delay in star formation including suppression by reionization and late-time mergers. We find reasonable agreement between our measured SFHs and select cosmological simulations of isolated dwarfs. Because star formation and merger processes are both stochastic in nature, delayed star formation in various degrees is predicted to be a characteristic (but not a universal) feature of isolated small galaxies.

  19. EXTINCTION AND DUST GEOMETRY IN M83 H II REGIONS: AN HUBBLE SPACE TELESCOPE/WFC3 STUDY

    SciTech Connect (OSTI)

    Liu, Guilin; Calzetti, Daniela; Hong, Sungryong; Whitmore, Bradley; Chandar, Rupali; O'Connell, Robert W.; Blair, William P.; Cohen, Seth H.; Kim, Hwihyun; Frogel, Jay A.

    2013-12-01

    We present Hubble Space Telescope/WFC3 narrow-band imaging of the starburst galaxy M83 targeting the hydrogen recombination lines (H?, H?, and Pa?), which we use to investigate the dust extinction in the H II regions. We derive extinction maps with 6pc spatial resolution from two combinations of hydrogen lines (H?/H? and H?/Pa?), and show that the longer wavelengths probe larger optical depths, with A{sub V} values larger by ?1mag than those derived from the shorter wavelengths. This difference leads to a factor ?2 discrepancy in the extinction-corrected H? luminosity, a significant effect when studying extragalactic H II regions. By comparing these observations to a series of simple models, we conclude that a large diversity of absorber/emitter geometric configurations can account for the data, implying a more complex physical structure than the classical foreground ''dust screen'' assumption. However, most data points are bracketed by the foreground screen and a model where dust and emitters are uniformly mixed. When averaged over large (?100-200pc) scales, the extinction becomes consistent with a ''dust screen'', suggesting that other geometries tend to be restricted to more local scales. Moreover, the extinction in any region can be described by a combination of the foreground screen and the uniform mixture model with weights of 1/3 and 2/3 in the center (?2kpc), respectively, and 2/3 and 1/3 for the rest of the disk. This simple prescription significantly improves the accuracy of the dust extinction corrections and can be especially useful for pixel-based analyses of galaxies similar to M83.

  20. Hubble space telescope observations of the afterglow, supernova, and host galaxy associated with the extremely bright GRB 130427A

    SciTech Connect (OSTI)

    Levan, A. J. [Department of Physics, University of Warwick, Coventry, CV4 7AL (United Kingdom); Tanvir, N. R.; Wiersema, K. [Department of Physics and Astronomy, University of Leicester, University Road, Leicester, LE1 7RH (United Kingdom); Fruchter, A. S.; Hounsell, R. A.; Graham, J. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Hjorth, J.; Fynbo, J. P. U. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Pian, E. [INAF, Trieste Astronomical Observatory, via G.B. Tiepolo 11, I-34143 Trieste (Italy); Mazzali, P. [Astrophysics Research Institute, Liverpool John Moores University, IC2 Liverpool Science Park 146 Brownlow Hill, Liverpool L3 5RF (United Kingdom); Perley, D. A. [Department of Astronomy, California Institute of Technology, MC 249-17, 1200 East California Blvd., Pasadena, CA 91125 (United States); Cano, Z. [Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Dunhagi 5, 107 Reykjavik (Iceland); Cenko, S. B. [Astrophysics Science Division, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, MD 20771 (United States); Kouveliotou, C. [Science and Technology Office, ZP12, NASA/Marshall Space Flight Center, Huntsville, AL 35812 (United States); Pe'er, A. [Department of Physics, University College Cork, Cork (Ireland); Misra, K., E-mail: a.j.levan@warwick.ac.uk [Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital-263 002 (India)

    2014-09-10

    We present Hubble Space Telescope (HST) observations of the exceptionally bright and luminous Swift gamma-ray burst (GRB), GRB 130427A. At z = 0.34, this burst affords an excellent opportunity to study the supernova (SN) and host galaxy associated with an intrinsically extremely luminous burst (E {sub iso} > 10{sup 54} erg): more luminous than any previous GRB with a spectroscopically associated SN. We use the combination of the image quality, UV capability, and invariant point-spread function of HST to provide the best possible separation of the afterglow, host, and SN contributions to the observed light ?17 rest-frame days after the burst, utilizing a host subtraction spectrum obtained one year later. Advanced Camera for Surveys grism observations show that the associated SN, SN 2013cq, has an overall spectral shape and luminosity similar to SN 1998bw (with a photospheric velocity, v {sub ph} ? 15, 000 km s{sup 1}). The positions of the bluer features are better matched by the higher velocity SN 2010bh (v {sub ph} ? 30, 000 km s{sup 1}), but this SN is significantly fainter and fails to reproduce the overall spectral shape, perhaps indicative of velocity structure in the ejecta. We find that the burst originated ?4 kpc from the nucleus of a moderately star forming (1 M {sub ?} yr{sup 1}), possibly interacting disk galaxy. The absolute magnitude, physical size, and morphology of this galaxy, as well as the location of the GRB within it, are also strikingly similar to those of GRB 980425/SN 1998bw. The similarity of the SNe and environment from both the most luminous and least luminous GRBs suggests that broadly similar progenitor stars can create GRBs across six orders of magnitude in isotropic energy.

  1. High resolution telescope

    DOE Patents [OSTI]

    Massie, Norbert A.; Oster, Yale

    1992-01-01

    A large effective-aperture, low-cost optical telescope with diffraction-limited resolution enables ground-based observation of near-earth space objects. The telescope has a non-redundant, thinned-aperture array in a center-mount, single-structure space frame. It employs speckle interferometric imaging to achieve diffraction-limited resolution. The signal-to-noise ratio problem is mitigated by moving the wavelength of operation to the near-IR, and the image is sensed by a Silicon CCD. The steerable, single-structure array presents a constant pupil. The center-mount, radar-like mount enables low-earth orbit space objects to be tracked as well as increases stiffness of the space frame. In the preferred embodiment, the array has elemental telescopes with subaperture of 2.1 m in a circle-of-nine configuration. The telescope array has an effective aperture of 12 m which provides a diffraction-limited resolution of 0.02 arc seconds. Pathlength matching of the telescope array is maintained by an electro-optical system employing laser metrology. Speckle imaging relaxes pathlength matching tolerance by one order of magnitude as compared to phased arrays. Many features of the telescope contribute to substantial reduction in costs. These include eliminating the conventional protective dome and reducing on-site construction activites. The cost of the telescope scales with the first power of the aperture rather than its third power as in conventional telescopes.

  2. A HUBBLE SPACE TELESCOPE/COSMIC ORIGINS SPECTROGRAPH SEARCH FOR WARM-HOT BARYONS IN THE Mrk 421 SIGHT LINE

    SciTech Connect (OSTI)

    Danforth, Charles W.; Stocke, John T.; Keeney, Brian A.; Penton, Steven V.; Shull, J. Michael; Yao Yangsen; Green, James C., E-mail: danforth@colorado.edu [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309 (United States)

    2011-12-10

    Thermally broadened Ly{alpha} absorbers (BLAs) offer an alternate method to using highly ionized metal absorbers (O VI, O VII, etc.) to probe the warm-hot intergalactic medium (WHIM, T = 10{sup 5}-10{sup 7} K). Until now, WHIM surveys via BLAs have been no less ambiguous than those via far-UV and X-ray metal-ion probes. Detecting these weak, broad features requires background sources with a well-characterized far-UV continuum and data of very high quality. However, a recent Hubble Space Telescope/Cosmic Origins Spectrograph (COS) observation of the z = 0.03 blazar Mrk 421 allows us to perform a metal-independent search for WHIM gas with unprecedented precision. The data have high signal-to-noise ratio (S/N Almost-Equal-To 50 per {approx}20 km s{sup -1} resolution element) and the smooth, power-law blazar spectrum allows a fully parametric continuum model. We analyze the Mrk 421 sight line for BLA absorbers, particularly for counterparts to the proposed O VII WHIM systems reported by Nicastro et al. based on Chandra/Low Energy Transmission Grating observations. We derive the Ly{alpha} profiles predicted by the X-ray observations. The S/N of the COS data is high (S/N Almost-Equal-To 25 pixel{sup -1}), but much higher S/N can be obtained by binning the data to widths characteristic of the expected BLA profiles. With this technique, we are sensitive to WHIM gas over a large (N{sub H}, T) parameter range in the Mrk 421 sight line. We rule out the claimed Nicastro et al. O VII detections at their nominal temperatures (T {approx} 1-2 Multiplication-Sign 10{sup 6} K) and metallicities (Z = 0.1 Z{sub Sun }) at {approx}> 2{sigma} level. However, WHIM gas at higher temperatures and/or higher metallicities is consistent with our COS non-detections.

  3. The potential for detecting gamma-ray burst afterglows from population III stars with the next generation of infrared telescopes

    SciTech Connect (OSTI)

    Macpherson, D. [ICRAR, University of Western Australia, Crawley, WA 6009 (Australia); Coward, D. M. [School of Physics, University of Western Australia, Crawley, WA 6009 (Australia); Zadnik, M. G., E-mail: damien.macpherson@icrar.org [Department of Imaging and Applied Physics, Curtin University, Perth, WA 6845 (Australia)

    2013-12-10

    We investigate the detectability of a proposed population of gamma-ray bursts (GRBs) from the collapse of Population III (Pop III) stars. The James Webb Space Telescope (JWST) and Space Infrared Telescope for Cosmology and Astrophysics (SPICA) will be able to observe the late time infrared afterglows. We have developed a new method to calculate their detectability, which takes into account the fundamental initial mass function and formation rates of Pop III stars, from which we find the temporal variability of the afterglows and ultimately the length of time JWST and SPICA can detect them. In the range of plausible Pop III GRB parameters, the afterglows are always detectable by these instruments during the isotropic emission, for a minimum of 55 days and a maximum of 3.7 yr. The average number of detectable afterglows will be 2.96 10{sup 5} per SPICA field of view (FOV) and 2.78 10{sup 6} per JWST FOV. These are lower limits, using a pessimistic estimate of Pop III star formation. An optimal observing strategy with SPICA could identify a candidate orphan afterglow in ?1.3 yr, with a 90% probability of confirmation with further detailed observations. A beamed GRB will align with the FOV of the planned GRB detector Energetic X-ray Imaging Survey Telescope once every 9 yr. Pop III GRBs will be more easily detected by their isotropic emissions (i.e., orphan afterglows) rather than by their prompt emissions.

  4. FIRST ULTRAVIOLET REFLECTANCE SPECTRA OF PLUTO AND CHARON BY THE HUBBLE SPACE TELESCOPE COSMIC ORIGINS SPECTROGRAPH: DETECTION OF ABSORPTION FEATURES AND EVIDENCE FOR TEMPORAL CHANGE

    SciTech Connect (OSTI)

    Stern, S. A.; Spencer, J. R.; Shinn, A. [Southwest Research Institute, 1050 Walnut Street, Boulder, CO 80302 (United States); Cunningham, N. J.; Hain, M. J., E-mail: astern@swri.edu [Nebraska Wesleyan University, 5000 Saint Paul Avenue, Lincoln, NE 68504 (United States)

    2012-01-15

    We have observed the mid-UV spectra of both Pluto and its large satellite, Charon, at two rotational epochs using the Hubble Space Telescope (HST) Cosmic Origins Spectrograph (COS) in 2010. These are the first HST/COS measurements of Pluto and Charon. Here we describe the observations and our reduction of them, and present the albedo spectra, average mid-UV albedos, and albedo slopes we derive from these data. These data reveal evidence for a strong absorption feature in the mid-UV spectrum of Pluto; evidence for temporal change in Pluto's spectrum since the 1990s is reported, and indirect evidence for a near-UV spectral absorption on Charon is also reported.

  5. NEAR-INFRARED IMAGING OF A z = 6.42 QUASAR HOST GALAXY WITH THE HUBBLE SPACE TELESCOPE WIDE FIELD CAMERA 3

    SciTech Connect (OSTI)

    Mechtley, M.; Windhorst, R. A.; Cohen, S. H.; Jansen, R. A.; Scannapieco, E.; Ryan, R. E.; Koekemoer, A. M.; Schneider, G.; Fan, X.; Hathi, N. P.; Keel, W. C.; Roettgering, H.; Schneider, D. P.; Strauss, M. A.; Yan, H. J.

    2012-09-10

    We report on deep near-infrared F125W (J) and F160W (H) Hubble Space Telescope Wide Field Camera 3 images of the z = 6.42 quasar J1148+5251 to attempt to detect rest-frame near-ultraviolet emission from the host galaxy. These observations included contemporaneous observations of a nearby star of similar near-infrared colors to measure temporal variations in the telescope and instrument point-spread function (PSF). We subtract the quasar point source using both this direct PSF and a model PSF. Using direct subtraction, we measure an upper limit for the quasar host galaxy of m{sub J} > 22.8 and m{sub H} > 23.0 AB mag (2 {sigma}). After subtracting our best model PSF, we measure a limiting surface brightness from 0.''3 to 0.''5 radius of {mu}{sub J} > 23.5 and {mu}{sub H} > 23.7 AB mag arcsec{sup -2} (2 {sigma}). We test the ability of the model subtraction method to recover the host galaxy flux by simulating host galaxies with varying integrated magnitude, effective radius, and Sersic index, and conducting the same analysis. These models indicate that the surface brightness limit ({mu}{sub J} > 23.5 AB mag arcsec{sup -2}) corresponds to an integrated upper limit of m{sub J} > 22-23 AB mag, consistent with the direct subtraction method. Combined with existing far-infrared observations, this gives an infrared excess log (IRX) > 1.0 and corresponding ultraviolet spectral slope {beta} > -1.2 {+-} 0.2. These values match those of most local luminous infrared galaxies, but are redder than those of almost all local star-forming galaxies and z {approx_equal} 6 Lyman break galaxies.

  6. A Bigger Chill | Jefferson Lab

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

    An artist's rendering of the James Webb Space Telescope. Image: NASA Ultracold ... designing a new refrigeration plant for NASA Johnson Space Center that will be used in ...

  7. A NEW CEPHEID DISTANCE TO THE GIANT SPIRAL M101 BASED ON IMAGE SUBTRACTION OF HUBBLE SPACE TELESCOPE/ADVANCED CAMERA FOR SURVEYS OBSERVATIONS

    SciTech Connect (OSTI)

    Shappee, Benjamin J.; Stanek, K. Z. E-mail: kstanek@astronomy.ohio-state.edu

    2011-06-01

    We accurately determine a new Cepheid distance to M101 (NGC 5457) using archival Hubble Space Telescope (HST)/Advanced Camera for Surveys V and I time series photometry of two fields within the galaxy. We make a slight modification to the ISIS image subtraction package to obtain optimal differential light curves from HST data. We discovered 827 Cepheids with periods between 3 and 80 days, the largest extragalactic sample of Cepheids observed with HST by a factor of two. With this large Cepheid sample, we find that the relative distance of M101 from the Large Magellanic Cloud is {Delta}{mu}{sub LMC} = 10.63 {+-} 0.04 (random) {+-} 0.06 (systematic) mag. If we use the geometrically determined maser distance to NGC 4258 as our distance anchor, the distance modulus of M101 is {mu}{sub 0} = 29.04 {+-} 0.05 (random) {+-} 0.18 (systematic) mag or D = 6.4 {+-} 0.2 (random) {+-} 0.5 (systematic) Mpc. The uncertainty is dominated by the maser distance estimate ({+-}0.15 mag), which should improve over the next few years. We determine a steep metallicity dependence, {gamma}, for our Cepheid sample through two methods, yielding {gamma} = -0.80 {+-} 0.21 (random) {+-} 0.06 (systematic) mag dex{sup -1} and {gamma} = -0.72{sup +0.22}{sub -0.25} (random) {+-} 0.06 (systematic) mag dex{sup -1}. We see marginal evidence for variations in the Wesenheit period-luminosity relation slope as a function of deprojected galactocentric radius. We also use the tip of the red giant branch method to independently determine the distance modulus to M101 of {mu}{sub 0} = 29.05 {+-} 0.06 (random) {+-} 0.12 (systematic) mag.

  8. INFRARED SPECTRAL ENERGY DISTRIBUTIONS OF SEYFERT GALAXIES: SPITZER SPACE TELESCOPE OBSERVATIONS OF THE 12 {mu}m SAMPLE OF ACTIVE GALAXIES

    SciTech Connect (OSTI)

    Gallimore, J. F.; Yzaguirre, A.; Jakoboski, J.; Stevenosky, M. J.; Axon, D. J.; O'Dea, C. P.; Robinson, A.; Baum, S. A.; Buchanan, C. L.; Elitzur, M.; Elvis, M.

    2010-03-01

    The mid-infrared spectral energy distributions (SEDs) of 83 active galaxies, mostly Seyfert galaxies, selected from the extended 12 {mu}m sample are presented. The data were collected using all three instruments, Infrared Array Camera (IRAC), Infrared Spectrograph (IRS), and Multiband Imaging Photometer for Spitzer (MIPS), aboard the Spitzer Space Telescope. The IRS data were obtained in spectral mapping mode, and the photometric data from IRAC and IRS were extracted from matched, 20'' diameter circular apertures. The MIPS data were obtained in SED mode, providing very low-resolution spectroscopy (R {approx} 20) between {approx}55 and 90 {mu}m in a larger, 20'' x 30'' synthetic aperture. We further present the data from a spectral decomposition of the SEDs, including equivalent widths and fluxes of key emission lines; silicate 10 {mu}m and 18 {mu}m emission and absorption strengths; IRAC magnitudes; and mid-far-infrared spectral indices. Finally, we examine the SEDs averaged within optical classifications of activity. We find that the infrared SEDs of Seyfert 1s and Seyfert 2s with hidden broad line regions (HBLRs, as revealed by spectropolarimetry or other technique) are qualitatively similar, except that Seyfert 1s show silicate emission and HBLR Seyfert 2s show silicate absorption. The infrared SEDs of other classes within the 12 {mu}m sample, including Seyfert 1.8-1.9, non-HBLR Seyfert 2 (not yet shown to hide a type 1 nucleus), LINER, and H II galaxies, appear to be dominated by star formation, as evidenced by blue IRAC colors, strong polycyclic aromatic hydrocarbon emission, and strong far-infrared continuum emission, measured relative to mid-infrared continuum emission.

  9. ULTRA-DEEP HUBBLE SPACE TELESCOPE IMAGING OF THE SMALL MAGELLANIC CLOUD: THE INITIAL MASS FUNCTION OF STARS WITH M {approx}< 1 M {sub Sun}

    SciTech Connect (OSTI)

    Kalirai, Jason S.; Anderson, Jay; Dotter, Aaron; Reid, I. Neill; Richer, Harvey B.; Fahlman, Gregory G.; Hansen, Brad M. S.; Rich, R. Michael; Hurley, Jarrod; Shara, Michael M. E-mail: jayander@stsci.edu E-mail: richer@astro.ubc.ca E-mail: hansen@astro.ucla.edu E-mail: jhurley@swin.edu.au

    2013-02-15

    We present a new measurement of the stellar initial mass function (IMF) based on ultra-deep, high-resolution photometry of >5000 stars in the outskirts of the Small Magellanic Cloud (SMC) galaxy. The Hubble Space Telescope (HST) Advanced Camera for Surveys observations reveal this rich, cospatial population behind the foreground globular cluster 47 Tuc, which we targeted for 121 HST orbits. The stellar main sequence of the SMC is measured in the F606W, F814W color-magnitude diagram down to {approx}30th magnitude, and is cleanly separated from the foreground star cluster population using proper motions. We simulate the SMC population by extracting stellar masses (single and unresolved binaries) from specific IMFs and converting those masses to luminosities in our bandpasses. The corresponding photometry for these simulated stars is drawn directly from a rich cloud of 4 million artificial stars, thereby accounting for the real photometric scatter and completeness of the data. Over a continuous and well-populated mass range of M = 0.37-0.93 M {sub Sun} (e.g., down to a {approx}75% completeness limit at F606W = 28.7), we demonstrate that the IMF is well represented by a single power-law form with slope {alpha} = -1.90 ({sup +0.15} {sub -0.10}) (3{sigma} error) (e.g., dN/dM{proportional_to} M {sup {alpha}}). This is shallower than the Salpeter slope of {alpha} = -2.35, which agrees with the observed stellar luminosity function at higher masses. Our results indicate that the IMF does not turn over to a more shallow power-law form within this mass range. We discuss implications of this result for the theory of star formation, the inferred masses of galaxies, and the (lack of a) variation of the IMF with metallicity.

  10. Hubble space telescope/cosmic origins spectrograph observations of the quasar Q0302–003: Probing the He II reionization epoch and QSO proximity effects

    SciTech Connect (OSTI)

    Syphers, David; Shull, J. Michael

    2014-03-20

    Q0302–003 (z = 3.2860 ± 0.0005) was the first quasar discovered that showed a He II Gunn-Peterson trough, a sign of incomplete helium reionization at z ≳ 2.9. We present its Hubble Space Telescope/Cosmic Origins Spectrograph far-UV medium-resolution spectrum, which resolves many spectral features for the first time, allowing study of the quasar itself, the intergalactic medium, and quasar proximity effects. Q0302–003 has a harder intrinsic extreme-UV spectral index than previously claimed, as determined from both a direct fit to the spectrum (yielding α{sub ν} ≈ –0.8) and the helium-to-hydrogen ion ratio in the quasar's line-of-sight proximity zone. Intergalactic absorption along this sightline shows that the helium Gunn-Peterson trough is largely black in the range 2.87 < z < 3.20, apart from ionization due to local sources, indicating that helium reionization has not completed at these redshifts. However, we tentatively report a detection of nonzero flux in the high-redshift trough when looking at low-density regions, but zero flux in higher-density regions. This constrains the He II fraction to be about 1% in the low-density intergalactic medium (IGM) and possibly a factor of a few higher in the IGM as a whole, suggesting helium reionization has progressed substantially by z ∼ 3.1. The Gunn-Peterson trough recovers to a He II Lyα forest at z < 2.87. We confirm a transmission feature due to the ionization zone around a z = 3.05 quasar just off the sightline, and resolve the feature for the first time. We discover a similar such feature possibly caused by a luminous z = 3.23 quasar further from the sightline, which suggests that this quasar has been luminous for >34 Myr.

  11. Merger-driven fueling of active galactic nuclei: Six dual and of AGNs discovered with Chandra and Hubble Space Telescope observations

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

    Comerford, Julia M.; Pooley, David; Barrows, R. Scott; Greene, Jenny E.; Zakamska, Nadia L.; Madejski, Greg M.; Cooper, Michael C.

    2015-06-19

    Dual active galactic nuclei (AGNs) and offset AGNs are kpc-scale separation supermassive black holes pairs created during galaxy mergers, where both or one of the black holes are AGNs, respectively. These dual and offset AGNs are valuable probes of the link between mergers and AGNs but are challenging to identify. Here we present Chandra/ACIS observations of 12 optically selected dual AGN candidates atmore » $$z\\lt 0.34$$, where we use the X-rays to identify AGNs. We also present Hubble Space Telescope/Wide Field Camera 3 observations of 10 of these candidates, which reveal any stellar bulges accompanying the AGNs. We discover a dual AGN system with separation $${\\rm \\Delta }x=2.2$$ kpc, where the two stellar bulges have coincident [O iii] λ5007 and X-ray sources. This system is an extremely minor merger (460:1) that may include a dwarf galaxy hosting an intermediate mass black hole. We also find six single AGNs, and five systems that are either dual or offset AGNs with separations $${\\rm \\Delta }x\\lt 10$$ kpc. Four of the six dual AGNs and dual/offset AGNs are in ongoing major mergers, and these AGNs are 10 times more luminous, on average, than the single AGNs in our sample. This hints that major mergers may preferentially trigger higher luminosity AGNs. Further, we find that confirmed dual AGNs have hard X-ray luminosities that are half of those of single AGNs at fixed [O III] λ5007 luminosity, on average. Lastly, this could be explained by high densities of gas funneled to galaxy centers during mergers, and emphasizes the need for deeper X-ray observations of dual AGN candidates.« less

  12. EMISSION-LINE GALAXIES FROM THE HUBBLE SPACE TELESCOPE PROBING EVOLUTION AND REIONIZATION SPECTROSCOPICALLY (PEARS) GRISM SURVEY. II. THE COMPLETE SAMPLE

    SciTech Connect (OSTI)

    Pirzkal, Nor; Rothberg, Barry; Ly, Chun; Grogin, Norman A.; Dahlen, Tomas; Noeske, Kai G.; Bellini, Andrea; Malhotra, Sangeeta; Rhoads, James E.; Cohen, Seth H.; Mechtley, Matthew; Windhorst, Rogier A.; Meurer, Gerhardt R.; Walsh, Jeremy R.; Hathi, Nimish P.; Holwerda, Benne W.; Straughn, Amber N.

    2013-07-20

    We present a full analysis of the Probing Evolution And Reionization Spectroscopically (PEARS) slitess grism spectroscopic data obtained with the Advanced Camera for Surveys on board Hubble Space Telescope. PEARS covers fields within both the Great Observatories Origins Deep Survey (GOODS) North and South fields, making it ideal as a random survey of galaxies, as well as the availability of a wide variety of ancillary observations complemented by the spectroscopic results. Using the PEARS data, we are able to identify star-forming galaxies (SFGs) within the redshift volume 0 < z < 1.5. Star-forming regions in the PEARS survey are pinpointed independently of the host galaxy. This method allows us to detect the presence of multiple emission-line regions (ELRs) within a single galaxy. We identified a total of 1162 H{alpha}, [O III], and/or [O II] emission lines in the PEARS sample of 906 galaxies to a limiting flux of {approx}10{sup -18} erg s{sup -1} cm{sup -2}. The ELRs have also been compared to the properties of the host galaxy, including morphology, luminosity, and mass. From this analysis, we find three key results: (1) the computed line luminosities show evidence of a flattening in the luminosity function with increasing redshift; (2) the star-forming systems show evidence of complex morphologies with star formation occurring predominantly within one effective (half-light) radius. However, the morphologies show no correlation with host stellar mass. (3) Also, the number density of SFGs with M{sub *} {>=} 10{sup 9} M{sub Sun} decreases by an order of magnitude at z {<=} 0.5 relative to the number at 0.5 < z < 0.9, supporting the argument of galaxy downsizing.

  13. A DEEP HUBBLE SPACE TELESCOPE SEARCH FOR ESCAPING LYMAN CONTINUUM FLUX AT z {approx} 1.3: EVIDENCE FOR AN EVOLVING IONIZING EMISSIVITY

    SciTech Connect (OSTI)

    Siana, Brian; Bridge, Carrie R.; Teplitz, Harry I.; Chary, Ranga-Ram; Colbert, James W.; Scarlata, Claudia; Ferguson, Henry C.; Brown, Thomas M.; Giavalisco, Mauro; Dickinson, Mark; De Mello, Duilia F.; Conselice, Christopher J.; Gardner, Jonathan P.

    2010-11-01

    We have obtained deep Hubble Space Telescope far-UV images of 15 starburst galaxies at z {approx} 1.3 in the GOODS fields to search for escaping Lyman continuum (LyC) photons. These are the deepest far-UV images (m{sub AB} = 28.7, 3{sigma}, 1'' diameter) over this large an area (4.83 arcmin{sup 2}) and provide some of the best escape fraction constraints for any galaxies at any redshift. We do not detect any individual galaxies, with 3{sigma} limits to the LyC ({approx}700 A) flux 50-149 times fainter (in f{sub {nu}}) than the rest-frame UV (1500 A) continuum fluxes. Correcting for the mean intergalactic medium (IGM) attenuation (factor {approx}2), as well as an intrinsic stellar Lyman break (factor {approx}3), these limits translate to relative escape fraction limits of f{sub esc,rel} < [0.03, 0.21]. The stacked limit is f{sub esc,rel}(3{sigma}) < 0.02. We use a Monte Carlo simulation to properly account for the expected distribution of line-of-sight IGM opacities. When including constraints from previous surveys at z {approx} 1.3 we find that, at the 95% confidence level, no more than 8% of star-forming galaxies at z {approx} 1.3 can have relative escape fractions greater than 0.50. Alternatively, if the majority of galaxies have low, but non-zero, escaping LyC, the escape fraction cannot be more than 0.04. In light of some evidence for strong LyC emission from UV-faint regions of Lyman break galaxies (LBGs) at z {approx} 3, we also stack sub-regions of our galaxies with different surface brightnesses and detect no significant LyC flux at the f{sub esc,rel} < 0.03 level. Both the stacked limits and the limits from the Monte Carlo simulation suggest that the average ionizing emissivity (relative to non-ionizing UV emissivity) at z {approx} 1.3 is significantly lower than has been observed in LBGs at z {approx} 3. If the ionizing emissivity of star-forming galaxies is in fact increasing with redshift, it would help to explain the high photoionization rates seen in

  14. EFFECTS OF DIFFUSE BACKGROUND EMISSION AND SOURCE CROWDING ON PHOTOMETRIC COMPLETENESS IN SPITZER SPACE TELESCOPE IRAC SURVEYS: THE GLIMPSE CATALOGS AND ARCHIVES

    SciTech Connect (OSTI)

    Kobulnicky, Henry A.; Alexander, Michael J.; Babler, Brian L.; Meade, Marilyn R.; Whitney, Barbara A.; Churchwell, Edward B. E-mail: malexan9@uwyo.edu E-mail: meade@astro.wisc.edu E-mail: ebc@astro.wisc.edu

    2013-07-01

    We characterize the completeness of point source lists from Spitzer Space Telescope surveys in the four Infrared Array Camera (IRAC) bandpasses, emphasizing the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) programs (GLIMPSE I, II, 3D, 360; Deep GLIMPSE) and their resulting point source Catalogs and Archives. The analysis separately addresses effects of incompleteness resulting from high diffuse background emission and incompleteness resulting from point source confusion (i.e., crowding). An artificial star addition and extraction analysis demonstrates that completeness is strongly dependent on local background brightness and structure, with high-surface-brightness regions suffering up to five magnitudes of reduced sensitivity to point sources. This effect is most pronounced at the IRAC 5.8 and 8.0 {mu}m bands where UV-excited polycyclic aromatic hydrocarbon emission produces bright, complex structures (photodissociation regions). With regard to diffuse background effects, we provide the completeness as a function of stellar magnitude and diffuse background level in graphical and tabular formats. These data are suitable for estimating completeness in the low-source-density limit in any of the four IRAC bands in GLIMPSE Catalogs and Archives and some other Spitzer IRAC programs that employ similar observational strategies and are processed by the GLIMPSE pipeline. By performing the same analysis on smoothed images we show that the point source incompleteness is primarily a consequence of structure in the diffuse background emission rather than photon noise. With regard to source confusion in the high-source-density regions of the Galactic Plane, we provide figures illustrating the 90% completeness levels as a function of point source density at each band. We caution that completeness of the GLIMPSE 360/Deep GLIMPSE Catalogs is suppressed relative to the corresponding Archives as a consequence of rejecting stars that lie in the point

  15. U.S. Department of Energy ENVIRONMENTAL MANAGEMENT ADVISORY BOARD

    Office of Environmental Management (EM)

    ... overall project management performance results Lessons learned - NASA James Webb Space Telescope (NASA) Project Management Institute view on the pulse of the industry and ...

  16. ENVIRONMENTAL MANAGEMENT ADVISORY BOARD U.S. DEPARTMENT OF ENERGY

    Office of Environmental Management (EM)

    ... overall project management performance results Lessons learned - NASA James Webb Space Telescope (NASA) Project Management Institute view on the pulse of the industry and ...

  17. Space

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

    Cool Links Fascinating Fluids Household Magnets Nanoscience Pi Day Rocks Favorite Science Questions Space Squishy Circuits Sweet Surface Area Bradbury Science Museum 1350 Central ...

  18. Monte Carlo studies of medium-size telescope designs for the Cherenkov Telescope Array

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

    Wood, M. D.; Jogler, T.; Dumm, J.; Funk, S.

    2015-06-07

    In this paper, we present studies for optimizing the next generation of ground-based imaging atmospheric Cherenkov telescopes (IACTs). Results focus on mid-sized telescopes (MSTs) for CTA, detecting very high energy gamma rays in the energy range from a few hundred GeV to a few tens of TeV. We describe a novel, flexible detector Monte Carlo package, FAST (FAst Simulation for imaging air cherenkov Telescopes), that we use to simulate different array and telescope designs. The simulation is somewhat simplified to allow for efficient exploration over a large telescope design parameter space. We investigate a wide range of telescope performance parametersmore » including optical resolution, camera pixel size, and light collection area. In order to ensure a comparison of the arrays at their maximum sensitivity, we analyze the simulations with the most sensitive techniques used in the field, such as maximum likelihood template reconstruction and boosted decision trees for background rejection. Choosing telescope design parameters representative of the proposed Davies–Cotton (DC) and Schwarzchild–Couder (SC) MST designs, we compare the performance of the arrays by examining the gamma-ray angular resolution and differential point-source sensitivity. We further investigate the array performance under a wide range of conditions, determining the impact of the number of telescopes, telescope separation, night sky background, and geomagnetic field. We find a 30–40% improvement in the gamma-ray angular resolution at all energies when comparing arrays with an equal number of SC and DC telescopes, significantly enhancing point-source sensitivity in the MST energy range. Finally, we attribute the increase in point-source sensitivity to the improved optical point-spread function and smaller pixel size of the SC telescope design.« less

  19. Thinking"" telescopes for autonomous space situational awareness...

    Office of Scientific and Technical Information (OSTI)

    Laboratory Publication Date: 2011-06-08 OSTI Identifier: 1072312 Report Number(s): LA-UR-11-03322; LA-UR-11-3322 DOE Contract Number: AC52-06NA25396 Resource Type: Conference...

  20. Telescope Adaptive Optics Code

    Energy Science and Technology Software Center (OSTI)

    2005-07-28

    The Telescope AO Code has general adaptive optics capabilities plus specialized models for three telescopes with either adaptive optics or active optics systems. It has the capability to generate either single-layer or distributed Kolmogorov turbulence phase screens using the FFT. Missing low order spatial frequencies are added using the Karhunen-Loeve expansion. The phase structure curve is extremely dose to the theoreUcal. Secondly, it has the capability to simulate an adaptive optics control systems. The defaultmore » parameters are those of the Keck II adaptive optics system. Thirdly, it has a general wave optics capability to model the science camera halo due to scintillation from atmospheric turbulence and the telescope optics. Although this capability was implemented for the Gemini telescopes, the only default parameter specific to the Gemini telescopes is the primary mirror diameter. Finally, it has a model for the LSST active optics alignment strategy. This last model is highly specific to the LSST« less

  1. Perspectives on neutrino telescopes 2009

    SciTech Connect (OSTI)

    Quigg, Chris; /Fermilab /Karlsruhe U., TTP

    2009-04-01

    Remarks at the roundtable on plans for the future at the XIII International Workshop on Neutrino Telescopes.

  2. New Whole-House Solutions Case Study: Pulte Homes and Communities of Del Webb, Las Vegas Division, NV

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Pulte's Las Vegas has been a local leader in energy efficiency since 1997 when Nat Hodgson, Vice President of Construction for the Las Vegas Division of Pulte Homes and Communities of Del Webb teamed up with the U.S. Department of Energy's Building America team lead Building Science Corporation to build pilot homes in Las Vegas. Pulte has built 100% ENERGY STAR homes in the Las Vegas valley since 1999 and builds the most ENERGY STAR-labeled homes nationwide. In January 2009, Pulte opened its

  3. HUBBLE SPACE TELESCOPE ACS IMAGING OF THE GOALS SAMPLE: QUANTITATIVE STRUCTURAL PROPERTIES OF NEARBY LUMINOUS INFRARED GALAXIES WITH L{sub IR} > 10{sup 11.4} L{sub Sun}

    SciTech Connect (OSTI)

    Kim, D.-C.; Evans, A. S.; Privon, G. C. E-mail: aevans@virginia.edu; and others

    2013-05-10

    A Hubble Space Telescope/Advanced Camera for Surveys study of the structural properties of 85 luminous and ultraluminous (L{sub IR} > 10{sup 11.4} L{sub Sun }) infrared galaxies (LIRGs and ULIRGs) in the Great Observatories All-sky LIRG Survey (GOALS) sample is presented. Two-dimensional GALFIT analysis has been performed on F814W ''I-band'' images to decompose each galaxy, as appropriate, into bulge, disk, central point-spread function (PSF) and stellar bar components. The fraction of bulge-less disk systems is observed to be higher in LIRGs (35%) than in ULIRGs (20%), with the disk+bulge systems making up the dominant fraction of both LIRGs (55%) and ULIRGs (45%). Further, bulge+disk systems are the dominant late-stage merger galaxy type and are the dominant type for LIRGs and ULIRGs at almost every stage of galaxy-galaxy nuclear separation. The mean I-band host absolute magnitude of the GOALS galaxies is -22.64 {+-} 0.62 mag (1.8{sup +1.4}{sub -0.4} L{sup *}{sub I}), and the mean bulge absolute magnitude in GOALS galaxies is about 1.1 mag fainter than the mean host magnitude. Almost all ULIRGs have bulge magnitudes at the high end (-20.6 to -23.5 mag) of the GOALS bulge magnitude range. Mass ratios in the GOALS binary systems are consistent with most of the galaxies being the result of major mergers, and an examination of the residual-to-host intensity ratios in GOALS binary systems suggests that smaller companions suffer more tidal distortion than the larger companions. We find approximately twice as many bars in GOALS disk+bulge systems (32.8%) than in pure-disk mergers (15.9%) but most of the disk+bulge systems that contain bars are disk-dominated with small bulges. The bar-to-host intensity ratio, bar half-light radius, and bar ellipticity in GOALS galaxies are similar to those found in nearby spiral galaxies. The fraction of stellar bars decreases toward later merger stages and smaller nuclear separations, indicating that bars are destroyed as the merger

  4. Space Videos

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

    Space Videos Space

  5. 2014 DOE Project Management Workshop Meeting the Challenge-Integrated...

    Office of Environmental Management (EM)

    James Webb Space Telescope: PM Lessons Applied Eric Smith, Deputy Program Director, NASA 8:45 - 9:00 9:00 - 9:45 Victor Carter-Bey (PMI) 9:45 - 10:45 Steve Meador, Acting Dir ...

  6. Wide field of view telescope

    DOE Patents [OSTI]

    Ackermann, Mark R.; McGraw, John T.; Zimmer, Peter C.

    2008-01-15

    A wide field of view telescope having two concave and two convex reflective surfaces, each with an aspheric surface contour, has a flat focal plane array. Each of the primary, secondary, tertiary, and quaternary reflective surfaces are rotationally symmetric about the optical axis. The combination of the reflective surfaces results in a wide field of view in the range of approximately 3.8.degree. to approximately 6.5.degree.. The length of the telescope along the optical axis is approximately equal to or less than the diameter of the largest of the reflective surfaces.

  7. FERMI LARGE AREA TELESCOPE SECOND SOURCE CATALOG

    SciTech Connect (OSTI)

    Nolan, P. L.; Ajello, M.; Allafort, A.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Abdo, A. A.; Ackermann, M.; Antolini, E.; Bonamente, E.; Atwood, W. B.; Belfiore, A.; Axelsson, M.; Baldini, L.; Bellazzini, R.; Ballet, J.; Bastieri, D.; Bignami, G. F. E-mail: Gino.Tosti@pg.infn.it E-mail: tburnett@u.washington.edu; and others

    2012-04-01

    We present the second catalog of high-energy {gamma}-ray sources detected by the Large Area Telescope (LAT), the primary science instrument on the Fermi Gamma-ray Space Telescope (Fermi), derived from data taken during the first 24 months of the science phase of the mission, which began on 2008 August 4. Source detection is based on the average flux over the 24 month period. The second Fermi-LAT catalog (2FGL) includes source location regions, defined in terms of elliptical fits to the 95% confidence regions and spectral fits in terms of power-law, exponentially cutoff power-law, or log-normal forms. Also included are flux measurements in five energy bands and light curves on monthly intervals for each source. Twelve sources in the catalog are modeled as spatially extended. We provide a detailed comparison of the results from this catalog with those from the first Fermi-LAT catalog (1FGL). Although the diffuse Galactic and isotropic models used in the 2FGL analysis are improved compared to the 1FGL catalog, we attach caution flags to 162 of the sources to indicate possible confusion with residual imperfections in the diffuse model. The 2FGL catalog contains 1873 sources detected and characterized in the 100 MeV to 100 GeV range of which we consider 127 as being firmly identified and 1171 as being reliably associated with counterparts of known or likely {gamma}-ray-producing source classes.

  8. Neutrino telescopes in the World

    SciTech Connect (OSTI)

    Ernenwein, J.-P.

    2007-01-12

    Neutrino astronomy has rapidly developed these last years, being the only way to get specific and reliable information about astrophysical objects still poorly understood.Currently two neutrino telescopes are operational in the World: BAIKAL, in the lake of the same name in Siberia, and AMANDA, in the ices of the South Pole. Two telescopes of the same type are under construction in the Mediterranean Sea: ANTARES and NESTOR. All these telescopes belong to a first generation, with an instrumented volume smaller or equal to 0.02 km3. Also in the Mediterranean Sea, the NEMO project is just in its stag phase, within the framework of a cubic kilometer size neutrino telescope study. Lastly, the ICECUBE detector, with a volume reaching about 1 km3, is under construction on the site of AMANDA experiment, while an extension of the BAIKAL detector toward km3 is under study. We will present here the characteristics of these experiments, as well as the results of their observations.

  9. Recent Results from the MAGIC Telescope

    SciTech Connect (OSTI)

    Bock, Rudolf K.

    2005-02-21

    Some recent results are shown, obtained during the commissioning period of the MAGIC telescope. They demonstrate that the telescope is now approaching a performance level suitable for physics observations.

  10. On orbit performance of the ALEXIS EUV telescopes

    SciTech Connect (OSTI)

    Bloch, J.; Edwards, B.; Priedhorsky, W.

    1994-08-01

    The Array of Low Energy X-ray Imaging Sensors (ALEXIS) satellite is Los Alamos` first attempt at building and flying a low cost, rapid development, technology demonstration and scientific space mission. The ALEXIS satellite contains the two experiments: the ALEXIS telescope array, (which consists of six EUV/ultrasoft x-ray telescopes utilizing multilayer mirrors, each with a 33 degree field-of-view), and a VHF ionospheric experiment called Blackbeard. A ground station located at Los Alamos exclusively controls the spacecraft. The 248 pound ALEXIS satellite was launched by a Pegasus booster into a 400 {times} 450 nautical mile, 70 degree inclination orbit on April 25, 1993. Images from a video system on the rocket indicated that ALEXIS had been severely damaged during launch with one of the 4 solar panels breaking away from its mounting. (It later turned out that the solar paddle was still attached to the spacecraft but only through cable bundles.) Attempts at communicating with the satellite were unsuccessful until a surprised ground crew received a short transmission on June 2. By mid July, ground station operators had regained full control of the satellite and began to initiate scientific operations with both the telescope array and the VHF experiment. In this paper we will discuss a preliminary analysis of the on-orbit performance of EUV telescopes on ALEXIS.

  11. The Hubble space telescope UV legacy survey of galactic globular...

    Office of Scientific and Technical Information (OSTI)

    a.cunial@studenti.unipd.it 1 ; and others + Show Author Affiliations Dipartimento di Fisica e Astronomia "Galileo Galilei," Universit di Padova, Vicolo dell'Osservatorio 3,...

  12. The Space-based Telescopes for Actionable Refinement of Ephemeris...

    Office of Scientific and Technical Information (OSTI)

    Close Cite: Bibtex Format Close 0 pages in this document matching the terms "" Search For Terms: Enter terms in the toolbar above to search the full text of this document for ...

  13. Gamma-Ray Large Area Space Telescope: Mission Overview (Conference...

    Office of Scientific and Technical Information (OSTI)

    of the still-unidentified EGRET sources, detailed study of gamma-ray diffuse emission, high-energy emission from gamma-ray bursts and transient sources, and probing dark matter. ...

  14. ULTRAVIOLET NUMBER COUNTS OF GALAXIES FROM SWIFT ULTRAVIOLET/OPTICAL TELESCOPE DEEP IMAGING OF THE CHANDRA DEEP FIELD SOUTH

    SciTech Connect (OSTI)

    Hoversten, E. A.; Gronwall, C.; Koch, T. S.; Roming, P. W. A.; Siegel, M. H.; Berk, D. E. Vanden; Breeveld, A. A.; Curran, P. A.; Still, M.

    2009-11-10

    Deep Swift UV/Optical Telescope (UVOT) imaging of the Chandra Deep Field South is used to measure galaxy number counts in three near-ultraviolet (NUV) filters (uvw2: 1928 A, uvm2: 2246 A, and uvw1: 2600 A) and the u band (3645 A). UVOT observations cover the break in the slope of the NUV number counts with greater precision than the number counts by the Hubble Space Telescope Space Telescope Imaging Spectrograph and the Galaxy Evolution Explorer, spanning a range 21 approx< m{sub AB} approx< 25. Model number counts confirm earlier investigations in favoring models with an evolving galaxy luminosity function.

  15. Optical Design for Extremely Large Telescope Adaptive Optics...

    Office of Scientific and Technical Information (OSTI)

    Large Telescope Adaptive Optics Systems Citation Details In-Document Search Title: Optical Design for Extremely Large Telescope Adaptive Optics Systems You are accessing a ...

  16. Optical Design for Extremely Large Telescope Adaptive Optics...

    Office of Scientific and Technical Information (OSTI)

    ThesisDissertation: Optical Design for Extremely Large Telescope Adaptive Optics Systems Citation Details In-Document Search Title: Optical Design for Extremely Large Telescope ...

  17. "Thinking" Telescopes: An Autonomous Robotic Ecosystem for Persistent...

    Office of Scientific and Technical Information (OSTI)

    Telescopes: An Autonomous Robotic Ecosystem for Persistent Monitoring and Real-Time Response Citation Details In-Document Search Title: "Thinking" Telescopes: An...

  18. The Nuclear Spectroscopic Telescope Array (NuSTAR) Mission (Journal...

    Office of Scientific and Technical Information (OSTI)

    The Nuclear Spectroscopic Telescope Array (NuSTAR) Mission Citation Details In-Document Search Title: The Nuclear Spectroscopic Telescope Array (NuSTAR) Mission You are...

  19. The Nuclear Spectroscopic Telescope Array (NuSTAR) Mission (Journal...

    Office of Scientific and Technical Information (OSTI)

    The Nuclear Spectroscopic Telescope Array (NuSTAR) Mission Citation Details In-Document Search Title: The Nuclear Spectroscopic Telescope Array (NuSTAR) Mission Authors: Harrison,...

  20. The Nuclear Spectroscopic Telescope Array (NuSTAR) Mission (Journal...

    Office of Scientific and Technical Information (OSTI)

    Nuclear Spectroscopic Telescope Array (NuSTAR) Mission Citation Details In-Document Search Title: The Nuclear Spectroscopic Telescope Array (NuSTAR) Mission Authors: Harrison,...

  1. The Sloan Digital Sky Survey Monitor Telescope Pipeline (Journal...

    Office of Scientific and Technical Information (OSTI)

    The Sloan Digital Sky Survey Monitor Telescope Pipeline Citation Details In-Document Search Title: The Sloan Digital Sky Survey Monitor Telescope Pipeline You are accessing a...

  2. Water telescope's first sky map shows flickering black holes

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

    Water telescope's first sky map shows flickering black holes Water telescope's first sky map shows flickering black holes The High Altitude Water Cherenkov observatory has released ...

  3. Telescopic nanotube device for hot nanolithography

    DOE Patents [OSTI]

    Popescu, Adrian; Woods, Lilia M

    2014-12-30

    A device for maintaining a constant tip-surface distance for producing nanolithography patterns on a surface using a telescopic nanotube for hot nanolithography. An outer nanotube is attached to an AFM cantilever opposite a support end. An inner nanotube is telescopically disposed within the outer nanotube. The tip of the inner nanotube is heated to a sufficiently high temperature and brought in the vicinity of the surface. Heat is transmitted to the surface for thermal imprinting. Because the inner tube moves telescopically along the outer nanotube axis, a tip-surface distance is maintained constant due to the vdW force interaction, which in turn eliminates the need of an active feedback loop.

  4. Telescoping magnetic ball bar test gage

    DOE Patents [OSTI]

    Bryan, J.B.

    1982-03-15

    A telescoping magnetic ball bar test gage for determining the accuracy of machine tools, including robots, and those measuring machines having non-disengagable servo drives which cannot be clutched out. Two gage balls are held and separated from one another by a telescoping fixture which allows them relative radial motional freedom but not relative lateral motional freedom. The telescoping fixture comprises a parallel reed flexure unit and a rigid member. One gage ball is secured by a magnetic socket knuckle assembly which fixes its center with respect to the machine being tested. The other gage ball is secured by another magnetic socket knuckle assembly which is engaged or held by the machine in such manner that the center of that ball is directed to execute a prescribed trajectory, all points of which are equidistant from the center of the fixed gage ball. As the moving ball executes its trajectory, changes in the radial distance between the centers of the two balls caused by inaccuracies in the machine are determined or measured by a linear variable differential transformer (LVDT) assembly actuated by the parallel reed flexure unit. Measurements can be quickly and easily taken for multiple trajectories about several different fixed ball locations, thereby determining the accuracy of the machine.

  5. Telescoping magnetic ball bar test gage

    DOE Patents [OSTI]

    Bryan, J.B.

    1984-03-13

    A telescoping magnetic ball bar test gage for determining the accuracy of machine tools, including robots, and those measuring machines having non-disengageable servo drives which cannot be clutched out is disclosed. Two gage balls are held and separated from one another by a telescoping fixture which allows them relative radial motional freedom but not relative lateral motional freedom. The telescoping fixture comprises a parallel reed flexure unit and a rigid member. One gage ball is secured by a magnetic socket knuckle assembly which fixes its center with respect to the machine being tested. The other gage ball is secured by another magnetic socket knuckle assembly which is engaged or held by the machine in such manner that the center of that ball is directed to execute a prescribed trajectory, all points of which are equidistant from the center of the fixed gage ball. As the moving ball executes its trajectory, changes in the radial distance between the centers of the two balls caused by inaccuracies in the machine are determined or measured by a linear variable differential transformer (LVDT) assembly actuated by the parallel reed flexure unit. Measurements can be quickly and easily taken for multiple trajectories about several different fixed ball locations, thereby determining the accuracy of the machine. 3 figs.

  6. Telescoping magnetic ball bar test gage

    DOE Patents [OSTI]

    Bryan, James B.

    1984-01-01

    A telescoping magnetic ball bar test gage for determining the accuracy of machine tools, including robots, and those measuring machines having non-disengageable servo drives which cannot be clutched out. Two gage balls (10, 12) are held and separated from one another by a telescoping fixture which allows them relative radial motional freedom but not relative lateral motional freedom. The telescoping fixture comprises a parallel reed flexure unit (14) and a rigid member (16, 18, 20, 22, 24). One gage ball (10) is secured by a magnetic socket knuckle assembly (34) which fixes its center with respect to the machine being tested. The other gage ball (12) is secured by another magnetic socket knuckle assembly (38) which is engaged or held by the machine in such manner that the center of that ball (12) is directed to execute a prescribed trajectory, all points of which are equidistant from the center of the fixed gage ball (10). As the moving ball (12) executes its trajectory, changes in the radial distance between the centers of the two balls (10, 12) caused by inaccuracies in the machine are determined or measured by a linear variable differential transformer (LVDT) assembly (50, 52, 54, 56, 58, 60) actuated by the parallel reed flexure unit (14). Measurements can be quickly and easily taken for multiple trajectories about several different fixed ball (10) locations, thereby determining the accuracy of the machine.

  7. ANTARES deep sea neutrino telescope results

    SciTech Connect (OSTI)

    Mangano, Salvatore [IFIC - Instituto de Fsica Corpuscular, Edificio Institutos de Investigatin, 46071 Valencia (Spain); Collaboration: ANTARES Collaboration

    2014-01-01

    The ANTARES experiment is currently the largest underwater neutrino telescope in the Northern Hemisphere. It is taking high quality data since 2007. Its main scientific goal is to search for high energy neutrinos that are expected from the acceleration of cosmic rays from astrophysical sources. This contribution reviews the status of the detector and presents several analyses carried out on atmospheric muons and neutrinos. For example it shows the results from the measurement of atmospheric muon neutrino spectrum and of atmospheric neutrino oscillation parameters as well as searches for neutrinos from steady cosmic point-like sources, for neutrinos from gamma ray bursts and for relativistic magnetic monopoles.

  8. The Honorable Wellington E. Webb

    Office of Legacy Management (LM)

    Program Division, : ,Office,of Eastern Area Programs: '. Office,of Environmental Restoration '. ?'Bechtold,'Denver CO ' ', R; Quillin,.State oi,Colorado ,, ,,: ' .

  9. The Anti-Coincidence Detector for the GLAST Large Area Telescope

    SciTech Connect (OSTI)

    Moiseev, A.A.; Hartman, R.C.; Ormes, J.F.; Thompson, D.J.; Amato, M.J.; Johnson, T.E.; Segal, K.N.; Sheppard, D.A.

    2007-03-23

    This paper describes the design, fabrication and testing of the Anti-Coincidence Detector (ACD) for the Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT). The ACD is LAT's first-level defense against the charged cosmic ray background that outnumbers the gamma rays by 3-5 orders of magnitude. The ACD covers the top and 4 sides of the LAT tracking detector, requiring a total active area of {approx}8.3 square meters. The ACD detector utilizes plastic scintillator tiles with wave-length shifting fiber readout. In order to suppress self-veto by shower particles at high gamma-ray energies, the ACD is segmented into 89 tiles of different sizes. The overall ACD efficiency for detection of singly charged relativistic particles entering the tracking detector from the top or sides of the LAT exceeds the required 0.9997.

  10. The University of Durham Mark 6 VHE gamma ray telescope

    SciTech Connect (OSTI)

    Chadwick, P. M.; Dickinson, M. R.; Dipper, N. A.; Holder, J.; Kendall, T. R.; McComb, T. J. L.; Orford, K. J.; Rayner, S. M.; Roberts, I. D.; Shaw, S. E.; Turver, K. E.

    1997-05-10

    The operation of the University of Durham Mark 6 atmospheric Cerenkov telescope is discussed. The telescope has been used to detect gamma rays at energies {>=}150 GeV and to achieve good discrimination between gamma ray and hadron initiated showers, using both conventional imaging and novel fluctuation measures. The telescope was commissioned in 1995 and a description of its operation is presented. Verification of the performance during observations of PSR B1706-44 is described.

  11. Water telescope's first sky map shows flickering black holes

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

    Water telescope's first sky map shows flickering black holes Water telescope's first sky map shows flickering black holes The High Altitude Water Cherenkov observatory has released its first map of the sky, including the first measurements of how often black holes flicker on and off. It has also caught pulsars, supernova remnants, and other bizarre cosmic beasts. April 24, 2016 Water telescope's first sky map shows flickering black holes Three new sources of gamma rays spotted by HAWC. Credit:

  12. Frozen Telescope Looks to Ends of the Earth for Answers

    Broader source: Energy.gov [DOE]

    Researchers built a telescope at the South Pole, drilling more than a mile into the ice to detect the mysterious high-energy neutrinos.

  13. Extreme Adaptive Optics for the Thirty Meter Telescope (Conference...

    Office of Scientific and Technical Information (OSTI)

    Title: Extreme Adaptive Optics for the Thirty Meter Telescope Direct detection of extrasolar Jovian planets is a major scientific motivation for the construction of future ...

  14. "Thinking" Telescopes: An Autonomous Robotic Ecosystem for Persistent...

    Office of Scientific and Technical Information (OSTI)

    Conference: "Thinking" Telescopes: An Autonomous Robotic Ecosystem for Persistent Monitoring and Real-Time Response Citation Details In-Document Search Title: "Thinking"...

  15. Real-time condition assessment of RAPTOR telescope systems (Journal...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Real-time condition assessment of RAPTOR telescope systems Citation Details In-Document Search ... Publication Date: 2011-09-08 OSTI Identifier: 1095860 Report ...

  16. Using a cold radiometer to measure heat loads and survey heat leaks

    SciTech Connect (OSTI)

    DiPirro, M.; Tuttle, J.; Hait, T.; Shirron, P.

    2014-01-29

    We have developed an inexpensive cold radiometer for use in thermal/vacuum chambers to measure heat loads, characterize emissivity and specularity of surfaces and to survey areas to evaluate stray heat loads. We report here the results of two such tests for the James Webb Space Telescope to measure heat loads and effective emissivities of 2 major pieces of optical ground support equipment that will be used in upcoming thermal vacuum testing of the Telescope.

  17. EXO-ZODI MODELING FOR THE LARGE BINOCULAR TELESCOPE INTERFEROMETER

    SciTech Connect (OSTI)

    Kennedy, Grant M.; Wyatt, Mark C.; Panić, Olja; Shannon, Andrew; Bailey, Vanessa; Defrère, Denis; Hinz, Philip M.; Rieke, George H.; Skemer, Andrew J.; Su, Katherine Y. L.; Bryden, Geoffrey; Mennesson, Bertrand; Morales, Farisa; Serabyn, Eugene; Danchi, William C.; Roberge, Aki; Stapelfeldt, Karl R.; Haniff, Chris; Lebreton, Jérémy; Millan-Gabet, Rafael; and others

    2015-02-01

    Habitable zone dust levels are a key unknown that must be understood to ensure the success of future space missions to image Earth analogs around nearby stars. Current detection limits are several orders of magnitude above the level of the solar system's zodiacal cloud, so characterization of the brightness distribution of exo-zodi down to much fainter levels is needed. To this end, the Large Binocular Telescope Interferometer (LBTI) will detect thermal emission from habitable zone exo-zodi a few times brighter than solar system levels. Here we present a modeling framework for interpreting LBTI observations, which yields dust levels from detections and upper limits that are then converted into predictions and upper limits for the scattered light surface brightness. We apply this model to the HOSTS survey sample of nearby stars; assuming a null depth uncertainty of 10{sup –4} the LBTI will be sensitive to dust a few times above the solar system level around Sun-like stars, and to even lower dust levels for more massive stars.

  18. Representations and image classification methods for Cherenkov telescopes

    SciTech Connect (OSTI)

    Malagon, C.; Parcerisa, D. S.; Barrio, J. A.; Nieto, D.

    2008-05-29

    The problem of identifying gamma ray events out of charged cosmic ray background (so called hadrons) in Cherenkov telescopes is one of the key problems in VHE gamma ray astronomy. In this contribution, we present a novel approach to this problem by implementing different classifiers relying on the information of each pixel of the camera of a Cherenkov telescope.

  19. Fermi Large Area Telescope Measurements of the Diffuse Gamma-Ray Emission at Intermediate Galactic Latitudes

    SciTech Connect (OSTI)

    Abdo, A.A.; Ackermann, M.; Ajello, M.; Anderson, B.; Atwood, W.B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B.M.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R.D.; Bloom, E.D.; Bonamente, E.; Borgland, A.W.; Bregeon, J.; Brez, A.; Brigida, M.; /more authors..

    2012-04-11

    The diffuse galactic {gamma}-ray emission is produced by cosmic rays (CRs) interacting with the interstellar gas and radiation field. Measurements by the Energetic Gamma-Ray Experiment Telescope (EGRET) instrument on the Compton Gamma-Ray Observatory indicated excess {gamma}-ray emission {ge}1 GeV relative to diffuse galactic {gamma}-ray emission models consistent with directly measured CR spectra (the so-called 'EGRET GeV excess'). The Large Area Telescope (LAT) instrument on the Fermi Gamma-Ray Space Telescope has measured the diffuse {gamma}-ray emission with improved sensitivity and resolution compared to EGRET. We report on LAT measurements for energies 100 MeV to 10 GeV and galactic latitudes 10{sup o} {le} |b| {le} 20{sup o}. The LAT spectrum for this region of the sky is well reproduced by a diffuse galactic {gamma}-ray emission model that is consistent with local CR spectra and inconsistent with the EGRET GeV excess.

  20. In-Flight Measurement of the Absolute Energy Scale of the Fermi Large Area Telescope

    SciTech Connect (OSTI)

    Ackermann, M.; Ajello, M.; Allafort, A.; Atwood, W.B.; Axelsson, M.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bloom, E.D.; Bonamente, E.; Borgland, A.W.; Bouvier, A.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; /more authors..

    2012-09-20

    The Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope is a pair-conversion telescope designed to survey the gamma-ray sky from 20 MeV to several hundreds of GeV. In this energy band there are no astronomical sources with sufficiently well known and sharp spectral features to allow an absolute calibration of the LAT energy scale. However, the geomagnetic cutoff in the cosmic ray electron-plus-positron (CRE) spectrum in low Earth orbit does provide such a spectral feature. The energy and spectral shape of this cutoff can be calculated with the aid of a numerical code tracing charged particles in the Earth's magnetic field. By comparing the cutoff value with that measured by the LAT in different geomagnetic positions, we have obtained several calibration points between {approx}6 and {approx}13 GeV with an estimated uncertainty of {approx}2%. An energy calibration with such high accuracy reduces the systematic uncertainty in LAT measurements of, for example, the spectral cutoff in the emission from gamma ray pulsars.

  1. DEEP MULTI-TELESCOPE PHOTOMETRY OF NGC 5466. I. BLUE STRAGGLERS AND BINARY SYSTEMS

    SciTech Connect (OSTI)

    Beccari, G.; Dalessandro, E.; Lanzoni, B.; Ferraro, F. R.; Miocchi, P.; Sollima, A.; Bellazzini, M.

    2013-10-10

    We present a detailed investigation of the radial distribution of blue straggler star (BSS) and binary populations in the Galactic globular cluster NGC 5466, over the entire extension of the system. We used a combination of data acquired with the Advanced Camera for Survey on board the Hubble Space Telescope, the LBC-blue mounted on the Large Binocular Telescope, and MEGACAM on the Canada-France-Hawaii Telescope. BSSs show a bimodal distribution with a mild central peak and a quite internal minimum. This feature is interpreted in terms of a relatively young dynamical age in the framework of the 'dynamical clock' concept proposed by Ferraro et al. The estimated fraction of binaries is ?6%-7% in the central region (r < 90'') and slightly lower (?5.5%) in the outskirts, at r > 200''. Quite interestingly, the comparison with the results of Milone et al. suggests that binary systems may also display a bimodal radial distribution, with the position of the minimum consistent with that of BSSs. If confirmed, this feature would give additional support to the scenario where the radial distribution of objects more massive than the average cluster stars is primarily shaped by the effect of dynamical friction. Moreover, this would also be consistent with the idea that the unperturbed evolution of primordial binaries could be the dominant BSS formation process in low-density environments.

  2. Real-time condition assessment of RAPTOR telescope systems

    SciTech Connect (OSTI)

    Stull, Chris; Taylor, Stuart; Wren, James; Farrar, Charles; Park, Gyuhae

    2010-11-30

    The RAPid Telescopes for Optical Response (RAPTOR) observatory network consists of several robotic astronomical telescopes primarily designed to search for astrophysical transients called a gamma-ray bursts (GRBs). Although intrinsically bright, GRBs are difficult to detect because of their short duration. Typically, they are first observed by satellites that then relay the coordinates of the GRB to a ground station which, in turn, distributes the coordinates over the internet so that ground based observers can perform follow-up observations. Typically the ground based observations begin after the GRB has ended and only residual emiSSion (the 'afterglow') is left. However, if the satellite relays the GRB coordinates quickly enough, a 'fast' robotic telescope on the ground may be able to catch the GRB in progress. The RAPTOR telescope system is one of only a few in the world to have accomplished this feat. In order to achieve these results, the RAPTOR telescopes must operate autonomously at a high duty-cycle and in peak operating condition. Currently the telescopes are maintained in an ad hoc manner, often in a run-to-failure mode. The RAPTOR project could benefit greatly from a structural health monitoring (SHM) system, especially as more complex units are added to the suite of telescopes. This paper will summarize preliminary results from an SHM study performed on one of the RAPTOR telescopes. Damage scenarios that are of concern and that have been previously observed are first summarized. Then a specific study of damage to the telescope drive mechanism is presented where the data acquisition system is first described. Next, damage detection algorithms are developed with LANL's new publically available software SHMTools and the results of this process are discussed in detail. The paper will conclude with a summary of future planned refinemenls of the RAPTOR SHM system.

  3. Application of an EMCCD Camera for Calibration of Hard X-Ray Telescopes

    SciTech Connect (OSTI)

    Vogel, J K; Pivovaroff, M J; Nagarkar, V V; Kudrolli, H; Madsen, K K; Koglin, J E; Christensen, F E; Brejnholt, N F

    2011-11-08

    Recent technological innovations now make it feasible to construct hard x-ray telescopes for space-based astronomical missions. Focusing optics are capable of improving the sensitivity in the energy range above 10 keV by orders of magnitude compared to previously used instruments. The last decade has seen focusing optics developed for balloon experiments and they will soon be implemented in approved space missions such as the Nuclear Spectroscopic Telescope Array (NuSTAR) and ASTRO-H. The full characterization of x-ray optics for astrophysical and solar imaging missions, including measurement of the point spread function (PSF) as well as scattering and reflectivity properties of substrate coatings, requires a very high spatial resolution, high sensitivity, photon counting and energy discriminating, large area detector. Novel back-thinned Electron Multiplying Charge-Coupled Devices (EMCCDs) are highly suitable detectors for ground-based calibrations. Their chip can be optically coupled to a microcolumnar CsI(Tl) scintillator via a fiberoptic taper. Not only does this device exhibit low noise and high spatial resolution inherent to CCDs, but the EMCCD is also able to handle high frame rates due to its controllable internal gain. Additionally, thick CsI(Tl) yields high detection efficiency for x-rays. This type of detector has already proven to be a unique device very suitable for calibrations in astrophysics: such a camera was used to support the characterization of the performance for all NuSTAR optics. Further optimization will enable similar cameras to be improved and used to calibrate x-ray telescopes for future space missions. In this paper, we discuss the advantages of using an EMCCD to calibrate hard x-ray optics. We will illustrate the promising features of this detector solution using examples of data obtained during the ground calibration of the NuSTAR telescopes performed at Columbia University during 2010/2011. Finally, we give an outlook on ongoing

  4. Fermi Large Area Telescope Observations of the Supernova Remnant...

    Office of Scientific and Technical Information (OSTI)

    Fermi Large Area Telescope Observations of the Supernova Remnant G8.7-0.1 Citation Details ... Language: English Subject: 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 72 PHYSICS ...

  5. Intelligent Sensor Tasking for Space Collision Mitigation

    SciTech Connect (OSTI)

    Olivier, S S; Pertica, A J; Henderson, J R

    2010-04-01

    Orbital collisions pose a hazard to space operations. Using a high performance computer modeling and simulation environment for space situational awareness, we explore a new paradigm for improving satellite conjunction analysis by obtaining more precise orbital information only for those objects that pose a collision risk greater than a defined threshold to a specific set of satellites during a specified time interval. In particular, we assess the improvement in the quality of the conjunction analysis that can be achieved using a distributed network of ground-based telescopes.

  6. Relay telescope for high power laser alignment system

    DOE Patents [OSTI]

    Dane, C. Brent; Hackel, Lloyd; Harris, Fritz B.

    2006-09-19

    A laser system includes an optical path having an intracavity relay telescope with a telescope focal point for imaging an output of the gain medium between an image location at or near the gain medium and an image location at or near an output coupler for the laser system. A kinematic mount is provided within a vacuum chamber, and adapted to secure beam baffles near the telescope focal point. An access port on the vacuum chamber is adapted for allowing insertion and removal of the beam baffles. A first baffle formed using an alignment pinhole aperture is used during alignment of the laser system. A second tapered baffle replaces the alignment aperture during operation and acts as a far-field baffle in which off angle beams strike the baffle a grazing angle of incidence, reducing fluence levels at the impact areas.

  7. Hubble space telescope and ground-based observations of the type...

    Office of Scientific and Technical Information (OSTI)

    ... CA 93117 (United States) Carnegie Observatories, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile) Department of Astronomy, San Diego State University, San ...

  8. PLANETARY NEBULAE DETECTED IN THE SPITZER SPACE TELESCOPE GLIMPSE 3D LEGACY SURVEY

    SciTech Connect (OSTI)

    Zhang Yong; Hsia, Chih-Hao; Kwok, Sun E-mail: xiazh@hku.hk

    2012-01-20

    We used the data from the Spitzer Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) to investigate the mid-infrared (MIR) properties of planetary nebulae (PNs) and PN candidates. In previous studies of GLIMPSE I and II data, we have shown that these MIR data are very useful in distinguishing PNs from other emission-line objects. In the present paper, we focus on the PNs in the field of the GLIMPSE 3D survey, which has a more extensive latitude coverage. We found a total of 90 Macquarie-AAO-Strasbourg (MASH) and MASH II PNs and 101 known PNs to have visible MIR counterparts in the GLIMPSE 3D survey area. The images and photometry of these PNs are presented. Combining the derived IRAC photometry at 3.6, 4.5, 5.8, and 8.0 {mu}m with the existing photometric measurements from other infrared catalogs, we are able to construct spectral energy distributions (SEDs) of these PNs. Among the most notable objects in this survey is the PN M1-41, whose GLIMPSE 3D image reveals a large bipolar structure of more than 3 arcmin in extent.

  9. A MID-INFRARED IMAGING SURVEY OF SUBMILLIMETER-SELECTED GALAXIES WITH THE SPITZER SPACE TELESCOPE

    SciTech Connect (OSTI)

    Hainline, Laura J.; Blain, A. W.; Smail, Ian; Frayer, D. T.; Chapman, S. C.; Ivison, R. J.; Alexander, D. M. E-mail: ljh@astro.umd.edu

    2009-07-10

    We present Spitzer-IRAC and MIPS mid-IR observations of a sample of 73 radio-detected submillimeter-selected galaxies (SMGs) with spectroscopic redshifts, the largest such sample published to date. From our data, we find that IRAC colors of SMGs are much more uniform as compared with rest-frame UV and optical colors, and z>1.5 SMGs tend to be redder in their mid-IR colors than both field galaxies and lower-z SMGs. However, the IRAC colors of the SMGs overlap those of field galaxies sufficiently that color-magnitude and color-color selection criteria suggested in the literature to identify SMG counterparts produce ambiguous counterparts within an 8'' radius in 20%-35% of cases. We use a rest-frame J-H versus H-K color-color diagram and a S {sub 24}/S {sub 8.0} versus S {sub 8.0}/S {sub 4.5} color-color diagram to determine that 13%-19% of our sample are likely to contain active galactic nuclei which dominate their mid-IR emission. We observe in the rest-frame JHK colors of our sample that the rest-frame near-IR emission of SMGs does not resemble that of the compact nuclear starburst observed in local ultraluminous IR galaxies and is consistent with more widely distributed star formation. We take advantage of the fact that many high-z galaxy populations selected at different wavelengths are detected by Spitzer to carry out a brief comparison of mid-IR properties of SMGs to UV-selected high-z galaxies, 24 {mu}m-selected galaxies, and high-z radio galaxies, and find that SMGs have mid-IR fluxes and colors which are consistent with being more massive and more reddened than UV-selected galaxies, while the IRAC colors of SMGs are most similar to powerful high-z radio galaxies.

  10. PLANETARY NEBULAE DETECTED IN THE SPITZER SPACE TELESCOPE GLIMPSE II LEGACY SURVEY

    SciTech Connect (OSTI)

    Zhang Yong; Sun Kwok E-mail: sunkwok@hku.h

    2009-11-20

    We report the result of a search for the infrared counterparts of 37 planetary nebulae (PNs) and PN candidates in the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire II (GLIMPSE II) survey. The photometry and images of these PNs at 3.6, 4.5, 5.8, 8.0, and 24 mum, taken through the Infrared Array Camera (IRAC) and the Multiband Imaging Photometer for Spitzer (MIPS), are presented. Most of these nebulae are very red and compact in the IRAC bands, and are found to be bright and extended in the 24 mum band. The infrared morphology of these objects are compared with Halpha images of the Macquarie-AAO-Strasbourg (MASH) and MASH II PNs. The implications for morphological difference in different wavelengths are discussed. The IRAC data allow us to differentiate between PNs and H II regions and be able to reject non-PNs from the optical catalog (e.g., PNG 352.1 - 00.0). Spectral energy distributions are constructed by combing the IRAC and MIPS data with existing near-, mid-, and far-IR photometry measurements. The anomalous colors of some objects allow us to infer the presence of aromatic emission bands. These multi-wavelength data provide useful insights into the nature of different nebular components contributing to the infrared emission of PNs.

  11. COLLISIONALLY EXCITED FILAMENTS IN HUBBLE SPACE TELESCOPE H? AND H? IMAGES OF HH 1/2

    SciTech Connect (OSTI)

    Raga, A. C.; Castellanos-Ramrez, A.; Reipurth, B.; Chiang, Hsin-Fang; Bally, J.

    2015-01-01

    We present new H? and H? images of the HH 1/2 system, and we find that the H?/H? ratio has high values in ridges along the leading edges of the HH 1 bow shock and of the brighter condensations of HH 2. These ridges have H?/H? = 4 ? 6, which is consistent with collisional excitation from the n = 1 to the n = 3 and 4 levels of hydrogen in a gas of temperatures T = 1.5 ? 10 10{sup 4} K. This is therefore the first direct evidence that the collisional excitation/ionization region of hydrogen just behind Herbig-Haro shock fronts is detected.

  12. Fermi Gamma-Ray Space Telescope: High-Energy Results From the...

    Office of Scientific and Technical Information (OSTI)

    From the First Year Citation Details In-Document ... Report Number(s): SLAC-PUB-15630 arXiv:1011.0213 DOE Contract Number: AC02-76SF00515 Resource Type: Journal Article ...

  13. Fermi Gamma-Ray Space Telescope: High-Energy Results From the...

    Office of Scientific and Technical Information (OSTI)

    Close Cite: Bibtex Format Close 0 pages in this document matching the terms "" Search For Terms: Enter terms in the toolbar above to search the full text of this document for ...

  14. Dark matter signals at neutrino telescopes in effective theories

    SciTech Connect (OSTI)

    Catena, Riccardo

    2015-04-29

    We constrain the effective theory of one-body dark matter-nucleon interactions using neutrino telescope observations. We derive exclusion limits on the 28 coupling constants of the theory, exploring interaction operators previously considered in dark matter direct detection only, and using new nuclear response functions recently derived through nuclear structure calculations. We determine for what interactions neutrino telescopes are superior to current direct detection experiments, and show that Hydrogen is not the most important element in the exclusion limit calculation for the majority of the spin-dependent operators.

  15. Constraints on Extragalactic Background Light from Cherenkov telescopes: status and perspectives for the next 5 years

    SciTech Connect (OSTI)

    Mazin, Daniel

    2009-04-08

    Very high energy (VHE, E>30 GeV){gamma}-rays are absorbed via interaction with low-energy photons from the extragalactic background light (EBL) if the involved photon energies are above the threshold for electron-positron pair creation. The VHE {gamma}-ray absorption, which is energy dependent and increases strongly with redshift, distorts the VHE energy spectra observed from distant objects. The observed energy spectra of the AGNs carry therefore an imprint of the EBL. Recent detections of hard spectra of distant blazars (z = 0.11-0.54) by H.E.S.S. and MAGIC put strong constraints on the EBL density in the optical to near infrared waveband. It is, however, not yet possible to distinguish between an intrinsic softening of blazar spectra and a softening caused by the interaction with low energy EBL photons. In this paper, we give an overview of the EBL constraints, their limitations and perspectives for the joint efforts of the Fermi Gamma-Ray Space telescope and imaging atmospheric Cherenkov telescopes.

  16. Fermi large area telescope observations of blazar 3C 279 occultations by the sun

    SciTech Connect (OSTI)

    Barbiellini, G.; Bastieri, D.; Buson, S.; Bechtol, K.; Blandford, R. D.; Borgland, A. W.; Buehler, R.; Cameron, R. A.; Chiang, J.; Bellazzini, R.; Bregeon, J.; Bruel, P.; Caraveo, P. A.; Cavazzuti, E.; Ciprini, S.; Cecchi, C.; Chaves, R. C. G.; Cheung, C. C. E-mail: phdmitry@stanford.edu; and others

    2014-04-01

    Observations of occultations of bright ?-ray sources by the Sun may reveal predicted pair halos around blazars and/or new physics, such as, e.g., hypothetical light dark matter particlesaxions. We use Fermi Gamma-Ray Space Telescope (Fermi) data to analyze four occultations of blazar 3C 279 by the Sun on October 8 each year from 2008 to 2011. A combined analysis of the observations of these occultations allows a point-like source at the position of 3C 279 to be detected with significance of ?3?, but does not reveal any significant excess over the flux expected from the quiescent Sun. The likelihood ratio test rules out complete transparency of the Sun to the blazar ?-ray emission at a 3? confidence level.

  17. CCD AND PIN-CMOS DEVELOPMENTS FOR LARGE OPTICAL TELESCOPE.

    SciTech Connect (OSTI)

    RADEKA, V.

    2006-04-03

    Higher quantum efficiency in near-IR, narrower point spread function and higher readout speed than with conventional sensors have been receiving increased emphasis in the development of CCDs and silicon PIN-CMOS sensors for use in large optical telescopes. Some key aspects in the development of such devices are reviewed.

  18. Concept for lightweight spaced-based deposition technology

    SciTech Connect (OSTI)

    Fulton, Michael; Anders, Andre

    2006-02-28

    In this contribution we will describe a technology path to very high quality coatings fabricated in the vacuum of space. To accomplish the ambitious goals set out in NASA's Lunar-Mars proposal, advanced thin-film deposition technology will be required. The ability to deposit thin-film coatings in the vacuum of lunar-space could be extremely valuable for executing this new space mission. Developing lightweight space-based deposition technology (goal:<300 g, including power supply) will enable the future fabrication and repair of flexible large-area space antennae and fixed telescope mirrors for lunar-station observatories. Filtered Cathodic Arc (FCA) is a proven terrestrial energetic thin-film deposition technology that does not need any processing gas but is well suited for ultra-high vacuum operation. Recently, miniaturized cathodic arcs have already been developed and considered for space propulsion. It is proposed to combine miniaturized pulsed FCA technology and robotics to create a robust, enabling space-based deposition system for the fabrication, improvement, and repair of thin films, especially of silver and aluminum, on telescope mirrors and eventually on large area flexible substrates. Using miniature power supplies with inductive storage, the typical low-voltage supply systems used in space are adequate. It is shown that high-value, small area coatings are within the reach of existing technology, while medium and large area coatings are challenging in terms of lightweight technology and economics.

  19. THE NUCLEAR SPECTROSCOPIC TELESCOPE ARRAY (NuSTAR) HIGH-ENERGY...

    Office of Scientific and Technical Information (OSTI)

    NUCLEAR SPECTROSCOPIC TELESCOPE ARRAY (NuSTAR) HIGH-ENERGY X-RAY MISSION Citation Details In-Document Search Title: THE NUCLEAR SPECTROSCOPIC TELESCOPE ARRAY (NuSTAR) HIGH-ENERGY...

  20. The pixel tracking telescope at the Fermilab Test Beam Facility

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

    Kwan, Simon; Lei, CM; Menasce, Dario; Moroni, Luigi; Ngadiuba, Jennifer; Prosser, Alan; Rivera, Ryan; Terzo, Stefano; Turqueti, Marcos; Uplegger, Lorenzo; et al

    2016-03-01

    An all silicon pixel telescope has been assembled and used at the Fermilab Test Beam Facility (FTBF) since 2009 to provide precise tracking information for different test beam experiments with a wide range of Detectors Under Test (DUTs) requiring high resolution measurement of the track impact point. The telescope is based on CMS pixel modules left over from the CMS forward pixel production. Eight planes are arranged to achieve a resolution of less than 8 μm on the 120 GeV proton beam transverse coordinate at the DUT position. In order to achieve such resolution with 100 × 150 μm2 pixelmore » cells, the planes were tilted to 25 degrees to maximize charge sharing between pixels. Crucial for obtaining this performance is the alignment software, called Monicelli, specifically designed and optimized for this system. This paper will describe the telescope hardware, the data acquisition system and the alignment software constituting this particle tracking system for test beam users.« less

  1. All-sky interferometry with spherical harmonic transit telescopes

    SciTech Connect (OSTI)

    Shaw, J. Richard; Pen, Ue-Li; Sigurdson, Kris; Sitwell, Michael; Stebbins, Albert

    2014-02-01

    In this paper, we describe the spherical harmonic transit telescope through the use of a novel formalism for the analysis of transit radio telescopes. This all-sky approach bypasses the curved-sky complications of traditional interferometry and so is particularly well-suited to the analysis of wide-field radio interferometers. It enables compact and computationally efficient representations of the data and its statistics, which allow new ways of approaching important problems like map-making and foreground removal. In particular, we show how it enables the use of the Karhunen-Loève transform as a highly effective foreground filter, suppressing realistic foreground residuals for our fiducial example by at least a factor 20 below the 21 cm signal, even in highly contaminated regions of the sky. This is despite the presence of the mode-mixing inherent in real-world instruments with frequency-dependent beams. We show, using Fisher forecasting, that foreground cleaning has little effect on power spectrum constraints compared to hypothetical foreground-free measurements. Beyond providing a natural real-world data analysis framework for 21 cm telescopes now under construction and future experiments, this formalism allows accurate power spectrum forecasts to be made that include the interplay of design constraints and realistic experimental systematics with 21st century 21 cm science.

  2. Laser metrology for coherent multi-telescope arrays

    DOE Patents [OSTI]

    Shao, Michael; Massie, Norbert A.

    1993-01-01

    In multi-telescope arrays that comprise multiple telescopes, a beam-combining module, and flat mirrors for directing light beams from the multiple telescopes to the beam combining module, a laser metrology system is used for monitoring various pathlengths along a beam path where deviations are likely. Some pathlengths are defined simply by a pair of retroreflectors or reflectors at both ends. Lengths between pairs of retroreflectors are measured and monitored by laser interferometers. One critical pathlength deviation is related to the displacement of the flat mirror. A reference frame is set up relative to the beam-combining module to form and define the coordinate system within which the positions of the flat mirrors are measured and monitored. In the preferred embodiment, a pair of retroreflectors along the optical axis of the beam-combining module defines a reference frame. A triangle is formed by the reference frame as the base and another retroreflector at the flat mirror as the vertex. The triangle is used to monitor the position of the flat mirror. A beam's pathlength is dynamically corrected in response to the monitored deviations.

  3. Laser metrology for coherent multi-telescope arrays

    DOE Patents [OSTI]

    Shao, M.; Massie, N.A.

    1993-05-04

    In multi-telescope arrays that comprise multiple telescopes, a beam-combining module, and flat mirrors for directing light beams from the multiple telescopes to the beam combining module, a laser metrology system is used for monitoring various pathlengths along a beam path where deviations are likely. Some pathlengths are defined simply by a pair of retroreflectors or reflectors at both ends. Lengths between pairs of retroreflectors are measured and monitored by laser interferometers. One critical pathlength deviation is related to the displacement of the flat mirror. A reference frame is set up relative to the beam-combining module to form and define the coordinate system within which the positions of the flat mirrors are measured and monitored. In the preferred embodiment, a pair of retroreflectors along the optical axis of the beam-combining module defines a reference frame. A triangle is formed by the reference frame as the base and another retroreflector at the flat mirror as the vertex. The triangle is used to monitor the position of the flat mirror. A beam's pathlength is dynamically corrected in response to the monitored deviations.

  4. Status of the H.E.S.S. telescope

    SciTech Connect (OSTI)

    Ona Wilhelmi, E. de

    2009-04-08

    Over the past few years, very-high-energy gamma-ray astronomy has emerged as a truly observational discipline, with many detected sources representing different galactic and extragalactic source populations -supernova remnants, pulsar wind nebulae, giant molecular clouds, star formation regions, compact binary systems and active galactic nuclei. The H.E.S.S. array of imaging atmospheric Cherenkov telescopes has revealed a sky full of sources of very high energy {gamma}-rays, challenging our knowledge of particle acceleration (either hadronic or leptonic) and propagation in environments with extreme conditions. We will review the latest results published and discus the most interesting cases.

  5. A Proton Recoil Telescope Detector for Neutron Spectroscopy

    SciTech Connect (OSTI)

    Bocci, F.; Cinausero, M.; Rizzi, V.; Barbui, M.; Prete, G.; Andrighetto, A.; Lunardon, M.; Pesente, S.; Fontana, A.; Gemignian, G.; Bonomi, G.; Donzella, A.; Zenoni, A.; Fabris, D.; Morando, M.; Moretto, S.; Nebbia, G.; Viesti, G.

    2007-10-26

    A compact and versatile Proton Recoil Telescope (PRT) detector has been realized to measure neutron energy spectra in the range from few to hundred MeV. The PRT is a position sensitive detector made by: an active multilayer segmented plastic scintillator as neutron to proton converter, two silicon strip detectors for proton energy and position measurement and a final thick CsI(T1) scintillator to measure the residual proton energy. The detector has been tested with the {sup 13}C(d,n) reaction at Laboratori Nazionali del Sud using a 40 MeV deuteron beam.

  6. Pulte/Del Webb | Open Energy Information

    Open Energy Info (EERE)

    About Partnership with NREL Partnership with NREL Yes Partnership Type Test & Evaluation Partner Partnering Center within NREL Electricity Resources & Building Systems...

  7. The Nuclear Spectroscopic Telescope Array (NuSTAR) Mission Harrison...

    Office of Scientific and Technical Information (OSTI)

    (SLAC) US DOE Office of Science (DOE SC);National Aeronautics and Space Administration (NASA) United States 2014-11-20 English Journal Article Journal Name: Astrophysical Journal...

  8. Deployable telescope having a thin-film mirror and metering structure

    DOE Patents [OSTI]

    Krumel, Leslie J.; Martin, Jeffrey W.

    2010-08-24

    A deployable thin-film mirror telescope comprises a base structure and a metering structure. The base structure houses a thin-film mirror, which can be rolled for stowage and unrolled for deployment. The metering structure is coupled to the base structure and can be folded for stowage and unfolded for deployment. In the deployed state, the unrolled thin-film mirror forms a primary minor for the telescope and the unfolded metering structure positions a secondary minor for the telescope.

  9. Monte Carlo Bayesian search for the plausible source of the Telescope...

    Office of Scientific and Technical Information (OSTI)

    Title: Monte Carlo Bayesian search for the plausible source of the Telescope Array hotspot Authors: He, Hao-Ning ; Kusenko, Alexander ; Nagataki, Shigehiro ; Zhang, Bin-Bin ; Yang, ...

  10. Space Solar Power Program

    SciTech Connect (OSTI)

    Arif, H.; Barbosa, H.; Bardet, C.; Baroud, M.; Behar, A.; Berrier, K.; Berthe, P.; Bertrand, R.; Bibyk, I.; Bisson, J.; Bloch, L.; Bobadilla, G.; Bourque, D.; Bush, L.; Carandang, R.; Chiku, T.; Crosby, N.; De Seixas, M.; De Vries, J.; Doll, S.; Dufour, F.; Eckart, P.; Fahey, M.; Fenot, F.; Foeckersperger, S.; Fontaine, J.E.; Fowler, R.; Frey, H.; Fujio, H.; Gasa, J.M.; Gleave, J.; Godoe, J.; Green, I.; Haeberli, R.; Hanada, T.; Ha

    1992-08-01

    Information pertaining to the Space Solar Power Program is presented on energy analysis; markets; overall development plan; organizational plan; environmental and safety issues; power systems; space transportation; space manufacturing, construction, operations; design examples; and finance.

  11. 50 Years of Space

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

    50 Years of Space science-innovationassetsimagesicon-science.jpg 50 Years of Space Since 1943, some of the world's smartest and most dedicated technical people have ...

  12. The Atacama Cosmology Telescope: cross correlation with Planck maps

    SciTech Connect (OSTI)

    Louis, Thibaut; Calabrese, Erminia; Dunkley, Joanna; Næss, Sigurd; Addison, Graeme E.; Hincks, Adam D.; Hasselfield, Matthew; Hlozek, Renée; Bond, J. Richard; Hajian, Amir; Das, Sudeep; Devlin, Mark J.; Dünner, Rolando; Infante, Leopoldo; Gralla, Megan; Marriage, Tobias A.; Huffenberger, Kevin; Kosowsky, Arthur; Moodley, Kavilan; Niemack, Michael D.; and others

    2014-07-01

    We present the temperature power spectrum of the Cosmic Microwave Background obtained by cross-correlating maps from the Atacama Cosmology Telescope (ACT) at 148 and 218 GHz with maps from the Planck satellite at 143 and 217 GHz, in two overlapping regions covering 592 square degrees. We find excellent agreement between the two datasets at both frequencies, quantified using the variance of the residuals between the ACT power spectra and the ACT × Planck cross-spectra. We use these cross-correlations to measure the calibration of the ACT data at 148 and 218 GHz relative to Planck, to 0.7% and 2% precision respectively. We find no evidence for anisotropy in the calibration parameter. We compare the Planck 353 GHz power spectrum with the measured amplitudes of dust and cosmic infrared background (CIB) of ACT data at 148 and 218 GHz. We also compare planet and point source measurements from the two experiments.

  13. Sensitivity projections for dark matter dearches with the Fermi large area telescope

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

    Charles, E.; M. Sanchez-Conde; Anderson, B.; Caputo, R.; Cuoco, A.; Di Mauro, M.; Drlica-Wagner, A.; Gomez-Vargas, G. A.; Meyer, M.; Tibaldo, L.; et al

    2016-05-20

    In this study, the nature of dark matter is a longstanding enigma of physics; it may consist of particles beyond the Standard Model that are still elusive to experiments. Among indirect search techniques, which look for stable products from the annihilation or decay of dark matter particles, or from axions coupling to high-energy photons, observations of themore » $$\\gamma$$-ray sky have come to prominence over the last few years, because of the excellent sensitivity of the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope mission. The LAT energy range from 20 MeV to above 300 GeV is particularly well suited for searching for products of the interactions of dark matter particles. In this report we describe methods used to search for evidence of dark matter with the LAT, and review the status of searches performed with up to six years of LAT data. We also discuss the factors that determine the sensitivities of these searches, including the magnitudes of the signals and the relevant backgrounds, considering both statistical and systematic uncertainties. We project the expected sensitivities of each search method for 10 and 15 years of LAT data taking. In particular, we find that the sensitivity of searches targeting dwarf galaxies, which provide the best limits currently, will improve faster than the square root of observing time. Current LAT limits for dwarf galaxies using six years of data reach the thermal relic level for masses up to 120 GeV for the $$b\\bar{b}$$ annihilation channel for reasonable dark matter density profiles. With projected discoveries of additional dwarfs, these limits could extend to about 250 GeV. With as much as 15 years of LAT data these searches would be sensitive to dark matter annihilations at the thermal relic cross section for masses to greater than 400 GeV (200 GeV) in the $$b\\bar{b}$$ ($$\\tau^+ \\tau^-$$) annihilation channels.« less

  14. Searching for dwarf spheroidal galaxies and other galactic dark matter substructures with the Fermi large area telescope

    SciTech Connect (OSTI)

    Drlica-Wagner, Alex

    2013-08-01

    Over the past century, it has become clear that about a quarter of the known universe is composed of an invisible, massive component termed ''dark matter''. Some of the most popular theories of physics beyond the Standard Model suggest that dark matter may be a new fundamental particle that could self-annihilate to produce γ rays. Nearby over-densities in the dark matter halo of our Milky Way present some of the most promising targets for detecting the annihilation of dark matter. We used the Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope to search for γ rays produced by dark matter annihilation in Galactic dark matter substructures. We searched for γ-ray emission coincident with Milky Way dwarf spheroidal satellite galaxies, which trace the most massive Galactic dark matter substructures. We also sought to identify nearby dark matter substructures that lack all astrophysical tracers and would be detectable only through γ-ray emission from dark matter annihilation. We found no conclusive evidence for γ-ray emission from dark matter annihilation, and we set stringent and robust constraints on the dark matter annihilation cross section. While γ-ray searches for dark matter substructure are currently the most sensitive and robust probes of dark matter annihilation, they are just beginning to intersect the theoretically preferred region of dark matter parameter space. Thus, we consider future prospects for increasing the sensitivity of γ-ray searches through improvements to the LAT instrument performance and through upcoming wide- field optical surveys.

  15. CMS Pixel Telescope Addition to T-980 Bent Crystal Collimation Experiment at the Tevatron

    SciTech Connect (OSTI)

    Rivera, Ryan; Annala, Jerry; Johnson, Todd; Kwan, Simon; Lundberg, Carl; Still, Dean; Prosser, Alan; Uplegger, Lorenzo; Zagel, Jim; Zvodaya, Viktoriya; /Fermilab

    2011-09-14

    An enhancement to the T-980 bent crystal collimation experiment at the Tevatron has been completed. The enhancement was the installation of a pixel telescope inside the vacuum-sealed beam pipe of the Tevatron. The telescope is comprised of six CMS PSI46 pixel plaquettes, arranged as three stations of horizontal and vertical planes, with the CAPTAN system for data acquisition and control. The purpose of the pixel telescope is to measure beam profiles produced by bent crystals under various conditions. The telescope electronics inside the beam pipe initially were not adequately shielded from the image current of the passing beams. A new shielding approach was devised and installed, which resolved the problem. The noise issues encountered and the mitigating techniques are presented herein, as well as some preliminary results from the telescope.

  16. Space and Sensors

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

    Space and Sensors Space and Sensors Create, deliver, support, and exploit innovative sensing systems for space-based, airborne and ground-based applications to address critical national security and scientific challenges. Contact thumbnail of Business Development Executive Michael Erickson Business Development Executive Richard P. Feynman Center for Innovation (505) 667-8087 Email Space Create, deliver, support, and exploit innovative sensing systems for space-based, airborne and ground-based

  17. Detection of a New Light Boson by Cherenkov Telescopes?

    SciTech Connect (OSTI)

    Roncadelli, Marco; De Angelis, Alessandro; Mansutti, Oriana; Persic, Massimo

    2009-04-08

    Recent observations by Imaging Atmospheric Cherenkov Telescopes (IACTs) strongly suggest a transparency of the Universe to very-high-energy (VHE) photons larger than expected from current models of the Extragalactic Background Light. It has been shown that such transparency can be naturally explained by the DARMA scenario. Its basic ingredient is a very light Axion-Like Particle (ALP) predicted by many extensions of the Standard Model of elementary particles and allows for the occurrence of photon-ALP oscillations in cosmic magnetic fields. We discuss the implications of the DARMA scenario for the VHE gamma-ray spectra of blazars by contemplating all such blazars at once, which allows us to correlate the emitted {gamma}{sub em} and observed {gamma}{sub obs} spectral indexes. We show that the predicted observed spectral index {gamma}{sub obs}{sup DARMA} actually fits observations even starting from the same nominal value {gamma}{sub em}{approx_equal}2.4 for all VHE blazars. Moreover, {gamma}{sub obs}{sup DARMA} becomes independent of redshift for far-away sources. Our prediction can be tested with the satellite-borne Fermi/LAT detector as well as with the ground-based IACTs H.E.S.S., MAGIC, CANGAROO III, VERITAS and the Extensive Air Shower arrays ARGO-YBJ and MILAGRO. Our result also offers an important observational test for models of dark energy wherein quintessence is coupled to the photon through an effective dimension-five operator.

  18. THE INFRARED TELESCOPE FACILITY (IRTF) SPECTRAL LIBRARY: COOL STARS

    SciTech Connect (OSTI)

    Rayner, John T.; Cushing, Michael C.; Vacca, William D. E-mail: michael.cushing@gmail.com

    2009-12-01

    We present a 0.8-5 {mu}m spectral library of 210 cool stars observed at a resolving power of R {identical_to} {lambda}/{delta}{lambda} {approx} 2000 with the medium-resolution infrared spectrograph, SpeX, at the 3.0 m NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii. The stars have well-established MK spectral classifications and are mostly restricted to near-solar metallicities. The sample not only contains the F, G, K, and M spectral types with luminosity classes between I and V, but also includes some AGB, carbon, and S stars. In contrast to some other spectral libraries, the continuum shape of the spectra is measured and preserved in the data reduction process. The spectra are absolutely flux calibrated using the Two Micron All Sky Survey photometry. Potential uses of the library include studying the physics of cool stars, classifying and studying embedded young clusters and optically obscured regions of the Galaxy, evolutionary population synthesis to study unresolved stellar populations in optically obscured regions of galaxies and synthetic photometry. The library is available in digital form from the IRTF Web site.

  19. Hunting space rocks

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

    Hunting space rocks Hunting space rocks Nina Lanza is studying the solar system by spending six weeks on an ice sheet in Antarctica. The 36-year-old staff scientist at the Los ...

  20. Space Science and Applications

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

    the first measurements of Earth's space radiation environment and the discovery of gamma-ray bursts. The majority of ISR-1 staff hold PhDs in Space Physics, Nuclear Physics, or...

  1. Constraints on dark matter annihilation in clusters of galaxies with the Fermi large area telescope

    SciTech Connect (OSTI)

    Ackermann, M.; Ajello, M.; Allafort, A.; Bechtol, K.; Blandford, R.D.; Bloom, E.D.; Borgland, A.W.; Bouvier, A.; Buehler, R.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Ballet, J.; Bastieri, D.; Buson, S.; Bonamente, E.; Brandt, T.J.; Bruel, P. E-mail: profumo@scipp.ucsc.edu [Laboratoire Leprince-Ringuet, École polytechnique, CNRS and others

    2010-05-01

    Nearby clusters and groups of galaxies are potentially bright sources of high-energy gamma-ray emission resulting from the pair-annihilation of dark matter particles. However, no significant gamma-ray emission has been detected so far from clusters in the first 11 months of observations with the Fermi Large Area Telescope. We interpret this non-detection in terms of constraints on dark matter particle properties. In particular for leptonic annihilation final states and particle masses greater than ∼ 200 GeV, gamma-ray emission from inverse Compton scattering of CMB photons is expected to dominate the dark matter annihilation signal from clusters, and our gamma-ray limits exclude large regions of the parameter space that would give a good fit to the recent anomalous Pamela and Fermi-LAT electron-positron measurements. We also present constraints on the annihilation of more standard dark matter candidates, such as the lightest neutralino of supersymmetric models. The constraints are particularly strong when including the fact that clusters are known to contain substructure at least on galaxy scales, increasing the expected gamma-ray flux by a factor of ∼ 5 over a smooth-halo assumption. We also explore the effect of uncertainties in cluster dark matter density profiles, finding a systematic uncertainty in the constraints of roughly a factor of two, but similar overall conclusions. In this work, we focus on deriving limits on dark matter models; a more general consideration of the Fermi-LAT data on clusters and clusters as gamma-ray sources is forthcoming.

  2. New space value of the solar oblateness obtained with PICARD

    SciTech Connect (OSTI)

    Irbah, Abdanour; Meftah, Mustapha; Hauchecorne, Alain; Bocquier, Maxime; Cisse, E. Momar; Djafer, Djelloul; Corbard, Thierry

    2014-04-20

    The PICARD spacecraft was launched on 2010 June 15 with the scientific objective of studying the geometry of the Sun. It is difficult to measure solar oblateness because images are affected by optical distortion. Rolling the satellite, as done in previous space missions, determines the contribution of the telescope by assuming that the geometry of the Sun is constant during the observations. The optical response of the telescope is considered to be time-invariant during the roll operations. This is not the case for PICARD because an orbital signature is clearly observed in the solar radius computed from its images. We take this effect into account and provide the new space value of solar oblateness from PICARD images recorded in the solar continuum at 535.7 nm on 2011 July 4-5. The equator-pole radius difference is 8.4 ± 0.5 mas, which corresponds to an absolute radius difference of 6.1 km. This coincides with the mean value of all solar oblateness measurements obtained during the last two decades from the ground, balloons, and space. It is also consistent with values determined from models using helioseismology data.

  3. National Aeronautical and Space Administration (NASA) Johnson Space Flight

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Center | Department of Energy Aeronautical and Space Administration (NASA) Johnson Space Flight Center National Aeronautical and Space Administration (NASA) Johnson Space Flight Center Space Shuttle Endeavour, 2002 The NASA Johnson Space Flight Center in Houston is well known for its achievements in the U.S. space program (this 2002 photo shows the Space Shuttle Endeavour on its way to the International Space Station). Overview NASA will save approximately $43 million in facility operations

  4. National Aeronautical and Space Administration (NASA) Johnson Space Flight

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Center | Department of Energy National Aeronautical and Space Administration (NASA) Johnson Space Flight Center National Aeronautical and Space Administration (NASA) Johnson Space Flight Center Space Shuttle Endeavour, 2002 The NASA Johnson Space Flight Center in Houston is well known for its achievements in the U.S. space program (this 2002 photo shows the Space Shuttle Endeavour on its way to the International Space Station). Overview NASA will save approximately $43 million in facility

  5. Photovoltaic-Concentrator Based Power Beaming For Space Elevator Application

    SciTech Connect (OSTI)

    Becker, Daniel E.; Chiang, Richard; Keys, Catherine C.; Lyjak, Andrew W.; Starch, Michael D.; Nees, John A.

    2010-05-06

    The MClimber team, at the Student Space Systems Fabrication Laboratory of the University of Michigan, has developed a prototype robotic climber for competition in the NASA sponsored Power Beaming Challenge. This paper describes the development of the system that utilizes a simple telescope to deliver an 8 kW beam to a photovoltaic panel in order to power a one kilometer climb. Its unique approach utilizes a precision GPS signal to track the panel. Fundamental systems of the project were implemented using a design strategy focusing on robustness and modularity. Development of this design and its results are presented.

  6. TANK SPACE OPTIONS REPORT

    SciTech Connect (OSTI)

    WILLIS WL; AHRENDT MR

    2009-08-11

    Since this report was originally issued in 2001, several options proposed for increasing double-shell tank (DST) storage space were implemented or are in the process of implementation. Changes to the single-shell tank (SST) waste retrieval schedule, completion of DST space saving options, and the DST space saving options in progress have delayed the projected shortfall of DST storage space from the 2007-2011 to the 2018-2025 timeframe (ORP-11242, River Protection Project System Plan). This report reevaluates options from Rev. 0 and includes evaluations of new options for alleviating projected restrictions on SST waste retrieval beginning in 2018 because of the lack of DST storage space.

  7. The Search of Axion-Like-Particles With Fermi and Cherenkov Telescopes...

    Office of Scientific and Technical Information (OSTI)

    The Search of Axion-Like-Particles With Fermi and Cherenkov Telescopes Citation Details In-Document Search Title: The Search of Axion-Like-Particles With Fermi and Cherenkov...

  8. Fermi Large Area Telescope Observation of a Gamma-Ray Source...

    Office of Scientific and Technical Information (OSTI)

    at the Position of Eta Carinae Citation Details In-Document Search Title: Fermi Large Area Telescope Observation of a Gamma-Ray Source at the Position of Eta Carinae Authors: ...

  9. Fermi Large Area Telescope Observation of a Gamma-Ray Source...

    Office of Scientific and Technical Information (OSTI)

    at the Position of Eta Carinae Citation Details In-Document Search Title: Fermi Large Area Telescope Observation of a Gamma-Ray Source at the Position of Eta Carinae You are ...

  10. South Pole Telescope helps Argonne scientists study earliest ages of the

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

    universe | Argonne National Laboratory Related Content Employee Spotlight: Clarence Chang South Pole Telescope helps Argonne scientists study earliest ages of the universe By Louise Lerner * October 28, 2013 Tweet EmailPrint For physicist Clarence Chang at the U.S. Department of Energy's (DOE) Argonne National Laboratory, looking backward in time to the earliest ages of the universe is all in a day's work. Chang helped design and operate part of the South Pole Telescope, a project that aims

  11. Performance of the EGRET astronomical gamma ray telescope

    SciTech Connect (OSTI)

    Nolan, P.L.; Hofstadter, R.; Hughes, E.B.; Lin, Y.C.; Michelson, P.F. ); Bertsch, D.L.; Fichtel, C.E.; Hartman, R.C.; Hunter, S.D.; Mattox, J.R.; Sreekumar, P.; Thompson, D.J. . Goddard Space Flight Center)

    1992-08-01

    On April 5, 1991, the Space Shuttle Atlantis carried the Compton Gamma Ray Observatory (CGRO) into orbit, deploying the satellite on April 7. This paper reports on the EGRET instrument which was activated on April 15, and the first month of operations was devoted to verification of the instrument performance. Measurements made during that month and in the subsequent sky survey phase have verified that the instrument time resolution, angular resolution, and gamma ray detection efficiency are all within nominal limits.

  12. Large Synoptic Survey Telescope: From Science Drivers to Reference Design

    SciTech Connect (OSTI)

    Ivezic, Z.; Axelrod, T.; Brandt, W.N.; Burke, D.L.; Claver, C.F.; Connolly, A.; Cook, K.H.; Gee, P.; Gilmore, D.K.; Jacoby, S.H.; Jones, R.L.; Kahn, S.M.; Kantor, J.P.; Krabbendam, V.; Lupton, R.H.; Monet, D.G.; Pinto, P.A.; Saha, A.; Schalk, T.L.; Schneider, D.P.; Strauss, Michael A.; /Washington U., Seattle, Astron. Dept. /LSST Corp. /Penn State U., Astron. Astrophys. /KIPAC, Menlo Park /NOAO, Tucson /LLNL, Livermore /UC, Davis /Princeton U., Astrophys. Sci. Dept. /Naval Observ., Flagstaff /Arizona U., Astron. Dept. - Steward Observ. /UC, Santa Cruz /Harvard U. /Johns Hopkins U. /Illinois U., Urbana

    2011-10-14

    In the history of astronomy, major advances in our understanding of the Universe have come from dramatic improvements in our ability to accurately measure astronomical quantities. Aided by rapid progress in information technology, current sky surveys are changing the way we view and study the Universe. Next-generation surveys will maintain this revolutionary progress. We focus here on the most ambitious survey currently planned in the visible band, the Large Synoptic Survey Telescope (LSST). LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: constraining dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. It will be a large, wide-field ground-based system designed to obtain multiple images covering the sky that is visible from Cerro Pachon in Northern Chile. The current baseline design, with an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg{sup 2} field of view, and a 3,200 Megapixel camera, will allow about 10,000 square degrees of sky to be covered using pairs of 15-second exposures in two photometric bands every three nights on average. The system is designed to yield high image quality, as well as superb astrometric and photometric accuracy. The survey area will include 30,000 deg{sup 2} with {delta} < +34.5{sup o}, and will be imaged multiple times in six bands, ugrizy, covering the wavelength range 320-1050 nm. About 90% of the observing time will be devoted to a deep-wide-fast survey mode which will observe a 20,000 deg{sup 2} region about 1000 times in the six bands during the anticipated 10 years of operation. These data will result in databases including 10 billion galaxies and a similar number of stars, and will serve the majority of science programs. The remaining 10% of the observing time will be allocated to special programs such as Very Deep and Very Fast time domain surveys. We describe how the

  13. Earth, Space Sciences

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

    Earth, Space Sciences Earth, Space Sciences National security depends on science and technology. The United States relies on Los Alamos National Laboratory for the best of both. No place on Earth pursues a broader array of world-class scientific endeavors. Climate, Ocean and Sea Ice Modeling (COSIM)» Earth and Environmental Sciences Division» Intelligence and Space Research» Earth Read caption + A team of scientists is working to understand how local changes in hydrology might bring about

  14. Berkeley Lab Space

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

    Space Committee Charter Articles Presentations Feedback Contact Us ANNOUNCEMENTS Feb. 13, 2014 Courtesy Salvage Pickup Factsheet To assist the community in disposing of "no longer...

  15. Total Space Heat-

    Gasoline and Diesel Fuel Update (EIA)

    Commercial Buildings Energy Consumption Survey: Energy End-Use Consumption Tables Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration...

  16. Total Space Heat-

    Gasoline and Diesel Fuel Update (EIA)

    Revised: December, 2008 Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration Office Equip- ment Com- puters Other All Buildings...

  17. Total Space Heat-

    Gasoline and Diesel Fuel Update (EIA)

    Released: September, 2008 Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration Office Equip- ment Com- puters Other All Buildings*...

  18. Strong focus space charge

    DOE Patents [OSTI]

    Booth, Rex

    1981-01-01

    Strong focus space charge lens wherein a combination of current-carrying coils and charged electrodes form crossed magnetic and electric fields to focus charged particle beams.

  19. Passive solar space heating

    SciTech Connect (OSTI)

    Balcomb, J.D.

    1980-01-01

    An overview of passive solar space heating is presented indicating trends in design, new developments, performance measures, analytical design aids, and monitored building results.

  20. Multimegawatt space power reactors

    SciTech Connect (OSTI)

    Dearien, J.A.; Whitbeck, J.F.

    1989-01-01

    In response to the need of the Strategic Defense Initiative (SDI) and long range space exploration and extra-terrestrial basing by the National Air and Space Administration (NASA), concepts for nuclear power systems in the multi-megawatt levels are being designed and evaluated. The requirements for these power systems are being driven primarily by the need to minimize weight and maximize safety and reliability. This paper will discuss the present requirements for space based advanced power systems, technological issues associated with the development of these advanced nuclear power systems, and some of the concepts proposed for generating large amounts of power in space. 31 figs.

  1. Atoms for space

    SciTech Connect (OSTI)

    Buden, D.

    1990-10-01

    Nuclear technology offers many advantages in an expanded solar system space exploration program. These cover a range of possible applications such as power for spacecraft, lunar and planetary surfaces, and electric propulsion; rocket propulsion for lunar and Mars vehicles; space radiation protection; water and sewage treatment; space mining; process heat; medical isotopes; and self-luminous systems. In addition, space offers opportunities to perform scientific research and develop systems that can solve problems here on Earth. These might include fusion and antimatter research, using the Moon as a source of helium-3 fusion fuel, and manufacturing perfect fusion targets. In addition, nuclear technologies can be used to reduce risk and costs of the Space Exploration Initiative. 1 fig.

  2. Radiation Effects In Space

    SciTech Connect (OSTI)

    Tripathi, Ram K.

    2011-06-01

    Protecting space missions from severe exposures from radiation, in general, and long duration/deep space human missions, in particular, is a critical design driver, and could be a limiting factor. The space radiation environment consists of galactic cosmic rays (GCR), solar particle events (SPE), trapped radiation, and includes ions of all the known elements over a very broad energy range. These ions penetrate spacecraft materials producing nuclear fragments and secondary particles that damage biological tissues and microelectronic devices. One is required to know how every element (and all isotopes of each element) in the periodic table interacts and fragments on every other element in the same table as a function of kinetic energy ranging over many decades. In addition, the accuracy of the input information and database, in general and nuclear data in particular, impacts radiation exposure health assessments and payload penalty. After a brief review of effects of space radiation on materials and electronics, human space missions to Mars is discussed.

  3. Monitoring objects orbiting earth using satellite-based telescopes

    DOE Patents [OSTI]

    Olivier, Scot S.; Pertica, Alexander J.; Riot, Vincent J.; De Vries, Willem H.; Bauman, Brian J.; Nikolaev, Sergei; Henderson, John R.; Phillion, Donald W.

    2015-06-30

    An ephemeris refinement system includes satellites with imaging devices in earth orbit to make observations of space-based objects ("target objects") and a ground-based controller that controls the scheduling of the satellites to make the observations of the target objects and refines orbital models of the target objects. The ground-based controller determines when the target objects of interest will be near enough to a satellite for that satellite to collect an image of the target object based on an initial orbital model for the target objects. The ground-based controller directs the schedules to be uploaded to the satellites, and the satellites make observations as scheduled and download the observations to the ground-based controller. The ground-based controller then refines the initial orbital models of the target objects based on the locations of the target objects that are derived from the observations.

  4. Low temperature high frequency coaxial pulse tube for space application

    SciTech Connect (OSTI)

    Charrier, Aurelia; Charles, Ivan; Rousset, Bernard; Duval, Jean-Marc

    2014-01-29

    The 4K stage is a critical step for space missions. The Hershel mission is using a helium bath, which is consumed day by day (after depletion, the space mission is over) while the Plank mission is equipped with one He4 Joule-Thomson cooler. Cryogenic chain without helium bath is a challenge for space missions and 4.2K Pulse-Tube working at high frequency (around 30Hz) is one option to take it up. A low temperature Pulse-Tube would be suitable for the ESA space mission EChO (Exoplanet Characterisation Observatory, expected launch in 2022), which requires around 30mW cooling power at 6K; and for the ESA space mission ATHENA (Advanced Telescope for High ENergy Astrophysics), to pre-cool the sub-kelvin cooler (few hundreds of mW at 15K). The test bench described in this paper combines a Gifford-McMahon with a coaxial Pulse-Tube. A thermal link is joining the intercept of the Pulse-Tube and the second stage of the Gifford-McMahon. This intercept is a separator between the hot and the cold regenerators of the Pulse-Tube. The work has been focused on the cold part of this cold finger. Coupled with an active phase shifter, this Pulse-Tube has been tested and optimized and temperatures as low as 6K have been obtained at 30Hz with an intercept temperature at 20K.

  5. National Aeronautical and Space Administration (NASA) Johnson...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    National Aeronautical and Space Administration (NASA) Johnson Space Flight Center National Aeronautical and Space Administration (NASA) Johnson Space Flight Center Space Shuttle ...

  6. National Aeronautical and Space Administration (NASA) Johnson...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Aeronautical and Space Administration (NASA) Johnson Space Flight Center National Aeronautical and Space Administration (NASA) Johnson Space Flight Center Space Shuttle Endeavour, ...

  7. Multiwavelength Opportunities for GeV and TeV Telescopes

    SciTech Connect (OSTI)

    Thompson, D. J.

    2009-04-08

    With AGILE and Fermi now in orbit and TeV telescopes continuing to improve their performance, a variety of multiwavelength opportunities is increasingly available. One goal of such programs is to take advantage of the complementary capabilities of the two types of telescopes: the wide field surveys of the satellite detectors and the high sensitivity and resolution of the ground-based telescopes. Some aspects of these multiwavelength efforts will be carried out in near-real-time but must be anticipated with advance preparation. These include gamma-ray burst follow-ups and flare campaigns. Other projects such as long-term variability studies and gamma-ray source identification require deep observations and cooperative work with astrophysicists at longer wavelengths, along with the theoretical studies that tie the observations together.

  8. Relay telescope including baffle, and high power laser amplifier utilizing the same

    DOE Patents [OSTI]

    Dane, C. Brent; Hackel, Lloyd; Harris, Fritz B.

    2006-09-19

    A laser system includes an optical path having an intracavity relay telescope with a telescope focal point for imaging an output of the gain medium between an image location at or near the gain medium and an image location at or near an output coupler for the laser system. A kinematic mount is provided within a vacuum chamber, and adapted to secure beam baffles near the telescope focal point. An access port on the vacuum chamber is adapted for allowing insertion and removal of the beam baffles. A first baffle formed using an alignment pinhole aperture is used during alignment of the laser system. A second tapered baffle replaces the alignment aperture during operation and acts as a far-field baffle in which off angle beams strike the baffle a grazing angle of incidence, reducing fluence levels at the impact areas.

  9. The High-Resolution Lightweight Telescope for the EUV (HiLiTE)

    SciTech Connect (OSTI)

    Martinez-Galarce, D S; Boerner, P; Soufli, R; De Pontieu, B; Katz, N; Title, A; Gullikson, E M; Robinson, J C; Baker, S L

    2008-06-02

    The High-resolution Lightweight Telescope for the EUV (HiLiTE) is a Cassegrain telescope that will be made entirely of Silicon Carbide (SiC), optical substrates and metering structure alike. Using multilayer coatings, this instrument will be tuned to operate at the 465 {angstrom} Ne VII emission line, formed in solar transition region plasma at {approx}500,000 K. HiLiTE will have an aperture of 30 cm, angular resolution of {approx}0.2 arc seconds and operate at a cadence of {approx}5 seconds or less, having a mass that is about 1/4 that of one of the 20 cm aperture telescopes on the Atmospheric Imaging Assembly (AIA) instrument aboard NASA's Solar Dynamics Observatory (SDO). This new instrument technology thus serves as a path finder to a post-AIA, Explorer-class missions.

  10. Metrology for x-ray telescope mirrors in a vertical configuration

    SciTech Connect (OSTI)

    Li, Haizhang; Li, Xiaodan; Grindel, M.W.

    1995-09-01

    Mirrors used in x-ray telescope systems for observations outside of the earth`s atmosphere are usually made of several thin nested shells, each formed by a pair of paraboloidal and hyperboloidal surfaces. The thin shells are very susceptible to self-weight deflection caused by gravity and are nearly impossible to test by conventional interferometric techniques. The metrology requirements for these mirrors are extremely challenging. This paper presents a prototype of a Vertical Scanning Long Trace Profiler (VSLTP) which is optimized to measure the surface figure of x-ray telescope mirrors in a vertical orientation. The optical system of the VSLTP is described. Experimental results from measurements on an x-ray telescope mandrel and tests of the accuracy and repeatability of the prototype VSLTP are presented. The prototype instrument has achieved a height measurement accuracy of about 50 nanometers with a repeatability of better than 20 nanometers, and a slope measurement accuracy of about 1 microradian.

  11. DC 12m telescope. Preliminary calculations. Investigation of elevation axis position.

    SciTech Connect (OSTI)

    Guarino, V. J.; High Energy Physics

    2009-12-18

    This paper examines some simple calculations of a 2D model of a telescope in order to understand how different design parameters affect the design. For the design of a telescope it is assumed that they need a design that minimizes deflections of the dish and also minimizes the size of the motors and torques needed to rotate in elevation. A common belief is that a lighter dish and minimum counterweight is desirable. However, these calculations show this is not necessarily true. The torque needed for rotation depends on the moment of inertia and if the telescope is balanced about the elevation axis. A light dish with no CW requires that the elevation axis be several meters in front of the dish (8-9m) in order to be balanced. This is not practical from a structural point of view. If the elevation axis is only 2m in front of the dish and there is no counterweight then the telescope will be unbalanced and the toruqes required will be very high - much higher than the torques needed only to overcome inertia. A heavy dish though can act as its own counterweight and the elevation axis only has to be 2-3m in front of the dish in order to achieve a balanced telescope. Also the struts that support the camera from the dish place a load on the dish which will put a bending moment on the dish. This bending moment will deform the dish and require it to be stiffer. A counterweight structure performs two functions. First, it allows the telescope to be balanced about the elevation axis. Second, it applies a force on the dish that opposes the forces from the camera struts, thereby reducing the bending moment and deformations of the dish.

  12. First search for neutrinos in correlation with gamma-ray bursts with the ANTARES neutrino telescope

    SciTech Connect (OSTI)

    NONE

    2013-03-01

    A search for neutrino-induced muons in correlation with a selection of 40 gamma-ray bursts that occurred in 2007 has been performed with the ANTARES neutrino telescope. During that period, the detector consisted of 5 detection lines. The ANTARES neutrino telescope is sensitive to TeVPeV neutrinos that are predicted from gamma-ray bursts. No events were found in correlation with the prompt photon emission of the gamma-ray bursts and upper limits have been placed on the flux and fluence of neutrinos for different models.

  13. Total Space Heat-

    Gasoline and Diesel Fuel Update (EIA)

    Survey: Energy End-Use Consumption Tables Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration Office Equip- ment Com- puters Other...

  14. Nearest Alignment Space Termination

    Energy Science and Technology Software Center (OSTI)

    2006-07-13

    Near Alignment Space Termination (NAST) is the Greengenes algorithm that matches up submitted sequences with the Greengenes database to look for similarities and align the submitted sequences based on those similarities.

  15. Space Nuclear MIssion History

    Office of Energy Efficiency and Renewable Energy (EERE)

    For over fifty years, the Department of Energy has enabled space exploration on 27 missions by providing safe reliable radioistope power systems and radioisotope heater units for NASA, Navy, Air...

  16. space booklet_DOE

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

    U C L E A R E N E R G Y DOE/NE-0071 U . S . D e p a r t m e n t o f E n e r g y O f f i c e o f N u c l e a r E n e r g y , S c i e n c e a n d T e c h n o l o g y N UCLEAR Power in Space 2 On the cover: Launch of the Atlantis Space Shuttle carrying Galileo into space (October 1989). 1 Nuclear Power in Space Table of Contents Introduction 3 Contemplating the Heavens 4 The Pioneer Missions 7 The Voyager Missions 8 The Ulysses Mission 8 The Galileo Mission 11 The Missions - An Overview 16 Power in

  17. Space Science and Applications

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

    programs sponsored by the Department of Energy (DOE), the Department of Defense (DoD), the National Aeronautics and Space Administration (NASA), and other U.S. government agencies. ...

  18. Intelligence and Space Research

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

    ISR Intelligence and Space Research Create, deliver, support, and exploit innovative sensing systems for space-based, airborne and ground-based applications to address critical national security and scientific challenges Leadership Division Leader Kevin Saeger Deputy Division Leader Angela Mielke Contacts Chief of Staff Aimee Blanchard Email Executive Office Administrator Mary T. Wubbena Email Create, deliver, support and exploit innovative sensing systems Innovative sensing systems for

  19. DETECTABILITY OF EXOPLANET PERIASTRON PASSAGE IN THE INFRARED

    SciTech Connect (OSTI)

    Kane, Stephen R.; Gelino, Dawn M.

    2011-11-01

    Characterization of exoplanets has matured in recent years, particularly through studies of exoplanetary atmospheres of transiting planets at infrared wavelengths. The primary source for such observations has been the Spitzer Space Telescope but these studies are anticipated to continue with the James Webb Space Telescope. A relatively unexplored region of exoplanet parameter space is the thermal detection of long-period eccentric planets during periastron passage. Here we describe the thermal properties and albedos of long-period giant planets along with the eccentricities of those orbits which allow them to remain within the habitable zone. We further apply these results to the known exoplanets by calculating temperatures and flux ratios for the IRAC passbands occupied by warm Spitzer, considering both low and high thermal redistribution efficiencies from the perspective of an observer. We conclude with recommendations on which targets are best suited for follow-up observations.

  20. Verification and operation of adaptive materials in space.

    SciTech Connect (OSTI)

    Dargaville, Tim Richard; Elliott, Julie M.; Jones, Gary D.; Celina, Mathias Christopher

    2006-12-01

    Piezoelectric polymers based on polyvinylidene fluoride (PVDF) are of interest as smart materials for novel space-based telescope applications. Dimensional adjustments of adaptive thin polymer films are achieved via controlled charge deposition. Predicting their long-term performance requires a detailed understanding of the piezoelectric property changes that develop during space environmental exposure. The overall materials performance is governed by a combination of chemical and physical degradation processes occurring in low Earth orbit as established by our past laboratory-based materials performance experiments (see report SAND 2005-6846). Molecular changes are primarily induced via radiative damage, and physical damage from temperature and atomic oxygen exposure is evident as depoling, loss of orientation and surface erosion. The current project extension has allowed us to design and fabricate small experimental units to be exposed to low Earth orbit environments as part of the Materials International Space Station Experiments program. The space exposure of these piezoelectric polymers will verify the observed trends and their degradation pathways, and provide feedback on using piezoelectric polymer films in space. This will be the first time that PVDF-based adaptive polymer films will be operated and exposed to combined atomic oxygen, solar UV and temperature variations in an actual space environment. The experiments are designed to be fully autonomous, involving cyclic application of excitation voltages, sensitive film position sensors and remote data logging. This mission will provide critically needed feedback on the long-term performance and degradation of such materials, and ultimately the feasibility of large adaptive and low weight optical systems utilizing these polymers in space.

  1. Space Managment | The Ames Laboratory

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

    Space Managment Space Utilization The Space Utilization report is required by DOE-CH and provides the most up-to-date information on room use by the Laboratory. The current version can be obtained from Tom Lograsso, Deputy Director.

  2. Detection of the Crab Pulsar above 25 GeV with the MAGIC Telescope

    SciTech Connect (OSTI)

    Shayduk, M

    2009-04-08

    The 17 m diameter Cherenkov telescope MAGIC, located on the Canary Island of La Palma, has the lowest trigger threshold among operating Cherenkov telescopes; this makes it a very promising tool for the detection of the pulsed gamma-ray ({gamma}-ray) emission from ground. Recently, a new analog summation trigger concept, which allows reducing the threshold even further, has been designed and implemented. The analog signals of patches in the camera, comprising 18 pixels each, are summed up in the analog mode. In order to prevent triggers from photomultiplier (PMT) afterpulses, the individual pixel signals are clipped at a preset amplitude level and then added up. The average FWHM of the time duration of signals induced by cosmic rays is 2.6 ns. This allows one to keep the coincidence time window very small and thus to strongly suppress accidental triggers. In the usual digital trigger designs, the signal should be above a certain threshold from each individual pixel to contribute to the trigger. In the summation trigger all low amplitude signals in a given patch in the camera are summed up and fully contribute to the trigger.The new trigger concept provides a low cost trigger for Cherenkov telescopes and it is very effective and stable. This trigger system for the MAGIC telescope was installed in October 2007 and was successfully used in the detection of the Crab Pulsar above 25 GeV.

  3. Multimegawatt Space Reactor Safety

    SciTech Connect (OSTI)

    Stanley, M.L. )

    1989-01-01

    The Multimegawatt (MMW) Space Reactor Project supports the Strategic Defense Initiative Office requirement to provide reliable, safe, cost-effective, electrical power in the MMW range. Specifically, power may be used for neutral particle beams, free electron lasers, electromagnetic launchers, and orbital transfer vehicles. This power plant technology may also apply to the electrical power required for other uses such as deep-space probes and planetary exploration. The Multimegawatt Space Reactor Project, the Thermionic Fuel Element Verification Program, and Centaurus Program all support the Multimegawatt Space Nuclear Power Program and form an important part of the US Department of Energy's (DOE's) space and defense power systems activities. A major objective of the MMW project is the development of a reference flight system design that provides the desired levels of public safety, health protection, and special nuclear material (SNM) protection when used during its designated missions. The safety requirements for the MMW project are a hierarchy of requirements that consist of safety requirements/regulations, a safety policy, general safety criteria, safety technical specifications, safety design specifications, and the system design. This paper describes the strategy and philosophy behind the development of the safety requirements imposed upon the MMW concept developers. The safety organization, safety policy, generic safety issues, general safety criteria, and the safety technical specifications are discussed.

  4. space exploration radioisotope power systems

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

    space exploration radioisotope power systems - Sandia Energy Energy Search Icon Sandia ... SunShot Grand Challenge: Regional Test Centers space exploration radioisotope power ...

  5. Hunting space rocks

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

    Hunting space rocks Hunting space rocks Nina Lanza is studying the solar system by spending six weeks on an ice sheet in Antarctica. The 36-year-old staff scientist at the Los Alamos National Laboratory in New Mexico is on a treasure hunt of sorts. January 15, 2016 Nina Lanza Nina Lanza is part of a team driving across the Trans-Antarctica Mountains on snowmobiles in search of meteorites. (Courtesy of Nina Lanza) "One of the most interesting things from meteorites is every rocky body has a

  6. Space Conditioning Standing Technical Commitee Presentation ...

    Energy Savers [EERE]

    Space Conditioning Standing Technical Commitee Presentation Space Conditioning Standing Technical Commitee Presentation This presentation outlines the goals of the Space ...

  7. Semantic Space Analyst

    Energy Science and Technology Software Center (OSTI)

    2004-04-15

    The Semantic Space Analyst (SSA) is software for analyzing a text corpus, discovering relationships among terms, and allowing the user to explore that information in different ways. It includes features for displaying and laying out terms and relationships visually, for generating such maps from manual queries, for discovering differences between corpora. Data can also be exported to Microsoft Excel.

  8. SPACES Sandia Offices Par

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

    a public face for Sandia National Laboratories, providing access to the Labs, and building linkages with the community. It will be a place where Sandians and their industrial, academic, and government par tners can interact easily and freely, outside the gates. Located in the Sandia Science & Technology Park (SS&TP), the new multi-tenant facility will be dedicated to increasing Sandia's collaboration and commercialization activities. C3 will offer spaces for lease along with programs and

  9. A Pair Production Telescope for Medium-Energy Gamma-Ray Polarimetry

    SciTech Connect (OSTI)

    Hunter , Stanley D.; Bloser, Peter F.; Depaola, Gerardo O.; Dion, Michael P.; DeNolfo, Georgia A.; Hanu, Andrei; Iparraguirre, Marcos; Legere, Jason; Longo, Francesco; McConnell, Mark L.; Nowicki, Suzanne F.; Ryan, James M.; Son, Seunghee; Stecker, Floyd W.

    2014-08-01

    We describe the science motivation and development of a pair production telescope for medium-13 energy gamma-ray polarimetry. Our instrument concept, the Advanced Energetic Pair Telescope 14 (AdEPT), takes advantage of the Three-Dimensional Track Imager, a low-density gaseous time 15 projection chamber, to achieve angular resolution within a factor of two of the pair production 16 kinematics limit (~0.6 at 70 MeV), continuum sensitivity comparable with the Fermi-LAT front 17 detector (<310-6 MeV cm-2 s-1 at 70 MeV), and minimum detectable polarization less than 10% 18 for a 10 millicrab source in 106 seconds.

  10. 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

  11. 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.

  12. A multipurpose TIM-based optical telescope for Omega and the Trident laser facilities

    SciTech Connect (OSTI)

    Oertel, J.A.; Murphy, T.J.; Berggren, R.R.

    1998-12-31

    The authors have recently designed and are building a telescope which acts as an imaging light collector relaying the image to an optical table for experiment dependent analysis and recording. The expected primary use of this instrument is a streaked optical pyrometer for witness plate measurements of Hohlraum drive temperature. The telescope is based on University of Rochester`s Ten-Inch Manipulator (TIM) which allows compatibility between Omega, Trident, and the NIF lasers. The optics capture a f/7 cone of light, have a field of view of 6-mm, have a spatial resolution of 5 to 7-{micro}m per line pair at the object plane, and are optimized for operation at 280-nm. The image is at a magnification of 11.7x, which is convenient for many experiments, but can be changed using additional optics that reside outside the TIM.

  13. Multipurpose 10 in. manipulator-based optical telescope for Omega and the Trident laser facilities

    SciTech Connect (OSTI)

    Oertel, J.A.; Murphy, T.J.; Berggren, R.R.; Faulkner, J.; Schmell, R.; Little, D.; Archuleta, T.; Lopez, J.; Velarde, J.; Horton, R.F.

    1999-01-01

    We have recently designed and are building a telescope which acts as an imaging light collector relaying the image to an optical table for experiment dependent analysis and recording. The expected primary use of this instrument is a streaked optical pyrometer for witness plate measurements of the hohlraum drive temperature. The telescope is based on the University of Rochester{close_quote}s 10 in. manipulator (TIM) which allows compatibility between Omega, Trident, and the NIF lasers. The optics capture a f/7 cone of light, have a field of view of 6 mm, have a spatial resolution of 5{endash}7 {mu}m per line pair at the object plane, and are optimized for operation at 280 nm. The image is at a magnification of 11.7{times}, which is convenient for many experiments, but can be changed using additional optics that reside outside the TIM. {copyright} {ital 1999 American Institute of Physics.}

  14. OSCILLATORY BEHAVIOR IN THE QUIET SUN OBSERVED WITH THE NEW SOLAR TELESCOPE

    SciTech Connect (OSTI)

    Andic, A.; Goode, P. R.; Cao, W.; Yurchyshyn, V.; Abramenko, V.; Chae, J.; Ahn, K.

    2010-07-10

    Surface photometry of the quiet Sun has achieved an angular resolution of 0.''1 with the New Solar Telescope at Big Bear Solar Observatory, revealing that a disproportionate fraction of the oscillatory events appear above observed bright point-like structures. During the tracking of these structures, we noted that the more powerful oscillatory events are cospatial with them, indicating that observed flux tubes may be the source of many observed oscillatory events.

  15. DISCOVERY OF NINE GAMMA-RAY PULSARS IN FERMI LARGE AREA TELESCOPE DATA USING A NEW BLIND SEARCH METHOD

    SciTech Connect (OSTI)

    Pletsch, H. J.; Allen, B.; Aulbert, C.; Fehrmann, H.; Guillemot, L.; Kramer, M.; Barr, E. D.; Champion, D. J.; Eatough, R. P.; Freire, P. C. C.; Ray, P. S.; Belfiore, A.; Dormody, M.; Camilo, F.; Caraveo, P. A.; Celik, Oe.; Ferrara, E. C.; Hessels, J. W. T.; Keith, M.; Kerr, M. E-mail: guillemo@mpifr-bonn.mpg.de; and others

    2012-01-10

    We report the discovery of nine previously unknown gamma-ray pulsars in a blind search of data from the Fermi Large Area Telescope (LAT). The pulsars were found with a novel hierarchical search method originally developed for detecting continuous gravitational waves from rapidly rotating neutron stars. Designed to find isolated pulsars spinning at up to kHz frequencies, the new method is computationally efficient and incorporates several advances, including a metric-based gridding of the search parameter space (frequency, frequency derivative, and sky location) and the use of photon probability weights. The nine pulsars have spin frequencies between 3 and 12 Hz, and characteristic ages ranging from 17 kyr to 3 Myr. Two of them, PSRs J1803-2149 and J2111+ 4606, are young and energetic Galactic-plane pulsars (spin-down power above 6 Multiplication-Sign 10{sup 35} erg s{sup -1} and ages below 100 kyr). The seven remaining pulsars, PSRs J0106+4855, J0622+3749, J1620-4927, J1746-3239, J2028+3332, J2030+4415, and J2139+4716, are older and less energetic; two of them are located at higher Galactic latitudes (|b| > 10 Degree-Sign ). PSR J0106+4855 has the largest characteristic age (3 Myr) and the smallest surface magnetic field (2 Multiplication-Sign 10{sup 11} G) of all LAT blind-search pulsars. PSR J2139+4716 has the lowest spin-down power (3 Multiplication-Sign 10{sup 33} erg s{sup -1}) among all non-recycled gamma-ray pulsars ever found. Despite extensive multi-frequency observations, only PSR J0106+4855 has detectable pulsations in the radio band. The other eight pulsars belong to the increasing population of radio-quiet gamma-ray pulsars.

  16. Drill string splined resilient tubular telescopic joint for balanced load drilling of deep holes

    SciTech Connect (OSTI)

    Garrett, W.R.

    1981-08-04

    A drill string splined resilient tubular telescopic joint for balanced load deep well drilling comprises a double acting damper having a very low spring rate upon both extension and contraction from the zero deflection condition. Preferably the spring means itself is a double acting compression spring means wherein the same spring means is compressed whether the joint is extended or contracted. The damper has a like low spring rate over a considerable range of deflection, both upon extension and contraction of the joint, but a gradually then rapidly increased spring rate upon approaching the travel limits in each direction. Stacks of spring rings are employed for the spring means, the rings being either shaped elastomer-metal sandwiches or, preferably, roller belleville springs. The spline and spring means are disposed in an annular chamber formed by mandrel and barrel members constituting the telescopic joint. The spring rings make only such line contact with one of the telescoping members as is required for guidance therefrom, and no contact with the other member. The chamber containing the spring means, and also containing the spline means, is filled with lubricant, the chamber being sealed with a pressure seal at its lower end and an inverted floating seal at its upper end. Magnetic and electrical means are provided to check for the presence and condition of the lubricant. To increase load capacity the spring means is made of a number of components acting in parallel.

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

    SciTech Connect (OSTI)

    Abbasi, R.U.; et al.

    2015-11-06

    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.

  18. Using star tracks to determine the absolute pointing of the Fluorescence Detector telescopes of the Pierre Auger Observatory

    SciTech Connect (OSTI)

    De Donato, Cinzia; Sanchez, Federico; Santander, Marcos; Natl.Tech.U., San Rafael; Camin, Daniel; Garcia, Beatriz; Grassi, Valerio; /Milan U. /INFN, Milan

    2005-05-01

    To accurately reconstruct a shower axis from the Fluorescence Detector data it is essential to establish with high precision the absolute pointing of the telescopes. To d that they calculate the absolute pointing of a telescope using sky background data acquired during regular data taking periods. The method is based on the knowledge of bright star's coordinates that provide a reliable and stable coordinate system. it can be used to check the absolute telescope's pointing and its long-term stability during the whole life of the project, estimated in 20 years. They have analyzed background data taken from January to October 2004 to determine the absolute pointing of the 12 telescopes installed both in Los Leones and Coihueco. The method is based on the determination of the mean-time of the variance signal left by a star traversing a PMT's photocathode which is compared with the mean-time obtained by simulating the track of that star on the same pixel.

  19. AERaSPACE CORPORATION

    Office of Legacy Management (LM)

    THE ' AERaSPACE CORPORATION Suite 300, 955 L' &njon~ Pkzza. S. W., Washingvan. D.C. 200242174, Tekphanc (202) 488~6CllO 7117-03.87.cdy.43 23 September 1987 CA CA.Ot M r. Andrew Wallo, III. NE-23 Division of Facility & Site cr.05 Decommissioning Projects FL .0-d U.S. Department of Energy TAl.OL Germantown; Maryland 20545 JA/.OZ 1hJ . o-01 Dear M r. Wallo: flA.05 ELIMINATION RECOMMENDATION -- COLLEGES AND UNIVERSITIES M /4.0-* 11 D.OF The attached elimination recommendation was prepared in

  20. County, LANL consider colocation space

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

    County, LANL consider colocation space County, LANL consider colocation space The space will be geared toward a wide range of users: entrepreneurs, freelances, young professionals, small business, visiting corporate employees, LANL staff, LANL strategic partners and youth. April 24, 2016 Y project logo The 2,400-square-foot facility at 150 Central Park Square will include a large open collaborative space, a private meeting room available for rent, a kitchen and "phone booths" for

  1. SPACE BASED INTERCEPTOR SCALING

    SciTech Connect (OSTI)

    G. CANAVAN

    2001-02-01

    Space Based Interceptor (SBI) have ranges that are adequate to address rogue ICBMs. They are not overly sensitive to 30-60 s delay times. Current technologies would support boost phase intercept with about 150 interceptors. Higher acceleration and velocity could reduce than number by about a factor of 3 at the cost of heavier and more expensive Kinetic Kill Vehicles (KKVs). 6g SBI would reduce optimal constellation costs by about 35%; 8g SBI would reduce them another 20%. Interceptor ranges fall rapidly with theater missile range. Constellations increase significantly for ranges under 3,000 km, even with advanced interceptor technology. For distributed launches, these estimates recover earlier strategic scalings, which demonstrate the improved absentee ratio for larger or multiple launch areas. Constellations increase with the number of missiles and the number of interceptors launched at each. The economic estimates above suggest that two SBI per missile with a modest midcourse underlay is appropriate. The SBI KKV technology would appear to be common for space- and surface-based boost phase systems, and could have synergisms with improved midcourse intercept and discrimination systems. While advanced technology could be helpful in reducing costs, particularly for short range theater missiles, current technology appears adequate for pressing rogue ICBM, accidental, and unauthorized launches.

  2. Constrained space camera assembly

    DOE Patents [OSTI]

    Heckendorn, Frank M.; Anderson, Erin K.; Robinson, Casandra W.; Haynes, Harriet B.

    1999-01-01

    A constrained space camera assembly which is intended to be lowered through a hole into a tank, a borehole or another cavity. The assembly includes a generally cylindrical chamber comprising a head and a body and a wiring-carrying conduit extending from the chamber. Means are included in the chamber for rotating the body about the head without breaking an airtight seal formed therebetween. The assembly may be pressurized and accompanied with a pressure sensing means for sensing if a breach has occurred in the assembly. In one embodiment, two cameras, separated from their respective lenses, are installed on a mounting apparatus disposed in the chamber. The mounting apparatus includes means allowing both longitudinal and lateral movement of the cameras. Moving the cameras longitudinally focuses the cameras, and moving the cameras laterally away from one another effectively converges the cameras so that close objects can be viewed. The assembly further includes means for moving lenses of different magnification forward of the cameras.

  3. Telescope Guiding with a HyViSI H2RG Used in Guide Mode

    SciTech Connect (OSTI)

    Simms, Lance M.; Figerb, Donald F.; Hanold, Brandon J.; Kahn, Steven M.; Gilmore, D.Kirk

    2010-06-04

    We report on long exposure results obtained with a Teledyne HyViSI H2RG detector operating in guide mode. The sensor simultaneously obtained nearly seeing-limited data while also guiding the Kitt Peak 2.1 m telescope. Results from unguided and guided operation are presented and used to place lower limits on flux/fluence values for accurate centroid measurements. We also report on significant noise reduction obtained in recent laboratory measurements that should further improve guiding capability with higher magnitude stars.

  4. OSTIblog Articles in the telescopes Topic | OSTI, US Dept of Energy Office

    Office of Scientific and Technical Information (OSTI)

    of Scientific and Technical Information telescopes Topic Observing Gamma-ray Bursts in Distant Galaxies by Kathy Chambers 21 Nov, 2013 in Science Communications 13926 Gamma-ray%20burst_caption.jpg Observing Gamma-ray Bursts in Distant Galaxies Read more about 13926 Star gazing seems especially good on a clear autumn night. From our back deck our amateur eyes scan the sky and its wonder. We first notice Venus, our closest planetary neighbor. A beautiful harvest moon rises over the hill,

  5. Indirect searches for dark matter with the Fermi large area telescope

    SciTech Connect (OSTI)

    Albert, Andrea

    2015-03-24

    There is overwhelming evidence that non-baryonic dark matter constitutes ~ 27% of the energy density of the Universe. Weakly Interacting Massive Particles (WIMPs) are promising dark matter candidates that may produce γ rays via annihilation or decay detectable by the Fermi Large Area Telescope (LAT). A detection of WIMPs would also indicate the existence of physics beyond the Standard Model. We present recent results from the two cleanest indirect WIMP searches by the Fermi-LAT Collaboration: searches for γ-ray spectral lines and γ-ray emission associated with Milky Way dwarf spheroidal satellite galaxies.

  6. Indirect searches for dark matter with the Fermi large area telescope

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

    Albert, Andrea

    2015-03-24

    There is overwhelming evidence that non-baryonic dark matter constitutes ~ 27% of the energy density of the Universe. Weakly Interacting Massive Particles (WIMPs) are promising dark matter candidates that may produce γ rays via annihilation or decay detectable by the Fermi Large Area Telescope (LAT). A detection of WIMPs would also indicate the existence of physics beyond the Standard Model. We present recent results from the two cleanest indirect WIMP searches by the Fermi-LAT Collaboration: searches for γ-ray spectral lines and γ-ray emission associated with Milky Way dwarf spheroidal satellite galaxies.

  7. The Honorable Wellington E. Webb 350 City County Building

    Office of Legacy Management (LM)

    W. Alexander Willianp,301-427-1719 of'my staff. 'James W. Wagoner II : Director Off-SiteSavannah River Program Division' Office of Eastern Area Programs Office of Environmental ...

  8. Space Electronics and Signal Processing (ISR-4)

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

    4 Space Electronics and Signal Processing Developing custom sensors, instruments, and ... Quality, reliable instruments for demanding space environments The Space Electronics and ...

  9. DREAM tool increases space weather predictions

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

    DREAM tool increases space weather predictions Model addresses radiation hazards of the space environment on space systems. April 13, 2012 Scientists studying Earth's radiation ...

  10. In the OSTI Collections: the Space Environment and Space Technology...

    Office of Scientific and Technical Information (OSTI)

    ... Experiments with fast-moving heavy ions are needed to duplicate ... Weld Joints with Liquid Sodium-Potassium Coolants for Fission Surface Power Reactors for Lunar and Space ...

  11. OBSERVATIONS OF MILKY WAY DWARF SPHEROIDAL GALAXIES WITH THE FERMI-LARGE AREA TELESCOPE DETECTOR AND CONSTRAINTS ON DARK MATTER MODELS

    SciTech Connect (OSTI)

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Bechtol, K.; Berenji, B.; Bloom, E. D.; Borgland, A. W.; Atwood, W. B.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Bastieri, D.; Bonamente, E.; Brigida, M.; Bruel, P.; Buson, S. E-mail: cohen@slac.stanford.ed E-mail: Eric.NUSS@lpta.in2p3.f

    2010-03-20

    We report on the observations of 14 dwarf spheroidal galaxies (dSphs) with the Fermi Gamma-Ray Space Telescope taken during the first 11 months of survey mode operations. The Fermi telescope, which is conducting an all-sky gamma-ray survey in the 20 MeV to >300 GeV energy range, provides a new opportunity to test particle dark matter models through the expected gamma-ray emission produced by pair annihilation of weakly interacting massive particles (WIMPs). Local Group dSphs, the largest galactic substructures predicted by the cold dark matter scenario, are attractive targets for such indirect searches for dark matter because they are nearby and among the most extreme dark matter dominated environments. No significant gamma-ray emission was detected above 100 MeV from the candidate dwarf galaxies. We determine upper limits to the gamma-ray flux assuming both power-law spectra and representative spectra from WIMP annihilation. The resulting {integral} flux above 100 MeV is constrained to be at a level below around 10{sup -9} photons cm{sup -2} s{sup -1}. Using recent stellar kinematic data, the gamma-ray flux limits are combined with improved determinations of the dark matter density profile in eight of the 14 candidate dwarfs to place limits on the pair-annihilation cross section of WIMPs in several widely studied extensions of the standard model, including its supersymmetric extension and other models that received recent attention. With the present data, we are able to rule out large parts of the parameter space where the thermal relic density is below the observed cosmological dark matter density and WIMPs (neutralinos here) are dominantly produced non-thermally, e.g., in models where supersymmetry breaking occurs via anomaly mediation. The gamma-ray limits presented here also constrain some WIMP models proposed to explain the Fermi and PAMELA e {sup +} e {sup -} data, including low-mass wino-like neutralinos and models with TeV masses pair annihilating into

  12. No Prejudice in Space

    SciTech Connect (OSTI)

    Cotta, R.C.; Gainer, J.S.; Hewett, J.L.; Rizzo, T.G.; /SLAC

    2010-08-26

    We present a summary of recent results obtained from a scan of the 19-dimensional parameter space of the pMSSM and its implications for dark matter searches. We have generated a large set of points in parameter space (which we call 'models') for the 19-parameter CP-conserving pMSSM, where MFV has been assumed. We subjected these models to numerous experimental and theoretical constraints to obtain a set of {approx}68 K models which are consistent with existing data. We attempted to be somewhat conservative in our implementation of these constraints; in particular we only demanded that the relic density of the LSP not be greater than the measured value of {Omega}H{sup 2} for non-baryonic dark matter, rather than assuming that the LSP must account for the entire observed relic density. Examining the properties of the neutralinos in these models, we find that many are relatively pure gauge eigenstates with Higgsinos being the most common, followed by Winos. The relative prevalence of Higgsino and Wino LSPs leads many of our models to have a chargino as nLSP, often with a relatively small mass splitting between this nLSP and the LSP; this has important consequences in both collider and astroparticle phenomenology. We find that, in general, the LSP in our models provides a relatively small ({approx} 4%) contribution to the dark matter, however there is a long tail to this distribution and a substantial number of models for which the LSP makes up all or most of the dark matter. Typically these neutralinos are mostly Binos. Examining the signatures of our models in direct and indirect dark matter detection experiments, we find a wide range of signatures for both cases. In particular, we find a much larger range of WIMP-nucleon cross sections than is found in any particular model of SUSY-breaking. As these cross sections also enter the regions of parameter space suggested by non-SUSY models, it appears that the discovery of WIMPs in direct detection experiments might not

  13. Space Instrument Realization (ISR-5)

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

    Space Heating and Cooling Products and Services Space Heating and Cooling Products and Services Get tips on heating and cooling product information and services. | Photo courtesy of <a href="http://www.flickr.com/photos/activesteve/5259747234/">Flickr user ActiveSteve</a>. Get tips on heating and cooling product information and services. | Photo courtesy of Flickr user ActiveSteve. Use the following links to get product information and locate professional services for space

  14. Constrained space camera assembly

    DOE Patents [OSTI]

    Heckendorn, F.M.; Anderson, E.K.; Robinson, C.W.; Haynes, H.B.

    1999-05-11

    A constrained space camera assembly which is intended to be lowered through a hole into a tank, a borehole or another cavity is disclosed. The assembly includes a generally cylindrical chamber comprising a head and a body and a wiring-carrying conduit extending from the chamber. Means are included in the chamber for rotating the body about the head without breaking an airtight seal formed therebetween. The assembly may be pressurized and accompanied with a pressure sensing means for sensing if a breach has occurred in the assembly. In one embodiment, two cameras, separated from their respective lenses, are installed on a mounting apparatus disposed in the chamber. The mounting apparatus includes means allowing both longitudinal and lateral movement of the cameras. Moving the cameras longitudinally focuses the cameras, and moving the cameras laterally away from one another effectively converges the cameras so that close objects can be viewed. The assembly further includes means for moving lenses of different magnification forward of the cameras. 17 figs.

  15. Drill string splined resilient tubular telescopic joint for balanced load drilling of deep holes

    SciTech Connect (OSTI)

    Garrett, W.R.

    1984-03-06

    A drill string splined resilient tubular telescopic joint for balanced load deep well drilling comprises a double acting damper having a very low spring rate upon both extension and contraction from the zero deflection condition. Stacks of spring rings are employed for the spring means, the rings being either shaped elastomer-metal sandwiches or, preferably, roller Belleville springs. The spline and spring means are disposed in an annular chamber formed by mandrel and barrel members constituting the telescopic joint. The chamber containing the spring means, and also containing the spline means, is filled with lubricant, the chamber being sealed with a pressure seal at its lower end and an inverted floating seal at its upper end. A prototype includes of this a bellows seal instead of the floating seal at the upper end of the tool, and a bellows in the side of the lubricant chamber provides volume compensation. A second lubricant chamber is provided below the pressure seal, the lower end of the second chamber being closed by a bellows seal and a further bellows in the side of the second chamber providing volume compensation. Modifications provide hydraulic jars.

  16. DISCOVERY OF TWO MILLISECOND PULSARS IN FERMI SOURCES WITH THE NANCAY RADIO TELESCOPE

    SciTech Connect (OSTI)

    Cognard, I.; Johnson, T. J.; Harding, A. K.; Ferrara, E. C.; Smith, D. A.; Dumora, D.; Wolff, M. T.; Grove, J. E.; Cheung, C. C.; Abdo, A. A.; Donato, D.; Ballet, J.; Desvignes, G.; Johnston, S.; Keith, M. E-mail: guillemo@mpifr-bonn.mpg.de

    2011-05-01

    We report the discovery of two millisecond pulsars in a search for radio pulsations at the positions of Fermi-Large Area Telescope sources with no previously known counterparts, using the Nancay Radio Telescope. The two millisecond pulsars, PSRs J2017+0603 and J2302+4442, have rotational periods of 2.896 and 5.192 ms and are both in binary systems with low-eccentricity orbits and orbital periods of 2.2 and 125.9 days, respectively, suggesting long recycling processes. Gamma-ray pulsations were subsequently detected for both objects, indicating that they power the associated Fermi sources in which they were found. The gamma-ray light curves and spectral properties are similar to those of previously detected gamma-ray millisecond pulsars. Detailed modeling of the observed radio and gamma-ray light curves shows that the gamma-ray emission seems to originate at high altitudes in their magnetospheres. Additionally, X-ray observations revealed the presence of an X-ray source at the position of PSR J2302+4442, consistent with thermal emission from a neutron star. These discoveries along with the numerous detections of radio-loud millisecond pulsars in gamma rays suggest that many Fermi sources with no known counterpart could be unknown millisecond pulsars.

  17. First lunar occultation results from the 2.4 m Thai national telescope equipped with ULTRASPEC

    SciTech Connect (OSTI)

    Richichi, A.; Irawati, P.; Soonthornthum, B.; Dhillon, V. S.; Marsh, T. R.

    2014-11-01

    The recently inaugurated 2.4 m Thai National Telescope (TNT) is equipped with, among other instruments, the ULTRASPEC low-noise, frame-transfer EMCCD camera. At the end of its first official observing season, we report on the use of this facility to record high time resolution imaging using small detector subarrays with a sampling as fast as several 10{sup 2} Hz. In particular, we have recorded lunar occultations of several stars that represent the first contribution to this area of research made from Southeast Asia with a telescope of this class. Among the results, we discuss an accurate measurement of α Cnc, which has been reported previously as a suspected close binary. Attempts by several authors to resolve this star have so far met with a lack of unambiguous confirmation. With our observation we are able to place stringent limits on the projected angular separation (<0.''003) and brightness (Δm > 5) of a putative companion. We also present a measurement of the binary HR 7072, which extends considerably the time coverage available for its yet undetermined orbit. We discuss our precise determination of the flux ratio and projected separation in the context of other available data. We conclude by providing an estimate of the performance of ULTRASPEC at TNT for lunar occultation work. This facility can help to extend the lunar occultation technique in a geographical area where no comparable resources were available until now.

  18. TANK SPACE ALTERNATIVES ANALYSIS REPORT

    SciTech Connect (OSTI)

    TURNER DA; KIRCH NW; WASHENFELDER DJ; SCHAUS PS; WODRICH DD; WIEGMAN SA

    2010-04-27

    This report addresses the projected shortfall of double-shell tank (DST) space starting in 2018. Using a multi-variant methodology, a total of eight new-term options and 17 long-term options for recovering DST space were evaluated. These include 11 options that were previously evaluated in RPP-7702, Tank Space Options Report (Rev. 1). Based on the results of this evaluation, two near-term and three long-term options have been identified as being sufficient to overcome the shortfall of DST space projected to occur between 2018 and 2025.

  19. Phase space quantum mechanics - Direct

    SciTech Connect (OSTI)

    Nasiri, S.; Sobouti, Y.; Taati, F.

    2006-09-15

    Conventional approach to quantum mechanics in phase space (q,p), is to take the operator based quantum mechanics of Schroedinger, or an equivalent, and assign a c-number function in phase space to it. We propose to begin with a higher level of abstraction, in which the independence and the symmetric role of q and p is maintained throughout, and at once arrive at phase space state functions. Upon reduction to the q- or p-space the proposed formalism gives the conventional quantum mechanics, however, with a definite rule for ordering of factors of noncommuting observables. Further conceptual and practical merits of the formalism are demonstrated throughout the text.

  20. Space Week | Department of Energy

    Office of Environmental Management (EM)

    fiction and what could one day be science fact? | Photo Credit: NASA. From powering space travel to energizing weapons, energy technology plays a prominent role in science fiction. ...

  1. Radioisotopes: Energy for Space Exploration

    SciTech Connect (OSTI)

    Carpenter, Bob; Green, James; Bechtel, Ryan

    2011-01-01

    Through a strong partnership between the Energy Department's office of Nuclear Energy and NASA, Radioisotope Power Systems have been providing the energy for deep space exploration.

  2. Radioisotopes: Energy for Space Exploration

    ScienceCinema (OSTI)

    Carpenter, Bob; Green, James; Bechtel, Ryan

    2013-05-29

    Through a strong partnership between the Energy Department's office of Nuclear Energy and NASA, Radioisotope Power Systems have been providing the energy for deep space exploration.

  3. THE NUCLEAR SPECTROSCOPIC TELESCOPE ARRAY (NuSTAR) HIGH-ENERGY...

    Office of Scientific and Technical Information (OSTI)

    Columbia University, New York, NY 10027 (United States); Zhang, William W. NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Boggs, Steven E....

  4. Space Conditioning Standing Technical Committee Strategic Plan...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Committee Strategic Plan Space Conditioning Standing Technical Committee Strategic Plan ... identified by the Building America Space Conditioning Standing Technical Committee. ...

  5. Building America Webinar: Retrofitting Central Space Conditioning...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Space Conditioning Strategies for Multifamily Buildings - Introduction This ... mproving the performance of central space conditioning systems in multifamily buildings. ...

  6. Space and Remote Sensing (ISR-2)

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

    Space Week Space Week Space Week Preventing Space Traffic Jams With around one thousand active satellites and the tens of thousands of pieces of space junk orbiting Earth, space is getting exceedingly crowded. Researchers at Lawrence Livermore National Lab are working on a system that could help prevent collisions in space. | Graphic by <a href="/node/379579">Sarah Gerrity</a>, Energy Department. With space getting exceedingly crowded, researchers at Lawrence Livermore

  7. Gamma-ray burst observations with new generation imaging atmospheric Cerenkov Telescopes in the FERMI era

    SciTech Connect (OSTI)

    Covino, S.; Campana, S.; Galante, N.; Gaug, M.; Longo, F.; Scapin, V.

    2009-04-08

    After the launch and successful beginning of operations of the FERMI satellite, the topics related to high-energy observations of gamma-ray bursts have obtained a considerable attention by the scientific community. Undoubtedly, the diagnostic power of high-energy observations in constraining the emission processes and the physical conditions of gamma-ray burst is relevant. We briefly discuss how gamma-ray burst observations with ground-based imaging array Cerenkov telescopes, in the GeV-TeV range, can compete and cooperate with FERMI observations, in the MeV-GeV range, to allow researchers to obtain a more detailed and complete picture of the prompt and afterglow phases of gamma-ray bursts.

  8. On the Sensitivity of Neutrino Telescopes to a Modified Dispersion Relation

    SciTech Connect (OSTI)

    Bustamante, M.; Gago, A. M.; Bazo, J. L.; Miranda, O. G.

    2008-07-02

    We consider a modified dispersion relation and its effect on the flavour ratios of high-energy neutrinos originated at distant astrophysical sources such as active galactic nuclei. This dispersion relation arise naturally in different new physics (NP) effects such as violation of CPT invariance, of the equivalence principle and of Lorentz invariance. It is a common notion in the literature that by using the flux of high-energy neutrinos expected from distant astrophysical sources, the sensitivity to possible NP effects may be improved beyond the current bounds. However, performing a realistic analysis that takes into account the expected number of events in future neutrino telescopes, we find that the average detected flavour ratios with and without the inclusion of new physics have essentially the same value, making difficult to obtain an improved bound for this type of new physics.

  9. NEW SOLAR TELESCOPE OBSERVATIONS OF MAGNETIC RECONNECTION OCCURRING IN THE CHROMOSPHERE OF THE QUIET SUN

    SciTech Connect (OSTI)

    Chae, Jongchul; Ahn, K.; Goode, P. R.; Yurchysyn, V.; Abramenko, V.; Andic, A.; Cao, W.; Park, Y. D.

    2010-04-10

    Magnetic reconnection is a process in which field-line connectivity changes in a magnetized plasma. On the solar surface, it often occurs with the cancellation of two magnetic fragments of opposite polarity. Using the 1.6 m New Solar Telescope, we observed the morphology and dynamics of plasma visible in the H{alpha} line, which is associated with a canceling magnetic feature (CMF) in the quiet Sun. The region can be divided into four magnetic domains: two pre-reconnection and two post-reconnection. In one post-reconnection domain, a small cloud erupted, with a plane-of-sky speed of 10 km s{sup -1}, while in the other one, brightening began at points and then tiny bright loops appeared and subsequently shrank. These features support the notion that magnetic reconnection taking place in the chromosphere is responsible for CMFs.

  10. Note on quantum Minkowski space

    SciTech Connect (OSTI)

    Bentalha, Z.; Tahiri, M.

    2008-09-15

    In this work, some interesting details about quantum Minkowski space and quantum Lorentz group structures are revealed. The task is accomplished by generalizing an approach adopted in a previous work where quantum rotation group and quantum Euclidean space structures have been investigated. The generalized method is based on a mapping relating the q-spinors (precisely the tensor product of dotted and undotted fondamental q-spinors) to Minkowski q-vectors. As a result of this mapping, the quantum analog of Minkowski space is constructed (with a definite metric). Also, the matrix representation of the quantum Lorentz group is determined together with its corresponding q-deformed orthogonality relation.