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Title: Recent and Future Observations in the X-ray and Gamma-ray Bands: Chandra, Suzaku, GLAST, and NuSTAR

Abstract

This paper presents a brief overview of the accomplishments of the Chandra satellite that are shedding light on the origin of high energy particles in astrophysical sources, with the emphasis on clusters of galaxies. It also discusses the prospects for the new data to be collected with instruments recently launched -- such as Suzaku -- or those to be deployed in the near future, and this includes GLAST and NuSTAR.

Authors:
 [1];  [2]
  1. Stanford Linear Accelerator Center, Stanford CA 94305 (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
20719680
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 801; Journal Issue: 1; Conference: Conference on astrophysical sources of high energy particles and radiation, Torun (Poland), 20-24 Jun 2005; Other Information: DOI: 10.1063/1.2141828; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ASTRONOMY; COSMIC GAMMA SOURCES; COSMIC X-RAY SOURCES; GALAXY CLUSTERS; SATELLITES

Citation Formats

Madejski, Greg, and KIPAC, Stanford CA 94305. Recent and Future Observations in the X-ray and Gamma-ray Bands: Chandra, Suzaku, GLAST, and NuSTAR. United States: N. p., 2005. Web. doi:10.1063/1.2141828.
Madejski, Greg, & KIPAC, Stanford CA 94305. Recent and Future Observations in the X-ray and Gamma-ray Bands: Chandra, Suzaku, GLAST, and NuSTAR. United States. doi:10.1063/1.2141828.
Madejski, Greg, and KIPAC, Stanford CA 94305. Tue . "Recent and Future Observations in the X-ray and Gamma-ray Bands: Chandra, Suzaku, GLAST, and NuSTAR". United States. doi:10.1063/1.2141828.
@article{osti_20719680,
title = {Recent and Future Observations in the X-ray and Gamma-ray Bands: Chandra, Suzaku, GLAST, and NuSTAR},
author = {Madejski, Greg and KIPAC, Stanford CA 94305},
abstractNote = {This paper presents a brief overview of the accomplishments of the Chandra satellite that are shedding light on the origin of high energy particles in astrophysical sources, with the emphasis on clusters of galaxies. It also discusses the prospects for the new data to be collected with instruments recently launched -- such as Suzaku -- or those to be deployed in the near future, and this includes GLAST and NuSTAR.},
doi = {10.1063/1.2141828},
journal = {AIP Conference Proceedings},
number = 1,
volume = 801,
place = {United States},
year = {Tue Nov 22 00:00:00 EST 2005},
month = {Tue Nov 22 00:00:00 EST 2005}
}
  • This paper presents a brief overview of the accomplishments of the Chandra satellite that are shedding light on the origin of high energy particles in astrophysical sources, with the emphasis on clusters of galaxies. It also discusses the prospects for the new data to be collected with instruments recently launched--such as Suzaku--or those to be deployed in the near future, and this includes GLAST and NuSTAR.
  • The wide-band all-sky monitor (WAM) onboard Suzaku has the largest effective area in 300-5000 keV, and thus very powerful to constrain the E peak and high energy tail of gamma-ray burst prompt emission. Collaboration with GLAST will give us high-quality data of gamma-ray prompt emissions to probe and resolve the emission mechanism and central engine of gamma-ray bursts. Here we report initial results of the WAM and address on the collaboration with GLAST.
  • Prior to the launch of NuSTAR, it was not feasible to spatially resolve the hard (E > 10 keV) emission from galaxies beyond the Local Group. The combined NuSTAR data set, comprised of three ∼165 ks observations, allows spatial characterization of the hard X-ray emission in the galaxy NGC 253 for the first time. As a follow up to our initial study of its nuclear region, we present the first results concerning the full galaxy from simultaneous NuSTAR, Chandra, and Very Long Baseline Array monitoring of the local starburst galaxy NGC 253. Above ∼10 keV, nearly all the emission is concentrated withinmore » 100'' of the galactic center, produced almost exclusively by three nuclear sources, an off-nuclear ultraluminous X-ray source (ULX), and a pulsar candidate that we identify for the first time in these observations. We detect 21 distinct sources in energy bands up to 25 keV, mostly consisting of intermediate state black hole X-ray binaries. The global X-ray emission of the galaxy—dominated by the off-nuclear ULX and nuclear sources, which are also likely ULXs—falls steeply (photon index ≳ 3) above 10 keV, consistent with other NuSTAR-observed ULXs, and no significant excess above the background is detected at E > 40 keV. We report upper limits on diffuse inverse Compton emission for a range of spatial models. For the most extended morphologies considered, these hard X-ray constraints disfavor a dominant inverse Compton component to explain the γ-ray emission detected with Fermi and H.E.S.S. If NGC 253 is typical of starburst galaxies at higher redshift, their contribution to the E > 10 keV cosmic X-ray background is <1%.« less
  • We present an analysis of a pointed 141 ks Chandra high-resolution transmission gratings observation of the Be X-ray emitting star HD110432, a prominent member of the {gamma} Cas analogs. This observation represents the first high-resolution spectrum taken for this source as well as the longest uninterrupted observation of any {gamma} Cas analog. The Chandra light curve shows a high variability but its analysis fails to detect any coherent periodicity up to a frequency of 0.05 Hz. Hardness ratio versus intensity analyses demonstrate that the relative contributions of the [1.5-3] A, [3-6] A, and [6-16] A energy bands to the totalmore » flux change rapidly in the short term. The analysis of the Chandra High Energy Transmission Grating (HETG) spectrum shows that, to correctly describe the spectrum, three model components are needed. Two of those components are optically thin thermal plasmas of different temperatures (kT Almost-Equal-To 8-9 and 0.2-0.3 keV, respectively) described by the models vmekal or bvapec. The Fe abundance in each of these two components appears equal within the errors and is slightly subsolar with Z Almost-Equal-To 0.75 Z{sub Sun }. The bvapec model better describes the Fe L transitions, although it cannot fit well the Na XI Ly{alpha} line at 10.02 A, which appears to be overabundant. Two different models seem to describe well the third component. One possibility is a third hot optically thin thermal plasma at kT = 16-21 keV with an Fe abundance Z Almost-Equal-To 0.3 Z{sub Sun }, definitely smaller than for the other two thermal components. Furthermore, the bvapec model describes well the Fe K shell transitions because it accounts for the turbulence broadening of the Fe XXV and Fe XXVI lines with a v{sub turb} Almost-Equal-To 1200 km s{sup -1}. These two lines, contributed mainly by the hot thermal plasma, are significantly wider than the Fe K{alpha} line whose FWHM < 5 mA is not resolved by Chandra. Alternatively, the third component can be described by a power law with a photon index of {Gamma} = 1.56. In either case, the Chandra HETG spectrum establishes that each one of these components must be modified by distinct absorption columns. The analysis of a noncontemporaneous 25 ks Suzaku observation shows the presence of a hard tail extending up to at least 33 keV. The Suzaku spectrum is described with the sum of two components: an optically thin thermal plasma at kT Almost-Equal-To 9 keV and Z Almost-Equal-To 0.74 Z{sub Sun }, and a very hot second plasma with kT Almost-Equal-To 33 keV or, alternatively, a power law with photon index of {Gamma} = 1.58. In either case, each one of the two components must be affected by different absorption columns. Therefore, the kT = 8-9 keV component is definitely needed while the nature of the harder emission cannot be unambiguously established with the present data sets. The analysis of the Si XIII and S XV He-like triplets present in the Chandra spectrum points to a very dense (n{sub e} {approx} 10{sup 13} cm{sup -3}) plasma located either close to the stellar surface (r < 3R{sub *}) of the Be star or, alternatively, very close (r {approx} 1.5R{sub WD}) to the surface of a (hypothetical) white dwarf companion. We argue, however, that the available data support the first scenario.« less
  • We present results from the coordinated broadband X-ray observations of the extreme ultraluminous X-ray source Holmberg IX X-1 performed by NuSTAR, XMM-Newton, and Suzaku in late 2012. These observations provide the first high-quality spectra of Holmberg IX X-1 above 10 keV to date, extending the X-ray coverage of this remarkable source up to ∼30 keV. Broadband observations were undertaken at two epochs, between which Holmberg IX X-1 exhibited both flux and strong spectral variability, increasing in luminosity from L {sub X} = (1.90 ± 0.03) × 10{sup 40} erg s{sup –1} to L {sub X} = (3.35 ± 0.03) ×more » 10{sup 40} erg s{sup –1}. Neither epoch exhibits a spectrum consistent with emission from the standard low/hard accretion state seen in Galactic black hole binaries, which would have been expected if Holmberg IX X-1 harbors a truly massive black hole accreting at substantially sub-Eddington accretion rates. The NuSTAR data confirm that the curvature observed previously in the 3-10 keV bandpass does represent a true spectral cutoff. During each epoch, the spectrum appears to be dominated by two optically thick thermal components, likely associated with an accretion disk. The spectrum also shows some evidence for a nonthermal tail at the highest energies, which may further support this scenario. The available data allow for either of the two thermal components to dominate the spectral evolution, although both scenarios require highly nonstandard behavior for thermal accretion disk emission.« less