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Identifications of Four Integral Sources in the Galactic Plane via CHANDRA LocalizationsHard X-ray imaging of the Galactic plane by the INTEGRAL satellite is uncovering large numbers of 20-100 keV "IGR" sources. We present results from Chandra, INTEGRAL, optical, and IR observations of four IGR sources: three sources in the Norma region of the Galaxy(1GR J16195-4945,IGR J16207-5129, and IGR J16167-4957) and one that is closer to the Galactic center (IGR 5171 95-4100). In all four cases, one relatively bright Chandra source is seen in the INTEGRAL error circle, and these are likely to be the soft X-ray counterparts of the IGR sources. They have hard 0.3-10 keV spectra with power-law photon indices of Gamma = 0.5-1.1. While many previously studied IGR sources show high column densities (NH approx. 10(exp 23)-10(exp 24)/sq cm), only IGR J16195-4945 has a column density that could be as high as 10(exp 23)/sq cm. Using optical and IR sky survey catalogs and our own photometry, we have obtained identifications for all four sources. The J-band magnitudes are in the range 14.9-10.4, and we have used the optical/IR spectral energy distributions (SEDs) to constrain the nature of the sources. Blackbody components with temperature lower limits of >9400 K for IGR J16195-4945 and >18,000 K for IGR J16207-5129 indicate that these are very likely high-mass X-ray binaries (HMXBs). However, for IGR 516167-4957 and IGR J17195-4100, low extinction and the SEDs indicate later spectral types for the putative companions, suggesting that these are not HMXBs.
Document ID
20070013996
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Tomsick, John A.
(California Univ., San Diego La Jolla, CA, United States)
Chaty, Sylvain
(Commissariat a l'Energie Atomique Paris, France)
Rodriquez, Jerome
(Commissariat a l'Energie Atomique Paris, France)
Foschini, Luigi
(Istituto di Astrofisica Spaziale e Fisica Cosmica Bologna, Italy)
Walter, Roland
(INTEGRAL Science Data Center Versoix, Switzerland)
Kaaret, Philip
(Iowa Univ. Iowa City, IA, United States)
Date Acquired
August 23, 2013
Publication Date
August 20, 2006
Publication Information
Publication: The Astrophysical Journal
Volume: 647
Issue: Part 1
Subject Category
Astronomy
Funding Number(s)
CONTRACT_GRANT: NNG05GC49G
CONTRACT_GRANT: I/R/046/04
CONTRACT_GRANT: NAS8-03060
CONTRACT_GRANT: COFIN 2004-023189
Distribution Limits
Public
Copyright
Other

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