Chandra Localizations and Spectra of Integral Sources in the Galactic Plane: The Cycle 9 Sample
Abstract
We report on 0.3-10 keV X-ray observations by the Chandra X-ray Observatory of the fields of 22 sources that were discovered as hard X-ray (20-100 keV) sources by the International Gamma-Ray Astrophysics Satellite ("IGR" sources). The observations were made during Chandra's 9th observing cycle, and their purpose is to localize the sources and to measure their soft X-ray spectra in order to determine the nature of the sources. We find very likely Chandra counterparts for 18 of the 22 sources. We discuss the implications for each source, considering previous results and new optical or infrared identifications, and we identify or suggest identifications for the nature of 16 of the sources. Two of the sources, IGR J14003-6326 and IGR J17448-3232, are extended on arcminute scales. We identify the former as a pulsar wind nebula with a surrounding supernova remnant (SNR) and the latter as an SNR. In the group of 242 IGR sources, there is only one other source that has previously been identified as an SNR. Seven of the sources are definite or candidate high-mass X-ray binaries (HMXBs). We confirm a previous identification of IGR J14331-6112 as an HMXB, and based on combinations of hard X-ray spectra, inferred distances and X-ray luminosities, and/or column density variations, we suggest that IGR J17404-3655, IGR J16287-5021, IGR J17354-3255, IGR J17507-2647, IGR J17586-2129, and IGR J13186-6257 are candidate HMXBs. Our results indicate or confirm that IGR J19267+1325, IGR J18173-2509, and IGR J18308-1232 are cataclysmic variables (CVs), and we suggest that IGR J15529-5029 may also be a CV. We confirm that IGR J14471-6414 is an active galactic nucleus (AGN), and we also suggest that IGR J19443+2117 and IGR J18485-0047 may be AGNs. Finally, we found Chandra counterparts for IGR J11098-6457 and IGR J18134-1636, but more information is required to determine the nature of these two sources.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 2009
- DOI:
- 10.1088/0004-637X/701/1/811
- arXiv:
- arXiv:0906.2577
- Bibcode:
- 2009ApJ...701..811T
- Keywords:
-
- black hole physics;
- infrared: stars;
- stars: individual: IGR J07295–1329 IGR J09485–4726 IGR J11098–6457 IGR J13186–6257 IGR J14003–6326 IGR J14331–6112 IGR J14471–6414 IGR J15529–5029 IGR J16287–5021 IGR J17354–3255 IGR J17404–3655 IGR J17448–3232 IGR J17461–2204 IGR J17487–3124 IGR J17507–2647 IGR J17586–2129 IGR J18134–1636 IGR J18173–2509 IGR J18308–1232 IGR J18485–0047 IGR J19267+1325 IGR J19443+2117;
- stars: neutron;
- white dwarfs;
- X-rays: stars;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 14 pages, Accepted by ApJ