A Catalog of Candidate Intermediate-Luminosity X-Ray Objects

By E. Colbert, A. Ptak. 2002

156 citations recorded by the source corpus.

ROSAT, and now Chandra, X-ray images allow studies of extranuclear X-ray point sources in galaxies other than our own. X-ray observations of normal galaxies with ROSAT and Chandra have revealed that off-nuclear, compact, intermediate-luminosity (LX[2-10 keV] ≥1039.0 ergs s-1) X-ray objects (IXOs, a.k.a. ULXs [ultraluminous X-ray sources]) are quite common. Here we present a catalog and finding charts for 87 IXOs in 54 galaxies, derived from all of the ROSAT HRI imaging data for galaxies with cz ≤ 5000 km s-1 from the Third Reference Catalog of Bright Galaxies. We have defined the cutoff LX for IXOs so that it is well above the Eddington luminosity of a 1.4 M☉ black hole (1038.3 ergs s-1), so as not to confuse IXOs with "normal" black hole X-ray binaries. This catalog is intended to provide a baseline for follow-up work with Chandra and XMM-Newton, and with space- and ground-based survey work at wavelengths other than X-ray. We demonstrate that elliptical galaxies with IXOs have a larger number of IXOs per galaxy than nonelliptical galaxies with IXOs and note that they are not likely to be merely high-mass X-ray binaries with beamed X-ray emission, as may be the case for IXOs in starburst galaxies. Approximately half of the IXOs with multiple observations show X-ray variability, and many (19) of the IXOs have faint optical counterparts in DSS optical B-band images. Follow-up observations of these objects should be helpful in identifying their nature.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics, Radiation

View Paper: https://www.semanticscholar.org/paper/32033bf433a2338dd91b72318c1c3347bb9f6f8b

How researchers see this paper

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In Astronomy and Astrophysics

1. G. Fabbiano
2. H. Feng
3. R. Soria
4. E. Colbert
5. T. Roberts
6. M. Miller
7. T. Heckman
8. K. Weaver

In Nuclear and High Energy Physics

1. G. Fabbiano
2. R. Soria
3. H. Feng
4. M. Miller
5. T. Roberts
6. J. Wilms
7. A. Stobbart
8. E. Colbert

In Radiation

1. G. Fabbiano
2. M. Miller
3. T. Roberts
4. J. Wilms
5. A. Stobbart
6. H. Feng
7. A. Tennant
8. R. Soria

Citations in the corpus

• On the formation and evolution of black hole binaries (2002, background): “They were originally discovered by Einstein (Fabbiano 1989) and have been found in large numbers by ROSAT and most recently Chandra (Colbert & Mushotzky 1999; Roberts & Warwick 2000; Colbert & Ptak 2002; Lira, Johnson & Lawrence 2002; Jeltema et al. 2002).”
• Populations of X-Ray Sources in Galaxies (2006, background): “They also point out that ULX detections in early-type galaxies are significantly contaminated by background AGNs, in agreement with the statistical works of Ptak & Colbert (2004) and Colbert & Ptak (2002), which are based on ROSAT HRI (5′ ′ resolution) observations of galaxies.”
• Ultraluminous X-ray sources in the Chandra and XMM-Newton era (2011, background): “Larger and more systematic X-ray source catalogs based on re-analysis of archivalROSAT/HRI data soon followed: in particular, by Roberts & Warwick (2000), by Colbert & Ptak (2002), and by Liu & Bregman (2005), which included 106 sources above 1039 erg s−1.”
• X-Ray Spectroscopic Evidence for Intermediate-Mass Black Holes: Cool Accretion Disks in Two Ultraluminous X-Ray Sources (2002, background): “Variability was observed inROSAT/HRI observations of these sources (Colbert & Ptak 2002).”
• Black Hole Mass and Spin Coevolution by Mergers (2002, background): “…and supermassive holes (M ∼ 106−109M⊙) in galactic bulges [e.g., Ferrarese (2002); Kormendy & Gebhardt (2001)] is extremely strong; tantalizing evidence suggests middleweight holes (M ∼ 102 − 104M⊙) as well (Colbert & Mushotzky 1999; Colbert & Ptak 2002; Gebhardt et al. 2000; van der Marel 2001).”
• XMM–Newton observations of the brightest ultraluminous X-ray sources (2006, methodology): “…& Singh (1997),e Foschini et al. (2004),f Ho, Filippenko, & Sargent (1997),g Schlegel et al. (2000),h Miller et al. (2003), i Tully (1988), j Colbert & Ptak (2002),k Zampieri et al. (2004),l Schlegel & Pannuti (2003), m Kaaret, Ward, & Zezas (2004),n Miller et al. (2004a),o Ramsey et al.…”
• The Ultraluminous X-Ray Source Population from the Chandra Archive of Galaxies (2004, background): “ROSAT has extended this list to nearly 100 (Roberts & Warwick 2000; Colbert & Ptak 2002).”
• X-Ray Spectral Properties of Low-Mass X-Ray Binaries in Nearby Galaxies (2002, background): “A substantial number of high luminosity Xray sources in early-type galaxies was found by Colbert & Ptak (2002) in a survey with the ROSAT HRI, although the lack of spectral resolution of that instrument did not allow for a spectral comparison of these sources to ULXs in spiral galaxies.”
• Intermediate - mass black holes (2003, methodology): “Colbert & Ptak (2002) estimate random variability of >∼ 50% in over half of all ULXs, eliminating supernovae or XRB-clusters as likely scenarios.”
• Old and Young X-Ray Point Source Populations in Nearby Galaxies (2003, background): “We know that ULXs in elliptical galaxies (e.g. Colbert & Ptak 2002) are from older populations, since they have negligible star formation.”