A new globular cluster black hole in NGC 4472
Abstract
We discuss CXOU 1229410+075744, a new black hole candidate in a globular cluster in the elliptical galaxy NGC 4472. By comparing two Chandra observations of the galaxy, we find a source that varies by at least a factor of 4, and has a peak luminosity of at least 2 × 1039 erg s-1. As such, the source varies by significantly more than the Eddington luminosity for a single neutron star, and is a strong candidate for being a globular cluster black hole. The source's X-ray spectrum also evolves in a manner consistent with what would be expected from a single accreting stellar mass black hole. We consider the properties of the host cluster of this source and the six other strong black hole X-ray binary candidates, and find that there is suggestive evidence that black hole X-ray binary formation is favoured in bright and metal-rich clusters, just as is the case for bright X-ray sources in general.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- January 2011
- DOI:
- 10.1111/j.1365-2966.2010.17547.x
- arXiv:
- arXiv:1008.2896
- Bibcode:
- 2011MNRAS.410.1655M
- Keywords:
-
- binaries: general;
- stars: kinematics and dynamics;
- globular clusters: general;
- Astrophysics - High Energy Astrophysical Phenomena;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 6 pages, one 2-panel figure, 2 tables