A Complete Sample of ULX Host Galaxies
Abstract
One hundred seven ultraluminous X-ray (ULX) sources with 0.3-10.0 keV luminosities in excess of 1e39 erg/s are identified in a complete sample of 127 nearby galaxies. The sample includes all galaxies within 14.5 Mpc above the completeness limits of both the Uppsala Galaxy Catalog and the Infrared Astronomical Satellite survey. This represents the least-biased ULX host galaxy sample to date. The galaxy sample spans all Hubble types and a range of four decades in mass and in star-formation rate. ULXs are detected in this sample at a rate of 0.5 per 1e10 solar masses and 2.7 per solar mass/year star-formation rate.
At these rates we predict as many as 15 additional ULXs remain undetected in fainter dwarf galaxies within the survey volume. Less than 13 of the 107 ULX candidates are expected to be background interlopers. Properties of the sample galaxies and a census of the ULX candidate population are presented.- Publication:
-
American Astronomical Society Meeting Abstracts #218
- Pub Date:
- May 2011
- Bibcode:
- 2011AAS...21822807S