Searching for Intermediate Mass Black Holes in Ultraluminous X-ray Binaries
Abstract
We are beginning to understand the frequency of black hole mergers thanks to recent observations by LIGO. However, these observations do not tell us anything directly about Intermediate Mass Black Holes (IMBHs), and the merger products do not suggest that the mergers are a viable formation mechanism of "true" IMBHs. We still don't know how rapidly IMBHs grow, how frequently they merge, and whether they represent a step in the evolution of supermassive black holes, although that seems increasingly unlikely. We conduct a volume-limited archival survey of all Chandra X-ray Observatory sources in galaxies within 15 Mpc of the Earth that aims to locate and analyze IMBHs. Here, an IMBH is defined as any black hole whose mass exceeds the threshold where it is likely to form from a single progenitor star. We perform a multiwavelength analysis of the highest-count sources in this sample, in the hope of discovering an intermediate mass black hole. We identify an IMBH candidate in NGC 4631, as well as four candidate super-Eddington neutron stars in other nearby galaxies, and examine the optical environments around these sources in the hopes of further characterizing their nature.
- Publication:
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American Astronomical Society Meeting Abstracts #233
- Pub Date:
- January 2019
- Bibcode:
- 2019AAS...23336916F