The hyperluminous X-ray source candidate in IC 4320: another HLX bites the dust
Abstract
The known members of the class of hyperluminous X-ray sources (HLXs) are few in number, yet they are of great interest as they are regarded as the likeliest intermediate-mass black hole (IMBH) candidates amongst the wider population of ultraluminous X-ray sources (ULXs). Here we report optical photometry and spectroscopy of an HLX candidate associated with the galaxy IC 4320, that reveal it is a background AGN. We discuss the implications of the exclusion of this object from the small number of well-studied HLXs, that appears to accentuate the difference in characteristics between the good IMBH candidate ESO 243-49 HLX-1 and the small handful of other HLXs.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- June 2015
- DOI:
- 10.1093/mnras/stv505
- arXiv:
- arXiv:1503.01711
- Bibcode:
- 2015MNRAS.450..787S
- Keywords:
-
- accretion;
- accretion discs;
- black hole physics;
- X-rays: binaries;
- X-rays: galaxies;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 7 pages, 4 figures, accepted for publication in MNRAS