The hyperluminous X-ray source candidate in IC 4320: another HLX bites the dust

Sutton, A.D.; Roberts, T.P.; Gladstone, J.C.; Walton, D.J.

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.

Citation

Sutton, A., Roberts, T., Gladstone, J., & Walton, D. (2015). The hyperluminous X-ray source candidate in IC 4320: another HLX bites the dust. Monthly Notices of the Royal Astronomical Society, 450(1), 787-793. https://doi.org/10.1093/mnras/stv505

• Journal Article Type: Article
• Acceptance Date: Mar 4, 2015
• Publication Date: Jun 11, 2015
• Deposit Date: Apr 30, 2015
• Publicly Available Date: May 6, 2015
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Royal Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 450
• Issue: 1
• Pages: 787-793
• DOI: https://doi.org/10.1093/mnras/stv505
• Keywords: Accretion, Accretion discs, Black hole physics, X-rays: binaries, X-rays: galaxies.
• Related Public URLs: http://arxiv.org/abs/1503.01711