Seminar: Do Intermediate Mass Black Holes Exist? The Case of ESO 243-49 HLX-1

Dr Sean Farrell 

The University of Sydney

Download the pdf poster.

The debate about the existence of intermediate mass black holes with masses between ~100 - 100,000 Solar masses has raged for some time now, with no convincing evidence confirming their existence provided until recently. The current front-runner is the brightest ultra-luminous X-ray source HLX-1 in the galaxy ESO 243-49 with a record breaking maximum luminosity of ~1E42 erg/s. HLX-1 is ~400 times brighter than the Eddington limit of a 20 Solar mass black hole, and ~10 times brighter than the second brightest ultra-luminous X-ray source. I will present here a review of the current state of knowledge on this intriguing source and will outline the results of multi-wavelength studies from radio to gamma ray wavelengths. I will also present recent results obtained in near-IR to UV wavelengths with the Hubble space telescope, and radio observations taken with the Australia Telescope Compact Array. These results continue to suggest that HLX-1 contains a black hole with a mass between ~3,000 - 100,000 Solar masses, possibly the remnant of a dwarf galaxy that was accreted by the host galaxy.