A minor merger scenario for the ultraluminous X-ray source ESO 243-49 HLX-1

Дата и время публикации : 2012-03-19T20:00:40Z

Авторы публикации и институты :
M. Mapelli
L. Zampieri
L. Mayer

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 10 pages, 5 figures, MNRAS, in press. Some typos fixed
Первичная категория: astro-ph.HE

Все категории : astro-ph.HE, astro-ph.CO

Краткий обзор статьи: The point-like X-ray source HLX-1 is the brightest known ultraluminous X-ray source and likely the strongest intermediate-mass black hole candidate. HLX-1 is hosted in the S0 galaxy ESO 243-49, but offset with respect to the nucleus, and its optical counterpart was identified with a massive star cluster. In this paper, we study, through N-body/smoothed particle hydrodynamics simulations, the scenario where ESO 243-49 is undergoing (or just underwent) a minor merger with a gas-rich low-mass late-type galaxy. The simulations suggest that the observed star formation rate (SFR) in ESO 243-49 is a consequence of the interaction and that the companion galaxy already underwent the second pericentre passage. We propose that the counterpart of HLX-1 coincides with the nucleus (and possibly with the nuclear star cluster) of the secondary galaxy. We estimate that, if the minor merger scenario is correct, the number density of X-ray sources similar to HLX-1 is ~10^-6 Mpc^-3.

Category: Physics