Rare objects in Globular Clusters: from dwarf novae to intermediate mass black holes
Mathieu Servillat
Harvard-Smithsonian Center for Astrophysics

Globular clusters are old, dense stellar systems which harbor an excess of X-ray sources compared to the number of X-ray sources in the Galactic plane. These X-ray sources, which are mainly close binaries, can be produced through dynamical encounters in the dense core of globular clusters, and are thus intimately linked to their dynamical evolution. After reviewing the nature of those X-ray sources, I will show the discovery of a dwarf nova in M13 and spectroscopic observations of dwarf novae in M22, in order to investigate the possible lack of these objects in globular clusters. Massive globular clusters are thought to harbor an intermediate mass black hole (10^2-4 solar masses) in their core. I will present the state of the search for those objects, marked by the detection and follow-up of the ultra-luminous source ESO 243-49 HLX-1 in a 100 Mpc distant galaxy.

Date:	Mardi, 30 novembre 2010
Time:	16:00
Where:	McGill University
	Ernest Rutherford Physics Building, R.E. Bell Conference Room (room 103)
Contact:	Robert Rutledge