3 May 2001CfA Colloquium

Title: Galaxy Clusters as seen by XMM

Speaker: Monique Arnaud

Abstract: I will discuss new results on galaxy clusters obtained with the X-ray observatory XMM-Newton, the second cornerstone of the ESA Horizon 2000 program. The exceptional sensitivity of XMM, associated with its spectro-imaging capabilities, allows us to map the temperature structure of the X-ray emitting intra-cluster medium with unprecedented accuracy. These data provide new information on the physics of merger events and cosmological structure formation, as well as on cluster dark matter content and distribution. At smaller scales, high-resolution spectroscopy reveals a new vision of the core of clusters of galaxies, in particular of the cooling central gas. These new data, inconsistent with simple cooling flow models, reveal the complexity of the physical processes at work, which are far from being understood. Furthermore, I will present the first results of XMM observations of very distant clusters, important probes for the determination of cosmological parameters.

Reference for students:

"Cosmology and clusters of galaxies with XMM: The X-ray Multi-Mirror Mission", Arnaud, 1998, in "Fundamental parameters in cosmology", Proceedings of the XXXIIIrd Moriond Astrophysics Meeting, ed. J.Tran Thanh Van, Y.Giraud-Heraud, F.Bouchet, T.Damour, Y. Mellier; Editions Frontieres, Paris.

"First Science with XMM-Newton", 2001, Special letters issue of Astronomy & Astrophysics, Vol 365, in particular L60 to L 110

Lunch with the students will be on Friday, May 4th at 12:00 in A-101.