Formation et Evolution des Galaxies - Groupe de Recherche IAP

Date	Sujet	Présenté par
24 janvier 2013	The mass and velocity anisotropy profile of Abell 2142 Abell 2142 is a nearby cluster with one of the largest available spectroscopic data-set, comparable to the well known Coma cluster. Hence, it is one of the best observational target for the determination of a cluster mass and velocity anisotropy profile. For this I apply different techniques, all based on the projected phase-space distribution of galaxies in the cluster region: Dispersion+Kurtosis (Lokas & Mamon 2001), MAMPOSSt (Mamon et al. 2013) and Caustic (Diaferio & Geller 1997). I combine the different mass profile determinations, along with those obtained in the literature based on X-ray and weak lensing observations, to define a concordance mass profile for the cluster. I then use this mass profile to compute the velocity anisotropy profile, which is related to the shape of galaxy orbits in the cluster, and can be used to constrain formation scenarios of cosmological halos. I finally compare the velocity anisotropy profile of Abell 2142 to those of cosmological halos of similar mass in numerical N-body SPH simulations.	Emiliano Munari Univ. Trieste, Italie