Formation et Evolution des Galaxies - Groupe de Recherche IAP

Date	Sujet	Présenté par
17 avril 2014	Toward mass distribution models of spiral galaxies in 2D Mass distribution models of nearby galactic disks have long been based on the analysis of (1D) rotation curves. We have recently developed a new method that allows to fit dark matter halo parameters directly from their observed (2D) velocity field. The 2D circular velocity contribution of the baryonic, luminous matter is inferred from their (3D) gravitational potential, as calculated the hyperkernel method proposed by Huré (2013), and from stellar and gas surface density maps. We will present the first results for the two nearby spirals Messier 99 and Messier 100, and describe some of the advantages offered by this new kind of 2D mass modeling with respect to the usual fit of the rotation curve: increase from tens to thousands the number of degrees of freedom useful to the least-square fits, show how asymmetric is the circular velocity contribution of baryons, enable the possibility of fitting density laws for dark matter haloes more complex than a sphere.	Laurent Chemin Lab. d'Astrophysique de Bordeaux