14 juin - 17 juin 2016


S05 R��union des utilisateurs des t��lescopes fran��ais (TBL/OHP193)

Distribution of baryonic and dark matter in spiral and irregular galaxies

Marie Korsaga, Philippe Amram, Claude Carignan, Benoit Epinat

The formation of galaxies is set by the gravitational growth of dark matter halos and the dynamics of gas in these halos. Cosmological numerical simulations predict a cuspy dark halo density profile while the observations show a core density profile distribution. The question of the exact shape of the dark matter halo density profile remains open until today. To lift this mystery, we are working on 203 spiral and irregular local galaxies observed with the Fabry-Perot interferometer around the Halpha emission line. We combine the kinematic data from observations to the photometric data (R and near infrared band) already available in the litterature to determine the distribution of the dark matter in the inner region of galaxies with three models like the Isothermal sphere, the NFW profile and the theory of MOND. The aim is to find the most likely distribution and then to limit the range of the possible distribution of the dark matter halo in local galaxies.