Propiedades y Anisotropías de la Acrecion de Satélites en un Universo ΛCDM

SGRÓ, MARIO AGUSTÍN; GARCÍA LAMBAS, DIEGO; VILLALÓN, CAROLINA INÉS

San Juan

Congreso; 59° Reunión Anual de la Asociación Argentina de Astronomía; 2016

ICATE

We use a dark matter only simulation to study the infall of satellites in the ΛCDM model. The large volume and resolution of the simulation, enabled us to identify ∼220.000 massive hosts haloes (M ≥ 10^13 M) surrounded by ∼ 700.000 satellites This sample allowed us to study the radial velocity profiles of all satellites as a function of their distance to the primary object. Furthermore, we analysed the dependence of the radial velocity distribution with respect to the mass of the host halo and its principal inertia axes, as well as the properties of the that are being accreted, such as their mass, angular momentum and shape. This study highlights some of the evolutionary intrinsic characteristics of haloes showing an excess of infalling satellites, although a smaller population of outflowing objects is also present; these arise from the continuing evolution of dark matter haloes, even though they are virialized. We find that the accretion process depends on the host galaxy mass, showing important differences between each population and according to the distance of the satellite with respect to the primary galaxy. In addition to that, satellites in the process of infall or outflow show different characteristics in their dark matter properties. We find an excess of inflowing and outflowing satellites in the radial velocity - distance phase-space, being the outflow excess higher in the high mass hosts subsample. Moreover, we show that the excess of infalling satellites is present at all distances for high mass hosts, even near the centre of the host halo.