Large scale anisotropies on halo infall

LAURA CECCARELLI; DANTE PAZ; NELSON PADILLA; DIEGO G LAMBAS

Salta

Congreso; 53ª Reunión Anual de la Asociación Argentina de Astronomía; 2010

IATE - UNSa

We perform a statistical analysis of the peculiar velocity field around darkmatter haloes in numerical simulations. We examine different properties of theinfall of material onto haloes and its relation to halo shapes and the large scale surrounding regions (LSSR).We find that the amplitude of the infall velocity field along the halo shape minor axis is larger than that along the major axis. We also report a strong anisotropy of the velocity field along the principal axes of the LSSR.The infall reaches a maximum valuealong the direction of the minor axis of the LSSR, whereas along the directionof its major axis, it exhibits the smallest velocities. We also analyse thedependence of the matter velocity field on the local environment. The amplitudeof the infall at high local density regions is larger than at lowlocal density regions.  The velocity field tends to be more laminar along thedirection towards the minor axis of the LSSR.