Large scale anisotropies on halo infall

CECCARELLI, LAURA; PAZ, DANTE; PADILLA, NELSON D; LAMBAS, DIEGO G.

Boletín de la Asociación Argentina de Astronomía

Asociación Argentina de Astronomía

Año: 2010 vol. 53 p. 3 - 6

1669-9521

We perform a statistical analysis of the peculiar velocity field around dark matter haloes in numerical simulations. We examine different properties of the infall 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 value along the direction of the minor axis of the LSSR, whereas along the direction of its major axis, it exhibits the smallest velocities. We also analyse the depen- dence of the matter velocity field on the local environment. The amplitude of the infall at high local density regions is larger than at low local density regions. The velocity field tends to be more laminar along the direction towards the minor axis of the LSSR.