Statistical Properties of Voids

CECCARELLI, L.; VALOTTO, C.; LAMBAS, D. G.; PADILLA, N.

Cosmic Frontiers ASP Conference Series, Vol. 379

Año: 2007 vol. 379 p. 279 - 283

We perform a statistical study of the dynamical properties of voids and galaxies around voids in mock galaxy catalogues and in the 2dFGRS. We detect a redshift space distortion in the void-galaxy cross correlation function consistent with an outflow motion of void shells and we are able to measure this outflow using peculiar velocities in the mock catalogues. We compare outflow velocities to the non-linear theory model for the velocities surrounding an underdense region and find that our measurements are consistent with these predictions. We measure the velocity dispersion of galaxies in void shells and find that galaxies move faster in the direction parallel to the void walls. Also, these results are in agreement with direct measurements from full 3D numerical simulations.