Statistical Properties of Voids

LAURA CECCARELLI; CARLOS VALOTTO, AND DIEGO G. LAMBAS IATE, OAC, C ́RDOBA, ARGENTIN; DIEGO G. LAMBAS; NELSON PADILLA

COSMIC FRONTIERS,ASP Conference Series,

Astronomical Society of the Pacific

Lugar: San Francisco; Año: 2007; p. 287 - 289

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