1111.0830 (Benedetta Vulcani et al.)

The galaxy stellar mass function and its evolution with time show no dependence on global environment    [PDF]

Benedetta Vulcani, Bianca M. Poggianti, August Oemler Jr., Alan Dressler, Alfonso Aragon-Salamanca, Gabriella De Lucia, Mike Gladders, Louis Abramson, Claire Halliday

We present the analysis of the galaxy stellar mass function in different environments at intermediate redshift (0.3 10^{10.5} M_sun, to study cluster, group, and field galaxies at z=0.3-0.45, and the ESO Distant Cluster Survey (EDisCS), at masses M_ast > 10^{10.2} M_sun, to investigate cluster and group galaxies at z=0.4-0.8. Therefore, in our analysis we include galaxies that are slightly less massive than the Milky Way. Having excluded the brightest cluster galaxies, we show that the mass distribution does not seem to depend on global environment. Our two main results are: (1) Galaxies in the virialized regions of clusters and in the field follow a similar mass distribution. (2) Comparing both ICBS and EDisCS mass functions to mass functions in the local Universe, we find evolution from z~0.4-0.6 to z~0.07. The population of low-mass galaxies has proportionally grown with time with respect to that of massive galaxies. This evolution is independent of environment -- the same for clusters and the field. Furthermore, considering only clusters, we find that within the virialized regions, central parts may be proportionally more populated by more massive galaxies than outer parts, while no differences are detected when we compare galaxies within and outside the virial radius. Subdividing galaxies in terms of colour, in clusters, groups, and field red and blue galaxies are regulated by different mass functions, but comparing separately the blue and red mass functions in different environments, no differences are detected.

View original: http://arxiv.org/abs/1111.0830