Stellar and dark matter density in the Local Universe

Abstract

We calculate the mean density profiles for luminous and dark matter on distance scales $D\sim (1-100)$ Mpc around us using recent all-sky catalogs of galaxy groups. Within the Local Volume $(D<11\mathrm{Mpc})$ we derived the mean stellar density ${\Omega }_{\ast }=0.44\%$ in the critical density units and the mean total matter density ${\Omega }_m=0.17$. In the sphere with a radius of 40 Mpc these quantities drop to ${\Omega }_{\ast }=0.24-0.32\%$ and ${\Omega }_m=0.09-0.14$. In a larger volume within $D\sim 135$ Mpc the discussed densities become more uncertain: ${\Omega }_{\ast }=0.20-0.24\%$ and ${\Omega }_m=0.05-0.16$. We summarize that the major part of the cosmic dark matter locates outside the virial and collapsing zones of groups and clusters.

11 pages, 8 figures, 4 tables, accepted by AN