Dynamical friction of radio galaxies in galaxy clusters

Abstract

The distribution of luminous radio galaxies in galaxy clusters has been observed to be concentrated in the inner region. We consider the role of dynamical friction of massive galaxies (M ~ 1012.5Msolar), assuming them to be hosts of luminous radio galaxies, and show that beginning with a Navarro-Frenk-White density profile of a cluster of mass Mcl ~ 1015Msolar of concentration c ~ 5 and collapsing at z ~ 1, the density profile of radio galaxies evolves to a profile of concentration c ~ 25, as observed, in a time-scale of t ~ 3-5 Gyr.