Skip to content

Extended X-ray emission at high redshifts: radio galaxies versus clusters

A. Celotti, A. C. Fabian

astro-pharXiv:astro-ph/0405622

Abstract

Most old distant radio galaxies should be extended X-ray sources due to inverse Compton scattering of Cosmic Microwave Background (CMB) photons. Such sources can be an important component in X-ray surveys for high redshift clusters, due to the increase with redshift of both the CMB energy density and the radio source number density. We estimate a lower limit to the space density of such sources and show that inverse Compton scattered emission may dominate above redshifts of one and X-ray luminosities of 1044 erg/s, with a space density of radio galaxies > 10-8 Mpc-3. The X-ray sources may last longer than the radio emission and so need not be associated with what is seen to be a currently active radio galaxy.

Create a lesson