Using Chandra imaging spectroscopy and Very Large Array ( VLA ) L-band radio maps , we have identified radio sources at P _ { 1.4 GHz } \geq 5 \times 10 ^ { 23 } W Hz ^ { -1 } and X-ray point sources ( XPSs ) at L _ { 0.3 - 8 keV } \geq 5 \times 10 ^ { 42 } erg s ^ { -1 } in L > L ^ { * } galaxies in 12 high-redshift ( 0.4 < z < 1.2 ) clusters of galaxies .
The radio galaxies and XPSs in this cluster sample , chosen to be consistent with Coma Cluster progenitors at these redshifts , are compared to those found at low- z analyzed in Hart et al .
( 2009 ) .
Within a projected radius of 1 Mpc of the cluster cores , we find 17 cluster radio galaxies ( 11 with secure redshifts , including one luminous FR II radio source at z = 0.826 , and 6 more with host galaxy colors similar to cluster ellipticals ) .
The radio luminosity function ( RLF ) of the cluster radio galaxies as a fraction of the cluster red sequence ( CRS ) galaxies reveals significant evolution of this population from high- z to low- z , with higher power radio galaxies situated in lower temperature clusters at earlier epochs .
Additionally , there is some evidence that cluster radio galaxies become more centrally concentrated than CRS galaxies with cosmic time .
Within this same projected radius , we identify 7 spectroscopically-confirmed cluster XPSs , all with CRS host galaxy colors .
Consistent with the results from Martini et al .
( 2009 ) , we estimate a minimum X-ray active fraction of 1.4 \pm 0.8 % for CRS galaxies in high- z clusters , corresponding to an approximate 10-fold increase from 0.15 \pm 0.15 % at low- z .
Although complete redshift information is lacking for several XPSs in z > 0.4 cluster fields , the increased numbers and luminosities of the CRS radio galaxies and XPSs suggest a substantial ( 9-10 fold ) increase in the heat injected into high redshift clusters by AGN compared to the present epoch .