The contribution of non-central radio galaxies to AGN feedback in rich
  galaxy clusters
  We present a combined radio/X-ray study of six massive galaxy clusters, aimed
at determining the potential for heating of the intra-cluster medium (ICM) by
non-central radio galaxies. Since X-ray cavities associated with the radio
lobes of non-central galaxies are generally not detectable, we use Giant
Metrewave Radio Telescope 610~MHz observations to identify jet sources and
estimate their size, and Chandra data to estimate the pressure of the
surrounding ICM. In the radio, we detect 4.5% of galaxies above the
spectroscopic survey limit (M*K+2.0) of the Arizona cluster redshift survey
(ACReS) which covers five of our six clusters. Approximately one tenth of these
are extended radio sources. Using star formation (SF) rates determined from
mid-infrared data, we estimate the expected contribution to radio luminosity
from the stellar population of each galaxy, and find that most of the
unresolved or poorly-resolved radio sources are likely star formation
dominated. The relatively low frequency and good spatial resolution of our
radio data allows us to trace star formation emission down to galaxies of
stellar mass ~10^9.5 Msol. We estimate the enthalpy of the (AGN dominated)
jet/lobe and tailed sources, and place limits on the energy available from
unresolved radio jets. We find jet powers in the range ~10^43-10^46 erg/s,
comparable to those of brightest cluster galaxies. Our results suggest that
while cluster-central sources are the dominant factor balancing ICM cooling
over the long term, non-central sources may have a significant impact, and that
further investigation is possible and warranted.
