Powerful AGN jets and unbalanced cooling in the hot atmosphere of IC
  4296
  We present new Karl G. Jansky Very Large Array (VLA, 1.5 GHz) radio data for
the giant elliptical galaxy IC 4296, supported by archival radio, X-ray
(Chandra, XMM-Newton) and optical (SOAR, HST) observations. The galaxy hosts
powerful radio jets piercing through the inner hot X-ray emitting atmosphere,
depositing most of the energy into the ambient intra-cluster medium (ICM).
Whereas the radio surface brightness of the A configuration image is consistent
with a Fanaroff-Riley Class I (FR I) system, the D configuration image shows
two bright, relative to the central region, large (~160 kpc diameter),
well-defined lobes, previously reported by Killeen et al., at a projected
distance r~>230 kpc. The XMM-Newton image reveals an X-ray cavity associated
with one of the radio lobes. The total enthalpy of the radio lobes is ~7x10^59
erg and the mechanical power output of the jets is ~10^44 erg/s. The jets are
mildly curved and possibly re-brightened by the relative motion of the galaxy
and the ICM. The lobes display sharp edges, suggesting the presence of bow
shocks, which would indicate that they are expanding supersonically. The
central entropy and cooling time of the X-ray gas are unusually low and the
nucleus hosts a warm H\alpha+[NII] nebula and a cold molecular CO disk. Because
most of the energy of the jets is deposited far from the nucleus, the
atmosphere of the galaxy continues to cool, apparently feeding the central
supermassive black hole and powering the jet activity.
