AGN driven perturbations in the intra-cluster medium of cool core
  cluster ZwCl 2701
  We present the results obtained from a total of 123 ks X-ray (Chandra) and 8
hrs of 1.4 GHz radio (Giant Metrewave Radio Telescope - GMRT) observations of
the cool core cluster ZwCl 2701 (z = 0.214). These observations of ZwCl 2701
showed the presence of an extensive pair of ellipsoidal cavities along the East
and West directions within the central region < 20 kpc. Detection of bright
rims around the cavities suggested that the radio lobes displaced X-ray
emitting hot gas forming shell-like structures. The total cavity power
(mechanical power) that directly heated the surrounding gas and cooling
luminosity of the cluster were estimated to be ~2.27 x 10^{45} erg\s and 3.5 x
10^{44} erg\s, respectively. Comparable values of cavity power and cooling
luminosity of ZwCL 2701 suggested that the mechanical power of the AGN outburst
is large enough to balance the radiative cooling in the system. The star
formation rate derived from the H_alpha luminosity was found to be ~0.60 M_sun
yr^{-1} which is about three orders of magnitude lower than the cooling rate of
~196 M_sun yr^{-1}. Detection of the floor in entropy profile of ZwCl 2701
suggested the presence of an alternative heating mechanism at the centre of the
cluster. Lower value of the ratio (~10^{-2}) between black hole mass accretion
rate and Eddington mass accretion rate suggested that launching of jet from the
super massive black hole is efficient in ZwCl 2701. However, higher value of
ratio (~10^{3}) between black hole mass accretion rate and Bondi accretion rate
indicated that the accretion rate required to create cavities is well above the
Bondi accretion rate.
