Mon. Not. R. Astron. Soc., 461, 1885-1897 (2016/September-2)
AGN-driven perturbations in the intracluster medium of the cool-core cluster ZwCl 2701.
VAGSHETTE N.D., SONKAMBLE S.S., NAIK S. and PATIL M.K.
Abstract (from CDS):
We present the results obtained from a total of 123 ks X-ray (Chandra) and 8 h 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 1045 erg/s and 3.5 x 1044 erg/s , respectively. Comparable values of cavity power and cooling luminosity of ZwCl 2701 suggested that the mechanical power of the active galactic nuclei (AGN) outburst is large enough to balance the radiative cooling in the system. The star formation rate derived from the Hα luminosity was found to be ∼0.60 M☉/yr, which is about three orders of magnitude lower than the cooling rate of ∼196 M☉/yr. 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 (∼103) 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.