English

Cavities, shocks and a cold front around 3C 320

Astrophysics of Galaxies 2019-03-13 v1 High Energy Astrophysical Phenomena

Abstract

We present results obtained from the analysis of a total of 110 ks Chandra observations of 3C 320 FR II radio galaxy, located at the centre of a cluster of galaxies at a redshift z=0.342z=0.342. A pair of X-ray cavities have been detected at an average distance of \sim38 kpc along the East and West directions with the cavity energy, age and total power equal to \sim7.7×\times1059^{59} erg, \sim7×\times107^7 yr and \sim3.5×\times1044^{44} erg s1^{-1}, respectively. The cooling luminosity within the cooling radius of \sim100 kpc was found to be Lcool8.5×1043L_{cool} \sim8.5\times10^{43} erg s1^{-1}. Comparison of these two estimates implies that the cavity power is sufficiently high to balance the radiative loss. A pair of weak shocks have also been evidenced at distances of \sim47 kpc and \sim76 kpc surrounding the radio bubbles. Using the observed density jumps of \sim1.8 and \sim2.1 at shock locations along the East and West directions, we estimate the Mach numbers (M\mathcal{M}) to be \sim1.6 and \sim1.8, respectively. A sharp surface brightness edge was also detected at relatively larger radius (\sim80 kpc) along the South direction. Density jump at this surface brightness edge was estimated to be \sim1.6 and is probably due to the presence of a cold front in this cluster. The far-infrared luminosity yielded the star formation rate of 51 M_{\odot} yr1^{-1} and is 1/4th^{th} of the cooling rate (M˙\dot{M} \sim 192 M_{\odot} yr1^{-1}).

Keywords

Cite

@article{arxiv.1902.04778,
  title  = {Cavities, shocks and a cold front around 3C 320},
  author = {Nilkanth D. Vagshette and Sachindra Naik and Madhav. K. Patil},
  journal= {arXiv preprint arXiv:1902.04778},
  year   = {2019}
}

Comments

10 pages, 11 figures and 3 tables. Accepted for publication in MNRAS

R2 v1 2026-06-23T07:39:36.100Z