The complex intracluster medium of Abell 1569 and its interaction with central radio galaxies

Abstract

We present the first in-depth study of X-ray emission from a nearby ($z\sim 0.0784$) galaxy cluster Abell 1569 using an archival $Chandra$ observation. A1569 consists of two unbound subclusters $-$ a northern subcluster (A1569N) hosting a double-lobed radio galaxy 1233+169 at its centre, and a southern subcluster (A1569S) harbouring a wide-angle-tailed (WAT) radio source 1233+168. X-ray emission from A1569N and A1569S extends to a radius $r\sim 248$ kpc and $r\sim 370$ kpc, respectively, indicating that the two gas clumps are group-scale systems. The two subclusters have low X-ray luminosities ($\sim 10^{42-43}$ erg s${}^{-1}$), average elemental abundances $\sim$1/4 Z${}_{\odot }$, low average temperatures ($\sim 2$ keV), and lack large ($r\gtrsim 40-50$ kpc) cool cores associated with the intracluster gas. We detect a pair of cavities coincident with the radio lobes of 1233+169 in A1569N. The total mechanical power associated with the cavity pair is an order of magnitude larger than the X-ray radiative loss in the cavity-occupied region, providing corroborating evidence for cavity-induced heating of the intragroup gas in A1569N. A1569S exhibits possible evidence for a small-scale cluster-subcluster merger, as indicated by its high central entropy, and the presence of local gas elongation and a density discontinuity in between the bent radio tails of 1233+168. The discontinuity is indicative of a weak merger shock with Mach Number, $M\sim 1.7$. The most plausible geometry for the ongoing interaction is a head-on merger occurring between A1569S and a subcluster falling in from the west along the line bisecting the WAT tails.

20 pages, 12 figures, 9 tables. Accepted for publication in the MNRAS

References in corpus (16)

• Heating Hot Atmospheres with Active Galactic Nuclei
• Shocks and cold fronts in galaxy clusters
• A Catalog of Galaxy Clusters Observed by XMM-Newton
• On the prevalence of radio-loud AGN in brightest cluster galaxies: implications for AGN heating of cooling flows
• Scaling Properties of a Complete X-ray Selected Galaxy Group Sample
• A statistically-selected Chandra sample of 20 galaxy clusters -- I. Temperature and cooling time profiles
• An XMM-Newton study of the environments, particle content and impact of low-power radio galaxies
• An Optical Catalog of Galaxy Clusters Obtained from an Adaptive Matched Filter Finder Applied to SDSS DR6
• Why Do Only Some Galaxy Clusters Have Cool Cores?
• Temperature and abundance profiles of hot gas in galaxy groups - I. Results and statistical analysis
• Shock heating of the merging galaxy cluster A521
• Giant cavities, cooling and metallicity substructure in Abell 2204
• The X-ray luminosity-temperature relation of a complete sample of low-mass galaxy clusters
• A Chandra study of Abell 795 -- a sloshing cluster with a FR0 radio galaxy at its center
• Low-scatter galaxy cluster mass proxies for the eROSITA all-sky survey
• The Hercules cluster in X-rays with $XMM$-$Newton$ and $Chandra$