Shocking features in the merging galaxy cluster RXJ0334.2−0111

• Published in: Monthly notices of the Royal Astronomical Society 2016-05, Vol.458 (1), p.681-694
• Main Authors: Dasadia, Sarthak, Sun, Ming, Morandi, Andrea, Sarazin, Craig, Clarke, Tracy, Nulsen, Paul, Massaro, Francesco, Roediger, Elke, Harris, Dan, Forman, Bill
• Format: Article
• Language: English
• Subjects: Borders; Cold fronts; Comparative analysis; Galactic clusters; Galaxies; Galaxy mergers & collisions; Mach number; Radio galaxies; Star & galaxy formation; X-ray astronomy; X-rays
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/stw291

We present a 66 ks Chandra X-ray observation of the galaxy cluster RXJ0334.2−0111. This deep observation revealed a unique bow shock system associated with a wide angle tail (WAT) radio galaxy and several intriguing substructures. The temperature across the bow shock jumps by a factor of ∼1.5 (from 4.1 to 6.2 keV), and is consistent with the Mach number M = 1.6 $_{-0.3}^{+0.5}$ . A second inner surface brightness edge is a cold front that marks the border between infalling subcluster cool core and the intracluster medium of the main cluster. The temperature across the cold front increases from 1.3 $_{-0.8}^{+0.3}$ to 6.2 $_{-0.6}^{+0.6}$  keV. We find an overpressurized region ∼250 kpc east of the cold front that is named ‘the eastern extension (EE)’. The EE may be a part of the third subcluster in the ongoing merger. We also find a tail shaped feature that originates near the bow shock and may extend up to a distance of ∼1 Mpc. This feature is also likely overpressurized. The luminous FR-I radio galaxy, 3C89, appears to be the cD galaxy of the infalling subcluster. We estimated 3C89's jet power from jet bending and the possible interaction between the X-ray gas and the radio lobes. A comparison between the shock stand-off distance and the Mach number for all known shock front/cold front combinations suggests that the core is continuously shrinking in size by stripping.