A High‐ResolutionROSATX‐Ray Study of Abell 4059

Publisher Website
Google Scholar
Abstract
We present the analysis of ROSAT HRI and PSPC X-ray data on the compact cD type cluster Abell 4059. The central cD galaxy hosts the strong radio source PKS 2354-35. The central portion of the X-ray image shows two statistically significant X-ray emission minima and an orthogonal X-ray bar. As is the case in NGC 1275, the radio lobes in PKS 2354-35 lie perpendicularly to the X-ray bar and extend into the two X-ray minima. One suggestion is that the radio lobe plasma has displaced the X-ray plasma and created the X-ray holes. The radio plasma and the X-ray gas do have comparable pressures in the radio lobe area. However, the available radio images do not show radio emission that extends far enough to fill the two X-ray holes. An alternative scenario for the anticorrelated radio and X-ray structure is an rotating disk in the cooling flow region of Abell 4059. The ROSAT HRI surface brightness profile shows that there is a cooling flow around the central cD galaxy with a cooling rate of =184+ 22−25 M☉ yr-1 within a radius of 156 kpc. However, the ROSAT PSPC spectrum of the central regions does not require a cooling flow and gives an upper limit to the cooling rate of < 80 M☉ yr-1 (90% confidence level). The X-ray spectra of the central region indicate very little intrinsic absorption in the cluster, with an upper limit of ΔNH ≤ 4.0 × 1019 cm-2 for excess absorption in front of the cluster emission at the center of the cooling flow. On large scales, the cluster shows interesting spatial alignment between the major axes of the X-ray emission, cD galaxy, and the cluster potential. This is consistent with the anisotropic merger model for the formation of cD galaxies and the orientation of cD galaxy radio sources.
All Related Versions

This publication has 29 references indexed in Scilit: