Investigating AGN feedback in α-luminous galaxy clusters: the first Chandra X-ray Analysis of Abell 2009

The ROSAT Brightest Cluster Sample (BCS) is a sample of 201 galaxy clusters from which a small sub-sample of 18 objects with X-ray fluxes greater than 9.0 x 10^-12 erg cm^-2 s^-1 and Halpha luminosities greater than 1.1 x 10^40 erg s^-1 was extracted in order to identify potentially strong cooling systems. This sample has been the subject of various studies in recent years and Abell 2009 is the only cluster still lacking a dedicated investigation. This Master thesis’ work presents a first X-ray analysis of the poorly studied cool-core galaxy cluster Abell 2009 (z \sim 0.152) based on archival Chandra (\sim 20ks) data. The morphological analysis has confirmed the cool-core nature of Abell 2009. By examining the residual image, four surface brightness depressions were visually identified and, based on their significance, we could not classify them as detected cavities. The morphological spiral shape of a brighter arm in the North-West direction suggests a sloshing phenomenon. The presence of this surface brightness discontinuity has been investigated, leading to a non-detectability. Through spectral analysis, it was possible to derive profiles of thermodynamical quantities of the ICM. These measurements were essential to derive the properties of the cooling region; specifically, we find a cooling radius of \sim 87.5 kpc. Furthermore, the cooling region has been analyzed, obtaining that radiative losses show a cooling luminosity of \sim 4.37 x 10^44 erg/s. In order to examine the hypothesis of the AGN feedback occurrence, we measured the work done to inflate the radio lobes in the ICM. The mechanical power is estimated to be \sim 1.12 x 10^45 erg/s, thus matching the magnitude of radiative cooling in the central regions. Finally, the analysis of Abell 2009 marks the conclusion of the X-ray analysis of the galaxy clusters from the original sample, allowing the investigation of relations describing the AGN feedback effects in galaxy clusters that we briefly discuss.