The active CGCG 077-102 NED02 galaxy within the Abell 2063 galaxy cluster

TL;DR

This study confirms the presence of an active supermassive black hole in the galaxy CGCG 077-102 NED02 within Abell 2063, using multi-wavelength data to analyze its X-ray and optical variability and spectral features.

Contribution

First detection of active galactic nucleus activity in CGCG 077-102 NED02 through combined X-ray and optical observations, linking black hole activity to galaxy dynamics within a cluster.

Findings

Detected significant X-ray variability over days to years.

Optical spectroscopy indicates Seyfert activity in NED02.

Estimated black hole mass is approximately 10^6 solar masses.

Abstract

Within the framework of investigating the link between central super massive black holes in the core of galaxies and the galaxies themselves, we detected a variable X-ray source in the center of CGCG 077-102 NED02, member of the CGCG 077-102 galaxy pair within the Abell 2063 galaxy cluster. Our goal was then to combine X-ray and optical data to demonstrate that this object harbors an active super massive black hole in its core, and to relate this to the dynamical status of the galaxy pair within the Abell 2063 cluster. We used Chandra and XMM-Newton archival data to derive the X-ray spectral shape and variability. We also obtained optical spectroscopy to detect the expected emission lines that are typically found in Active Galactic Nuclei. And we finally used public ZTF imaging data to investigate the optical variability. There is no evidence of multiple X-ray sources or extended component within CGCG 077-102 NED02. Single X-ray spectral models fit well the source. Non-random significant X-ray flux inter-observation X-ray variabilities were detected, between ~4days for short term variations and up to ~700days for long term variations. Optical spectroscopy points toward a passive galaxy for CGCG 077-102 NED01 and a Seyfert for CGCG 077-102 NED02. We did not detect short-term variability in the optical ZTF light curves. However, we found a significant long-term stochastic variability in the g-band that can be well described by the damped random walk model. Finally, the CGCG 077-102 galaxy pair is deeply embedded within the Abell 2063 potential, and has underwent the cluster influence for a long time. Our observations point toward a moderatly massive black hole in the center of CGCG 077-102 NED02, of ~10^6 Msol. CGCG 077-102 NED02 is not heavily obscured, perhaps due to surrounding intra cluster medium ram pressure stripping.