Star-formation quenching of cluster galaxies as traced by metallicity and presence of active galactic nuclei, and galactic conformity

Abstract

Aims. We strive to explore the differences in the properties and quenching processes of satellite galaxies in a sample of massive clusters with passive and star-forming (SF) brightest cluster galaxies (BCGs). One aim is to investigate galactic conformity effects, manifested in a correlation between the fraction of satellite galaxies that halted star formation and the state of star formation in the central galaxy. Methods. We explored 18 clusters from the Local Cluster Substructure Survey at 0.15â < 10.7) of the nine clusters with a passive BCG, with no metallicity enhancement seen for SF galaxies in clusters with active BCGs. Many of the SF galaxies with enhanced metallicities are found in the core regions of the phase-space diagram expected for virialized populations. We find a higher fraction of log(M/Mâ )âà  ¥10.7 SF galaxies at Râ