Relationship between AGNs and Environment. Deficiency of BLAGNs in Compact Groups

摘要

After analysis of the frequency and nature of nuclear activity in two samples of Compact Groups (CGs) of Galaxies we find a remarkable deficiency of Broad Line AGNs relative to Narrow Line AGNs, despite the high frequency of active nuclei found in these groups. The cause of the deficiency may be related to the typical compact group environment. The average low luminosity of AGNs (10~(39) erg s~(-1)) in CGs implies lower accretion rates resulting in Broad Line Regions (BLR) that are undetectable or absent.