Deficiency of Broad Line AGNs in Compact Groups of Galaxies

TL;DR

This study reveals a significant scarcity of Broad Line AGNs in Compact Groups of Galaxies, suggesting lower accretion rates or absence of BLRs possibly due to environmental effects like tidal interactions.

Contribution

It provides new observational evidence of the deficiency of Broad Line AGNs in CGs and discusses potential environmental causes affecting AGN properties.

Findings

Fewer Broad Line AGNs in CGs compared to Narrow Line AGNs

AGN luminosity in CGs is around 10^39 erg s^-1

Environmental effects like tidal interactions may suppress BLR formation

Abstract

Based on a new survey of AGN activity in Compact Groups of Galaxies, we report a remarkable deficiency of Broad Line AGNs as compared to Narrow Line AGNs. The cause of such deficiency could be related to the average low luminosity of AGNs in CGs: $10^{39}$ erg s$^{-1}$. This result may imply lower accretion rates in CG AGNs, making Broad Line Regions (BLR) undetectable, or may indicate a genuine absence of BLRs. Both phenomena are consistent with gas stripping through tidal interaction and dry mergers.