Name: Jyoti Yadav
Affiliation: Indian Institute Of Astrophysics
Conference ID : ASI2022_309
Title : Discovery of triple active galactic nucleus in the NGC 7733-7734 merging group
Authors : Jyoti Yadav, Mousumi Das, Sudhanshu Barway and Francoise Combes
Abstract Type: Oral
Abstract Category : Extragalactic Astronomy
Abstract : Galaxy interactions and mergers are the major drivers of galaxy evolution in our low redshift universe, leading to the growth of supermassive black holes (SMBHs), bulges, and massive galaxies. Here, we present the study of interacting system NGC7733-34 using FUV (UVIT), NIR (IRSF) and MUSE (VLT) observations. We noticed an unusual emission along the northern arm of the NGC 7733 and further investigation with MUSE spectroscopic data led to the discovery of a new galaxy, NGC7733N. Galaxy interactions and mergers can lead to active galactic nucleus (AGN) pairs when the SMBHs start accreting mass. If there is a third galaxy involved in the interaction, then a triple-AGN system can form. Hence, we looked at the central regions of the galaxies in search of AGN activity. The emission line analysis showed presence of Seyfert (NGC7733 and NGC7733N) and LINER (NGC7734) typer AGNs making it a triple AGN system. Triple AGN are rare; however, their detailed studies could enhance their observed frequency in groups, and especially at high red-shift. Our study suggest that small merging groups are ideal laboratories for studying multiple-AGN systems. This study has been published in A&A Letters (doi.org/10.1051/0004-6361/202141210).