Dissecting the Main Sequence: AGN Activity and Bulge Growth in the Local Universe

• Published in: arXiv.org 2018-10
• Main Authors: McPartland, Conor, Sanders, David B, Kewley, Lisa J, Leslie, Sarah K
• Format: Article
• Language: English
• Subjects: Active galactic nuclei; Galactic bulge; Galactic evolution; Local group (astronomy); Seyfert galaxies; Sky surveys (astronomy); Star formation; Starburst galaxies; Stellar evolution; Universe
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1810.10021

Local galaxies from the Sloan Digital Sky Survey are used to provide additional support for an evolutionary pathway in which AGN activity is associated with star-formation quenching. Composite, Seyfert 2 and LINER galaxies account for \(\sim\)60\% of all star-formation in massive galaxies (\(M_\star > 10^{10.5} M_\odot\)). Inclusion of these galaxies results in a "turnover" in the \(SFR - M_\star\) relation for massive galaxies. Our analysis shows that bulge growth has already occurred in the most massive galaxies (\(M_\star > 10^{10.5}\) \(M_\odot\)), and bulges continue to grow as galaxies quench and redden, \((g-r)\) = 0.5 \(\rightarrow\) 0.75. Significant bulge growth is also occurring in low mass starburst galaxies (\(M_\star < 10^{10.5} M_\odot\)) at 0.5 dex above the "main sequence" (MS), where we find an increase in \(B/T\) from 0.1 \(\rightarrow\) 0.3 and bluer colours, \((g-r) < 0.25\) compared to low-mass galaxies on the MS.