Distinguishing Active Galactic Nuclei and Star Formation
Abstract
Using the large emission-line galaxy sample from the Sloan Digital Sky Survey we show that star-forming galaxies, Seyferts, and low ionization nuclear emission-line regions (LINERs) form clearly separated branches on the standard optical diagnostic diagrams. We derive a new empirical classification scheme that cleanly separates these emission-line galaxies, using strong optical emission lines. Using this classification, we identify a few distinguishing host galaxy properties in each class, which, along with the emission-line analysis, suggest continuous evolution from one class to another. As a final note, we introduce models of both star-forming galaxies and AGN narrow-line regions that can explain the distribution of galaxies on standard emission-line ratio diagrams and possibly suggest new diagnostics across the emission spectrum.
- Publication:
-
Pathways Through an Eclectic Universe
- Pub Date:
- June 2008
- DOI:
- 10.48550/arXiv.0707.0158
- arXiv:
- arXiv:0707.0158
- Bibcode:
- 2008ASPC..390..283G
- Keywords:
-
- Astrophysics
- E-Print:
- 4 pages, To Appear in Pathways through an eclectic Universe, J. H. Knapen, T. J. Mahoney, and A. Vazdekis (Eds.), ASP Conf. Ser., 2007