Presentation #213.08 in the session AGN and Quasars III.
Low luminosity active galactic nuclei (LLAGN) are objects of great interest, as they can provide clues about galaxy evolution. AGN variability is ubiquitous and thus provides a reliable tool for finding AGN. In search of AGN, we analyze the All-Sky Automated Survey for SuperNovae (ASAS-SN) light curves of 1218 bright galaxies (g<14 mag) with Sloan Digital Sky Survey (SDSS) spectra. We use structure function to characterize variability and identify 37 targets to have AGN-like structure function, which is about 3% of the sample. Combining the BPT line ratio diagnostics and the broad line AGN, up to 60% of the AGN candidates are confirmed spectroscopically, while BPT diagnostics classified 10-30% of the candidates as star forming galaxies rather than AGN. In addition, we find that about 80% of our AGN candidates are LLAGN with the Eddington ratios ranging from 10-4 to 10-2, which allows us estimate the LLAGN fraction among galaxies.