Ji-Jia Tang (Australian National University); Christian Wolf (Australian National University); John Tonry (University of Hawaii)
We aim at studying the accretion disk of active galactic nuclei (AGN) through quasar variability. We obtain ∼1200 quasars’ light curves of two filters, o- and c-bands, from Asteroid Terrestrial-impact Last Alert System (ATLAS) survey. The observing time span is about four years with a total of ∼900 thousands and ∼250 thousands of data points for o- and c-bands, respectively. We use the structure function (SF) to analyze the quasar variability and discover an empirical relation between the SF, the bolometric luminosity (Lbol), the rest-frame wavelength (λrest), and the time difference (∆t). This relation will reveal the temperature profile of the accretion disk, and allow us to examine predictions from various accretion disk models using quasar SFs.