Flux Variability of Gamma-Ray Blazars

Of the supermassive black holes found in the center of galaxies, blazars show the most extreme characteristics. Often the brightest objects in the gamma-ray sky, they show changes in flux on timescales from years down to minutes, challenging our models for high-energy emission. The Fermi Large Area Telescope has provided continuous coverage of the entire sky for over a decade, and from this rich data set we can construct light curves showing the gamma-ray flux of almost 30 blazar sources over many years. We apply a simple time series model to examine the properties of their flux variability, and use it to address the question of periodic flux variability in these remarkable sources.