Anne Bauer

Active galactic nuclei are extraordinarily complex systems with many interacting components, fueled by the gravitational potential energy of massive black holes. They are commonly seen to vary drastically in brightness over a large range of timescales and wavelengths. The causes of these fluctuations are currently unknown; however, details of the variability contain much information that can shed light on the physics at work in the systems.

The Palomar-QUEST Variability Survey has observed 15,000 square degrees of sky numerous times using optical filters over a span of 3.5 years. It is unique in its repeated coverage of such a large area, and is ideal for the study of rare variable objects such as AGN.

To understand the physics behind AGN optical emission, we have studied the variability of roughly 23,000 type I quasars and 1,000 blazars. We examined the quasar fluctuations in terms of timescale, optical luminosity, estimated black hole mass, X-ray loudness, radio loudness, and flare symmetry.

This is the first variability study of blazars involving such a large sample. We have determined common timescales of variability seen in the objects, and compared BL Lac and FSRQ subsets.

Blazars have typically been found by their strong X-ray and radio emission. They are very rare, and the full range of their properties is not yet known. In order to discover a set of blazars with selection biases different from those of previous samples, we have compiled a list of 3,955 highly optically variable objects seen in the Palomar-QUEST survey. The sample has been cleaned and characterized by color in order to maximize the likelihood of blazar discoveries. The large sky coverage of the Palomar-QUEST survey makes it possible for us to search for such rare objects by their variability, which has not been attempted before on this scale. The range of behavior seen in blazars selected in this unusual way will allow us to better understand the fundamental properties of these objects.