Speaker
Description
Spectroscopic searches for Supermassive Black Hole Binaries (SMBHBs) aim to find quasars with broad emission lines whose velocity offsets show sinusoidal variation over periods of years to decades. This is thought to be an indicator of orbital motion in the case where one SMBH in the binary is actively accreting. One of the predominant limitations to this study is that single black hole quasars show Broad Line Region variability, and the extent of that variability has not been statistically characterized. In order to provide this characterization, we have developed a methodology for fitting variability in Sloan V spectra based on previous datasets. We fit a structure function to changes in the velocity of the centroid of broad $H\beta$ for all z<8 quasars with at least two SDSS I-IV spectra. The structure function provides characteristic variability amplitudes, as a function of the rest-frame time between observations, for all of the pairs of spectra in the sample. These amplitudes can be used to constrain the variability for normal quasars, improving the constraints available for spectroscopic searches for SMBHBs.
