Estimating the masses of z > 2.5 quasars from accretion disk models

Black hole masses for z > 2 quasars are typically estimated from single-epoch spectroscopy using the monochromatic continuum luminosity at 1350 Å and the Civ 1549 Å line width. These masses exhibit large scatter (≈ 0.5 decades) from the true masses and are subject to large systematic errors due to the idiosyncrasies of the Civ line profile. As a result, in this thesis I estimate the masses of a sample of 86 z > 2.5 radio-loud quasars by fitting accretion disk models to the restframe ultraviolet quasar spectra. I also fit accretion disk models to a matched sample of 86 radio-quiet quasars, in order to both explore the differences between radio loud and radio quiet quasars and estimate the possible contribution from strong radio jets or synchrotron emission to the radio-loud quasar continuum. Finally, I explore the errors introduced by several different systematic effects and give a rough accounting of the total error budget of the mass estimates.