Spectroscopy of Broad Line Blazars from 1LAC

TL;DR

This study presents optical spectroscopy of 165 Fermi-detected Flat Spectrum Radio Quasars, revealing non-thermal emission characteristics, black hole mass estimates, and Eddington ratios, with implications for their orientation and emission mechanisms.

Contribution

It provides a nearly complete optical spectral analysis of Fermi FSRQs, highlighting non-thermal emission effects and biases in black hole mass estimates compared to optical quasars.

Findings

Fermi FSRQs exhibit significant non-thermal optical emission.

Black hole mass estimates are smaller due to viewing angle biases.

Fermi FSRQs have higher mean Eddington ratios than optical quasars.

Abstract

We report on optical spectroscopy of 165 Flat Spectrum Radio Quasars (FSRQs) in the Fermi 1LAC sample, which have helped allow a nearly complete study of this population. Fermi FSRQ show significant evidence for non-thermal emission even in the optical; the degree depends on the gamma-ray hardness. They also have smaller virial estimates of hole mass than the optical quasar sample. This appears to be largely due to a preferred (axial) view of the gamma-ray FSRQ and non-isotropic (H/R ~ 0.4) distribution of broad-line velocities. Even after correction for this bias, the Fermi FSRQ show higher mean Eddington ratios than the optical population. A comparison of optical spectral properties with Owens Valley Radio Observatory radio flare activity shows no strong correlation.