Structure And Orientation Of BLR In Quasars

Abstract

A comprehension of the geometry and kinematics of the BLR in quasars is essential to understand the role of quasars in galaxy evolution through accretion and feedback processes, as well as black hole growth. In particular, virial mass estimations depend upon the interpretation of the broad line region kinematics inferred through the emission line properties. We have analyzed the behavior of narrow and broad lines in a mutual framework as a means to investigate the morphology and kinematics in the inner regions of Active Galaxies (AGN). Assuming AGN structure follows the Unified Model, at least to first order, we have searched for connections between the spectroscopic emission coming from different AGN components, i.e., the NLR and BLR. I will discuss how the most prominent narrow line in the optical spectrum, [OIII], can be used to infer information about the BLR, regarding inclination and its physical structure. Information about orientation can shed light on both the ubiquity of the Unified Model as well as provide geometrical corrections to virial black hole mass estimations. Additionally, the connection between the characteristics of the narrow and broad emission can be used to investigate structural properties of the broad and narrow lines regions and how the different emission line regions contribute to a single- epoch emission line that samples all line-of-sight gas. With a specific focus on CIV, we use characteristics of [OIII] to disentangle emission components, some of which arises in regions where the gas velocities should not be contributing to the virialized velocity measurement for black hole masses, which can thus improve the accuracy of mass estimates.