Linear Spectropolarimetric Analysis of Fairall 9 with VLT/FORS2

TL;DR

This study uses spectropolarimetric data of the quasar Fairall 9 to explore the geometry and dynamics of its broad emission line regions, revealing evidence of rotational motion and scattering effects.

Contribution

It provides new insights into the structure and kinematics of the broad line region in Fairall 9 using spectropolarimetric analysis, highlighting the role of scattering and rotation.

Findings

Evidence of rotational motion in the broad line region

Detection of polar and equatorial scatterers

Insights into non-virial motions in the emission lines

Abstract

The quasar Main Sequence (MS) appears to be an incredibly powerful tool to organize the diversity in large samples of type-1 quasars but the most important physical parameters governing it are still unclear. Here we investigate the origin of the broadening and of a defining feature of Population B sources: a strong redward asymmetry of the Balmer emission lines. We focus on a prototypical source, Fairall 9. Spectropolarimetric data of the Fairall 9 broad H$\beta$ and H$\alpha$ profiles allowed for a view of the geometric and dynamical complexity of the line emitting regions. Measurements (1) provided evidence of rotational motion; (2) were helpful to test the presence of polar and equatorial scatterers, and their association with non-virial motions.