Linear spectropolarimetric analysis of fairall 9 with VLT/FORS2

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 Hβ and Hα 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. However, we suggest that the polarization properties appear to be more consistent with a warped disk geometry induced by Lense-Thirring precession.

Polarization in broad emission lines of active galactic nuclei

“…The observations confirm that there are influences of different geometries, for example, in several papers, the different polarized line profiles and PAs indicate different BLR geometries Jiang et al 2021), from outflows to the warped disc-like BLRs.…”

The main sequence of quasars: The taming of the extremes

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Polarimetric Reverberation Mapping in Medium-Band Filters

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