Spectropolarimetry of NGC3783 and Mrk509: Evidence for powerful nuclear winds in Seyfert 1 Galaxies

TL;DR

High-quality spectropolarimetric observations of Seyfert 1 galaxies NGC3783 and Mrk509 reveal complex polarized emission structures, including distinctive PA changes across Balmer lines, providing strong evidence for nuclear winds in these galaxies.

Contribution

This study presents detailed spectropolarimetric data and modeling that demonstrate the presence of nuclear winds in Seyfert 1 galaxies, a novel insight into their inner structures.

Findings

Detection of complex polarized emission structures.

Observation of 'M'-shaped PA profiles across Balmer lines.

Modeling supports the existence of nuclear winds.

Abstract

We present results from high signal-to-noise optical spectropolarimetric observations of the Seyfert 1 galaxies NGC783 and Mrk509 in the 3500-7000 A range. We find complex structure in the polarized emission for both objects. In particular, Position Angle (PA) changes across the Balmer lines show a distinctive 'M'-shaped profile that had not been observed in this detail before, but could represent a common trait in Seyfert 1 galaxies. In fact, while this shape is observed in all Balmer lines in NGC3783, Mrk509 transitions into a 'M'-shaped PA profile for higher transitions lines. We have modeled the observed profiles using the STOKES radiative transfer code and assuming that the scattering region is co-spatial with the BLR and outflowing. The results give compelling new evidence for the presence of nuclear winds in these two Seyfert 1 galaxies.