Constraints on the optical polarization source in the luminous non-blazar quasar 3C 323.1 (PG 1545+210) from the photometric and polarimetric variability

Abstract

We examine the optical photometric and polarimetric variability of the luminous type 1 non-blazar quasar 3C 323.1 (PG 1545+210). Two optical spectro-polarimetric measurements taken during the periods 1996−98 and 2003 combined with a V -band imaging polarimetric measurement taken in 2002 reveal that (1) as noted in the literature, the polarization of 3C 323.1 is confined only to the continuum emission, that is, the emission from the broad line region is unpolarized; (2) the polarized flux spectra show evidence of a time-variable broad absorption feature in the wavelength range of the Balmer continuum and other recombination lines; (3) weak variability in the polarization position angle (P A) of ∼ 4 deg over a time-scale of 4−6 years is observed; and (4) the V-band total flux and the polarized flux show highly correlated variability over a time-scale of one year. Taking the above-mentioned photometric and polarimetric variability properties and the results from previous studies into consideration, we propose a geometrical model for the polarization source in 3C 323.1, in which an equatorial absorbing region and an axi-asymmetric equatorial electron-scattering region are assumed to be located between the accretion disc and the broad line region. The scattering/absorbing regions can perhaps be attributed to the accretion disc wind or flared disc surface, but further polarimetric monitoring observations for 3C 323.1 and other quasars with continuum-confined polarization are needed to probe the true physical origins of these regions.

Constraints on Lorentz invariance and CPT violation using optical photometry and polarimetry of active galaxies BL Lacertae and S5 B0716+714

“…Optical photometric and polarimetric variability, correlations between flux and color, and searches for intraband photometric time lags, have been studied extensively in the literature for AGN and BL Lacertae type objects [54,[78][79][80][81][82], including the specific, well known AGN sources we observed: BL Lacertae [83][84][85][86], and S5 B0716+714 [87][88][89][90][91][92][93][94][95]. Our analysis is restricted to testing SME models, but our photometric and polarimetric time series could be analyzed similarly in future work.…”

Multiple giant eruptions and X-ray emission in the recoiling AGN/LBV candidate SDSS1133

“…About 10% of broad line AGNs are known to show blue-shifted broad absorption line (BAL) features in the UV wavelengths due to line absorption by high velocity disk winds (e.g., Hall et al 2002). However, only a few examples of hydrogen Balmer BAL AGNs are known to date, because the disk winds are generally too low-density and too highlyionized to keep neutral hydrogen atoms populated in the n = 2 shell (e.g., Hall 2007;Zhang et al 2015;Kokubo 2017;Burke et al 2020a). Considering the intrinsic rarity of the Balmer BAL AGNs, it is unreasonable to assume that the P-Cygni features of SDSS1133 (selected as a rare offset AGN) are due to the Balmer BAL nature.…”

Accretion of dissipative dark matter onto active galactic nuclei

“…By losing angular momentum, this matter falls into the BH, feeding it, while at the same time releasing radiation to the surroundings. Although the accretion mechanism has been investigated for the past few decades (for an introduction and references, see for example [47][48][49][50]), accretion disks are not well understood [51][52][53][54][55]. In particular, a first principle understanding of the origin of the viscosity, necessary for angular momentum loss and consistent with maintaining a steady state disk, is still lacking [56][57][58].…”