PoS - Proceedings of Science
Volume 401 - High Energy Astrophysics in Southern Africa 2021 (HEASA2021) - Session: Active Galactic Nuclei
Optical Spectropolarimetry Observations of the BL Lac-type object PKS 0537-441 after a period of quiescence
J. Barnard*, B. van Soelen, J. Cooper, R. Britto, J.P. Marais, I. van der Westhuizen, D. Buckley, H. Schutte, M. Böttcher, B. Vaidya, S. Achariya and A. Martin-Carrillo
Full text: pdf
Pre-published on: December 20, 2021
Published on: May 30, 2022
Abstract
Blazars are a radio-loud subclass of active galactic nuclei with relativistic jets closely aligned with our line of sight. They are highly variable across all time-scales, and display rapid flares across multiple wavelength bands. At optical wavelengths, the observed emission is a superposition of non-thermal emission arising from the jet, and thermal emission that originates from the accretion disc, broad-line region, dust torus and host galaxy. Optical spectropolarimetry observations of blazars can be used to disentangle the thermal non-polarised and non-thermal polarised emission components in blazar emission during flaring and quiescent states. As part of a long-term monitoring campaign, spectropolarimetry observations have been taken with the Southern African Large Telescope of a selection of blazars during periods of increased activity. Here we focus on spectropolarimetry results and Fermi-LAT light curve of the BL-Lac type object PKS 0537-441 observed around a period of increased activity. It was observed to be active at both optical and gamma-ray energies after recovering from a faint state in late 2018. Spectropolarimetry observations were taken twice, with the degree of linear polarisation being between 35% and 40% during the first observation, and between 10% and 15% during the second, while there was no significant change in the strength of the emission line.
DOI: https://doi.org/10.22323/1.401.0009
How to cite

Metadata are provided both in "article" format (very similar to INSPIRE) as this helps creating very compact bibliographies which can be beneficial to authors and readers, and in "proceeding" format which is more detailed and complete.

Open Access
Creative Commons LicenseCopyright owned by the author(s) under the term of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.