Polarization observations of AGN jets: Past and future
Document Type
Article
Publication Date
1-1-2022
Abstract
The magnetic field is believed to play a critical role in the bulk acceleration and propagation of jets produced in active galactic nuclei (AGN). Polarization observations of AGN jets provide valuable information about their magnetic fields. As a result of radiative transfer, jet structure, and stratification, among other factors, it is not always straightforward to determine the magnetic field structures from observed polarization. We review these effects and their impact on polarization emission at a variety of wavelengths, including radio, optical, and ultraviolet wavelengths in this paper. It is also possible to study the magnetic field in the launching and acceleration regions of AGN jets by using very long baseline interferometry (VLBI), which occurs on a small physical scale. Due to the weak polarization of the jets in these regions, probing the magnetic field is generally difficult. However, recent VLBI observations have detected significant polarization and Faraday rotation in some nearby sources. We present the results of these observations as well as prospects for future observations. Additionally, we briefly discuss recently developed polarization calibration and imaging techniques for VLBI data, which enable more in-depth analysis of the magnetic field structure around supermassive black holes and in AGN jets. © 2022 by the authors.
Keywords
Accretion, Accretion disks, Black hole physics, Galaxies, Active, Galaxies, Jets, Magnetic fields, Polarization
Divisions
PHYSICS
Funders
Chinese Academy of Sciences,Korea Astronomy and Space Science Institute,Universiti Malaya [Grant No: GPF081-2020]
Publication Title
Galaxies
Volume
10
Issue
5
Publisher
MDPI