Polarization of Compton X-rays from Jets in AGN

TL;DR

This study uses Monte Carlo simulations to analyze X-ray polarization from relativistic jets in AGN, showing how different scattering scenarios produce distinct polarization signatures that can help identify emission mechanisms.

Contribution

It introduces a detailed simulation framework for X-ray polarization in AGN jets, comparing multiple scattering scenarios to aid in understanding jet emission models.

Findings

Maximum polarization exceeds 20% for disk and CMB scattering at high viewing angles.

SSC can produce polarization over 80%, depending on photon injection sites.

Polarization patterns vary significantly with viewing angle and scattering scenario.

Abstract

We investigate the polarization of Compton scattered X-rays from relativistic jets in active galactic nuclei using Monte Carlo simulations. We consider three scenarios: scattering of photons from an accretion disk, scattering of cosmic microwave background (CMB) photons, and synchrotron self-Comptonization (SSC) within the jet. For Comptonization of thermal disk photons or CMB photons the maximum linear polarization attained is slightly over 20% at viewing angles close to 90 degrees. The value decreases with the viewing inclination. For SSC, the maximum value may exceed 80%. The angle dependence is complicated, and it varies with the photon injection sites. Our study demonstrates that X-ray polarization, in addition to multi-wavelength spectra, can distinguish certain models for emission and particle acceleration in relativistic jets.