Monte Carlo Applications for Partially Polarized Inverse External-Compton Scattering (MAPPIES). I. Description of the Code and First Results

Abstract

The radiation mechanisms responsible for the multiwavelength emission from relativistic jet sources are poorly understood. The modeling of the spectral energy distributions and light curves alone is not adequate to distinguish between existing models. Polarization in the X-ray and γ-ray regime of these sources may provide new and unique information about the jet physics and radiation mechanisms. Several upcoming projects will be able to deliver polarimetric measurements of the brightest X-ray sources, including active galactic nuclei jets and γ-ray bursts. This article describes the development of a new Monte Carlo code—MAPPIES (Monte Carlo Applications for Partially Polarized Inverse External-Compton Scattering)—for polarization-dependent Compton scattering in relativistic jet sources. Generic results for Compton polarization in the Thomson and Klein–Nishina regimes are presented.

Radiation and Polarization Signatures from Magnetic Reconnection in Relativistic Jets. I. A Systematic Study

“…This is done through a Compton scattering module that works similarly as the 3DPol code, but without the polarization dependence. This is because the PD due to SSC and EC is generally very low in the blazar emission region, which is unlikely to be observed (Bonometto et al 1970;Paliya et al 2018;Zhang et al 2019;Dreyer & Böttcher 2021). To summarize, we consider two seed photon fields for the Compton scattering in the radiation transfer simulation: an inhomogeneous and fast-evolving synchrotron photon field for the SSC, and a uniform and stationary black body photon field for the EC.…”

New Simulations of the X-Ray Spectra and Polarizations of Accretion-disk Corona Systems with Various Geometrical Configurations I. Model Description

“…The corona plays a very important role in the disk-corona system. However, the evolution, formation heating and, especially, the geometrical configurations of the corona are still under debate, due to the complicated physical processes involved in the accretion system (e.g., see the discussions given by Dreyer & Böttcher 2021;You et al 2021;Ursini et al 2022). Various physical processes can lead to the formation of a corona and they show similar spectral profiles or spectral energy distributions (SEDs).…”

“…The geometrical configurations of these corona models are deeply connected with their physical origins. Thus, distinguishing the geometry of a corona from observable quantities will provide significant constraints on the physics of the accretion system (e.g., Dreyer & Böttcher 2021;Long et al 2022;Ursini et al 2022).…”

“…Comparing the time lags between the direct and reflected radiations (or radiations in different energy bands) can provide further constraints on the geometrical parameters of the disk-corona system (e.g., Ingram et al 2019;Mastroserio et al 2021). However, the polarization of X-ray radiations is an alternative and unique way to give possible new constraints on the corona geometry (Dreyer & Böttcher 2021;Long et al 2022;Ursini et al 2022;You et al 2021), since the polarizations induced by the inverse Comptonization are intrinsically dependent on the geometry and electron distribution (Schnittman & Krolik 2010;Laurent et al 2011;Beheshtipour et al 2017). The Compton scattering can be simply divided into Thomson and Klein-Nishina regimes according to the energy of incident photons and the cross sections are intrinsically polarization dependent (Fano 1949;Chandrasekhar 1960).…”

“…It can induce polarizations for anisotropic and unpolarized photons that scatter off non-relativistic electrons (Bonometto et al 1970;Schnittman & Krolik 2009). For photons scattering off energetic electrons, the polarization will be suppressed due to the beaming effect (e.g., Dreyer & Böttcher 2021). Thus the polarized radiations among the X-ray bands would be reasonably expected (Poutanen & Vilhu 1993;Schnittman & Krolik 2010;Beheshtipour et al 2017;Ursini et al 2022) and they can be used as a useful probe to distinguish the geometrical configurations of the corona-disk systems.…”