Modeling the broadband persistent emission of magnetars

TL;DR

This paper introduces a new Monte Carlo 3-D radiative model to simulate the broadband persistent emission of magnetars, accounting for relativistic effects, polarization, and QED phenomena, to better understand their X-ray spectra.

Contribution

The paper presents a novel self-consistent physical model for magnetar emission using advanced Monte Carlo simulations in the ultra-magnetized regime.

Findings

Predicted spectral properties in 0.1-1000 keV range

Polarization characteristics of magnetar emission

Application to observed magnetar spectra

Abstract

In this paper, we discuss our first attempts to model the broadband persistent emission of magnetars within a self consistent, physical scenario. We present the predictions of a synthetic model that we calculated with a new Monte Carlo 3-D radiative code. The basic idea is that soft thermal photons (e.g. emitted by the star surface) can experience resonant cyclotron upscattering by a population of relativistic electrons threated in the twisted magnetosphere. Our code is specifically tailored to work in the ultra-magnetized regime; polarization and QED effects are consistently accounted for, as well different configurations for the magnetosphere. We discuss the predicted spectral properties in the 0.1-1000 keV range, the polarization properties, and we present the model application to a sample of magnetars soft X-ray spectra.