X-ray spectra from magnetar candidates - III. Fitting SGRs/AXPs soft X-ray emission with non-relativistic Monte Carlo models

TL;DR

This paper applies a 3D Monte Carlo spectral model based on the twisted magnetosphere scenario to fit X-ray observations of SGRs and AXPs, demonstrating good agreement with observed spectra.

Contribution

It introduces a systematic application of a non-relativistic Monte Carlo spectral model to observational data of magnetar candidates, validating the model's effectiveness.

Findings

Synthetic spectra fit most observed data well

Model successfully explains persistent X-ray emission

Supports the twisted magnetosphere scenario

Abstract

Within the magnetar scenario, the "twisted magnetosphere" model appears very promising in explaining the persistent X-ray emission from the Soft Gamma Repeaters and the Anomalous X-ray Pulsars (SGRs and AXPs). In the first two papers of the series, we have presented a 3D Monte Carlo code for solving radiation transport as soft, thermal photons emitted by the star surface are resonantly upscattered by the magnetospheric particles. A spectral model archive has been generated and implemented in XSPEC. Here we report on the systematic application of our spectral model to different XMM-Newton and Integral observations of SGRs and AXPs. We find that the synthetic spectra provide a very good fit to the data for the nearly all the source (and source states) we have analyzed.