Modeling of the spatially resolved non-thermal emission from the Vela Jr. supernova remnant

TL;DR

This paper develops a self-consistent model of Vela Jr. supernova remnant's broadband emission and spatial intensity distribution, using particle transport and hydrodynamic simulations, to understand its non-thermal emission mechanisms.

Contribution

It introduces a combined particle transport and hydrodynamic simulation approach to model Vela Jr.'s emission and tests magnetic field configurations, revealing the importance of emission geometry.

Findings

Neither magnetic field model fully explains the radial X-ray spectrum dependence.

Spectral softening and intensity profiles can be explained with emission enhancement within a cone.

The model highlights the limitations of spherical symmetry assumptions in SNR emission modeling.

Abstract

Vela Jr. (RX J0852.0$-$4622) is one of just a few known supernova remnants (SNRs) with a resolved shell across the whole electromagnetic spectrum from radio to very-high-energy ($>100$ GeV; VHE) gamma-rays. Its proximity and large size allow for detailed spatially resolved observations of the source making Vela Jr. one of the primary sources used for the study of particle acceleration and emission mechanisms in SNRs. High-resolution X-ray observations reveal a steepening of the spectrum toward the interior of the remnant. In this study we aim for a self-consistent radiation model of Vela Jr. which at the same time would explain the broadband emission from the source and its intensity distribution. We solve the full particle transport equation combined with the high-resolution 1D hydrodynamic simulations (using Pluto code) and subsequently calculate the radiation from the remnant. The equations are solved in the test particle regime. We test two models for the magnetic field profile downstream of the shock: damped magnetic field which accounts for the damping of strong magnetic turbulence downstream, and transported magnetic field. Neither of these scenarios can fully explain the observed radial dependence of the X-ray spectrum under spherical symmetry. We show, however, that the softening of the spectrum and the X-ray intensity profile can be explained under the assumption that the emission is enhanced within a cone.