A CR-hydro-NEI Model of Multi-wavelength Emission from the Vela Jr. Supernova Remnant (SNR RX J0852.0-4622)

TL;DR

This study models the Vela Jr. supernova remnant using hydrodynamics and particle acceleration simulations, concluding that its GeV-TeV emission is primarily leptonic, which enhances understanding of cosmic-ray origins and supernova physics.

Contribution

The paper presents a self-consistent hydrodynamic and non-linear DSA model of Vela Jr., constraining emission origins and advancing methods for analyzing SNR multi-wavelength data.

Findings

Leptonic origin of GeV-TeV emission in Vela Jr.

Thermal X-ray line emission constrains model parameters.

Model matches observed radial brightness and spectral variations.

Abstract

Based largely on energy budget considerations and the observed cosmic-ray (CR) ionic composition, supernova remnant (SNR) blast waves are the most likely sources of CR ions with energies at least up to the "knee" near 3 PeV. Shocks in young shell-type TeV-bright SNRs are surely producing TeV particles, but the emission could be dominated by ions producing neutral pion-decay emission or electrons producing inverse-Compton gamma-rays. Unambiguously identifying the GeV-TeV emission process in a particular SNR will not only help pin down the origin of CRs, it will add significantly to our understanding of the diffusive shock acceleration (DSA) mechanism and improve our understanding of supernovae and the impact SNRs have on the circumstellar medium. In this study, we investigate the Vela Jr. SNR, an example of TeV-bright non-thermal SNRs. We perform hydrodynamic simulations coupled with non-linear DSA and non-equilibrium ionization near the forward shock (FS) to confront currently available multi-wavelength data. We find, with an analysis similar to that used earlier for SNR RX J1713.7-3946, that self-consistently modeling the thermal X-ray line emission with the non-thermal continuum in our one-dimensional model strongly constrains the fitting parameters, and this leads convincingly to a leptonic origin for the GeV-TeV emission for Vela Jr. This conclusion is further supported by applying additional constraints from observation, including the radial brightness profiles of the SNR shell in TeV gamma-rays, and the spatial variation of the X-ray synchrotron spectral index. We will discuss implications of our models on future observations by the next-generation telescopes.