Long-term evolution of non-thermal emission from Type Ia and core-collapse supernova remnants in a diversified circumstellar medium

TL;DR

This study models the long-term evolution of non-thermal emission from supernova remnants in different environments to understand cosmic ray origins and predict future observational insights.

Contribution

It provides a comprehensive hydrodynamic simulation of SNR evolution with diverse circumstellar environments, linking non-thermal emission to environmental and progenitor properties.

Findings

Non-thermal emission evolution varies significantly with environment.

CR re-acceleration and ion-neutral damping influence spectral changes.

Future X-ray observations can constrain SNR environmental and progenitor characteristics.

Abstract

The contribution of galactic supernova remnants (SNRs) to the origin of cosmic rays (CRs) is an important open question in modern astrophysics. Broadband non-thermal emission is a useful proxy for probing the energy budget and production history of CRs in SNRs. We conduct hydrodynamic simulations to model the long-term SNR evolution from explosion all the way to the radiative phase (or $3\times10^5$ yrs at maximum), and compute the time evolution of the broadband non-thermal spectrum to explore its potential applications on constraining the surrounding environments as well as the natures and mass-loss histories of the SNR progenitors. A parametric survey is performed on the ambient environments separated into two main groups, namely a homogeneous medium with a uniform gas density and one with the presence of a circumstellar structure created by the stellar wind of a massive red-supergiant (RSG) progenitor star. Our results reveal a highly diverse evolution history of the non-thermal emission closely correlated to the environmental characteristics of a SNR. Up to the radiative phase, the roles of CR re-acceleration and ion-neutral wave damping on the spectral evolution are investigated. Finally, we make an assessment of the future prospect of SNR observations by the next-generation hard X-ray space observatory FORCE and predict what we can learn from their comparison with our evolution models.