Reverse and Forward Shock X-ray Emission in an Evolutionary Model of Supernova Remnants undergoing Efficient Diffusive Shock Acceleration

TL;DR

This paper develops comprehensive models for X-ray emission from supernova remnants, incorporating cosmic ray acceleration, non-equilibrium ionization, and hydrodynamics to better interpret future high-resolution X-ray observations.

Contribution

It introduces a self-consistent CR-hydro-NEI model that combines thermal and non-thermal emission processes, including Doppler broadening and shock effects, for detailed SNR spectral analysis.

Findings

Models predict X-ray spectra influenced by ambient environment and progenitor type.

Efficient cosmic ray acceleration significantly alters thermal emission features.

The approach aids interpretation of upcoming high-resolution X-ray data from Astro-H.

Abstract

We present new models for the forward and reverse shock thermal X-ray emission from core-collapse and Type Ia supernova remnants (SNRs) which include the efficient production of cosmic rays via non-linear diffusive shock acceleration (DSA). Our CR-hydro-NEI code takes into account non-equilibrium ionization (NEI), hydrodynamic effects of efficient CR production on the SNR evolution, and collisional temperature equilibration among heavy ions and electrons in both the shocked supernova (SN) ejecta and the shocked circumstellar material. While X-ray emission is emphasized here, our code self-consistently determines both thermal and non-thermal broadband emission from radio to TeV energies. We include Doppler broadening of the spectral lines by thermal motions of the ions and by the remnant expansion. We study, in general terms, the roles which the ambient environment, progenitor models, temperature equilibration, and processes related to DSA have on the thermal and non-thermal spectra. The study of X-ray line emission from young SNRs is a powerful tool for determining specific SN elemental contributions, and for providing critical information that helps to understand the type and energetics of the explosion, the composition of the ambient medium in which the SN exploded, and the ionization and dynamics of the hot plasma in the shocked SN ejecta and interstellar medium. With the approaching launch of the next-generation X-ray satellite Astro-H, observations of spectral lines with unprecedented high resolution will become a reality. Our self-consistent calculations of the X-ray spectra from various progenitors will help interpret future observations of SNRs.