Time Evolution of Gamma Rays from Supernova Remnants

TL;DR

This paper develops a numerical model to study the time evolution of multi-wavelength non-thermal emission from supernova remnants, focusing on particle acceleration, ambient medium effects, and implications for high-energy gamma-ray observations.

Contribution

It introduces a new numerical tool for modeling cosmic-ray spectrum evolution and emission in supernova remnants, considering different progenitor types and environmental factors.

Findings

Dense clumps cause spectral hardening in hadronic gamma rays.

The model predicts maximum particle energies and PeVatron phase duration.

Ambient medium significantly influences shock acceleration and emission.

Abstract

We present a systematic phenomenological study focused on the time evolution of the non-thermal radiation - from radio waves to gamma rays - emitted by typical supernova remnants via hadronic and leptonic mechanisms, for two classes of progenitors: thermonuclear and core-collapse. To this aim, we develop a numerical tool designed to model the evolution of the cosmic-ray spectrum inside a supernova remnant, and compute the associated multi-wavelength emission. We demonstrate the potential of this tool in the context of future population studies based on large collection of high-energy gamma-ray data. We discuss and explore the relevant parameter space involved in the problem, and focus in particular on their impact on the maximum energy of accelerated particles, in order to study the effectiveness and duration of the PeVatron phase. We outline the crucial role of the ambient medium through which the shock propagates during the remnant evolution. In particular, we point out the role of dense clumps in creating a significant hardening in the hadronic gamma-ray spectrum.