Expected gamma-ray emission of supernova remnant SN 1987A

TL;DR

This paper uses nonlinear kinetic theory to model cosmic ray acceleration in SN 1987A, predicting magnetic field amplification, spectral features, and gamma-ray flux evolution over 100 years.

Contribution

It introduces a detailed nonlinear model of cosmic ray acceleration in SN 1987A, linking shock modification, magnetic field amplification, and multi-wavelength emission.

Findings

Magnetic field downstream of shock reaches ~20 mG.

Predicted TeV gamma-ray flux is about 4×10^{-13} erg cm^{-2}s^{-1}.

Nonthermal emission strength will roughly double in 15-20 years before declining.

Abstract

A nonlinear kinetic theory of cosmic ray (CR) acceleration in supernova remnants is employed to re-examine the nonthermal properties of the remnant of SN 1987A for an extended evolutionary period of 5--100 yr. It is shown that an efficient production of nuclear CRs leads to a strong modification of the outer supernova remnant shock and to a large downstream magnetic field $B_\mathrm{d}\approx 20$ mG. The shock modification and the strong field are required to yield the steep radio emission spectrum observed, as well as to considerable synchrotron cooling of high energy electrons which diminishes their X-ray synchrotron flux. These features are also consistent with the existing X-ray observations. The expected \gr energy flux at TeV-energies at the current epoch is nearly $\epsilon_{\gamma}F_{\gamma}\approx 4\times 10^{-13}$ erg cm$^2$s$^{-1}$ under reasonable assumptions about the overall magnetic field topology and the turbulent perturbations of this field. The general nonthermal strength of the source is expected to increase roughly by a factor of two over the next 15 to 20 yrs; thereafter it should decrease with time in a secular form.