Physical Properties of the Supernova Remnant Population in the Small Magellanic Cloud

TL;DR

This study analyzes the X-ray properties of 20 supernova remnants in the Small Magellanic Cloud to estimate their ages, energies, and surrounding medium densities using evolution models.

Contribution

It provides the first comprehensive analysis of SNRs in the SMC with measured temperatures and emission measures, deriving their physical parameters and birthrate.

Findings

Remnant birthrate of approximately 1/1200 years.

Energies and densities follow log-normal distributions.

Mean explosion energy of 1.6×10^{51} erg and mean density of 0.14 cm^{-3}.

Abstract

The X-ray emission from a supernova remnant is a powerful diagnostic of the state of its shocked plasma. The temperature and the emission measure are related to the energy of the explosion, the age of the remnant, and the density of the surrounding medium. Here we present the results of a study of the remnant population of the Small Magellanic Cloud. Progress in X-ray observations of remnants has resulted in a sample of 20 remnants in the Small Magellanic Clound with measured temperatures and emission measures. We apply spherically symmetric supernova remnant evolution models to this set of remnants, to estimate ages, explosion energies, and circumstellar medium densities. The distribution of ages yields a remnant birthrate of $\sim$1/1200 yr. The energies and densities are well fit with log-normal distributions, with means of 1.6$\times10^{51}$ erg and 0.14 cm$^{-3}$, and 1$\sigma$ dispersions of a factor of 1.87 in energy and 3.06 in density, respectively.