A Deep X-ray View of the Synchrotron-Dominated Supernova Remnant G330.2+1.0

TL;DR

This study uses deep XMM-Newton observations to analyze the nonthermal synchrotron emission of supernova remnant G330.2+1.0, revealing uniform spectral properties and high-energy electron acceleration indicative of a young, fast shock remnant.

Contribution

First detailed spectral analysis of the entire rim of G330.2+1.0 showing uniform nonthermal properties and high electron energies, confirming its young age and high shock velocity.

Findings

Spectral properties are consistent across the rim, with no significant variation.

Electron energies reach approximately 100 TeV, indicating efficient acceleration.

Remnant's age is likely young, with a shock velocity around 4600 km/s.

Abstract

We present moderately deep (125 ks) {\it XMM-Newton} observations of supernova remnant G330.2$+$1.0. This remnant is one of only a few known that fall into "synchrotron-dominated" category, with the emission almost entirely dominated by a nonthermal continuum. Previous X-ray observations could only characterize the spectra of a few regions. Here, we examine the spectra from fourteen regions surrounding the entire rim, finding that the spectral properties of the nonthermal emission do not vary significantly in any systematic way from one part of the forward shock to another, unlike several other remnants of this class. We confirm earlier findings that the power-law index, $\Gamma$, ranges from about 2.1-2.5, while the absorbing column density is generally between 2.0-2.6 $\times 10^{22}$ cm$^{-2}$. Fits with the {\it srcut} model find values of the roll-off frequency in the range of 10$^{17.1} - 10^{17.5}$ Hz, implying energies of accelerated electrons of $\sim 100$ TeV. These values imply a high shock velocity of $\sim 4600$ km s$^{-1}$, favoring a young age of the remnant. Diffuse emission from the interior is nonthermal in origin as well, and fits to these regions yield similar values to those along the rim, also implying a young age. Thermal emission is present in the east, and the spectrum is consistent with a $\sim 650$ km s$^{-1}$ shock wave encountering interstellar or circumstellar material with a density of $\sim 1$ cm$^{-3}$.