X-Ray Emitting Ejecta of Supernova Remnant N132D

TL;DR

This paper reports the detection of substantial oxygen-rich ejecta in the supernova remnant N132D using X-ray observations, revealing spatial variations and a correlation with optical emission in a large expanding shell.

Contribution

First detection of significant oxygen-rich ejecta in N132D at X-ray wavelengths, linking optical and X-ray observations of the remnant's ejecta structure.

Findings

X-ray spectra dominated by oxygen emission lines

Spatial variations in ejecta absorption and emission

Optical and X-ray ejecta are spatially correlated in a large shell

Abstract

The brightest supernova remnant in the Magellanic Clouds, N132D, belongs to the rare class of oxygen-rich remnants, about a dozen objects that show optical emission from pure heavy-element ejecta. They originate in explosions of massive stars that produce large amounts of O, although only a tiny fraction of that O is found to emit at optical wavelengths. We report the detection of substantial amounts of O at X-ray wavelengths in a recent 100 ks Chandra ACIS observation of N132D. A comparison between subarcsecond-resolution Chandra and Hubble images reveals a good match between clumpy X-ray and optically emitting ejecta on large (but not small) scales. Ejecta spectra are dominated by strong lines of He- and H-like O; they exhibit substantial spatial variations partially caused by patchy absorption within the LMC. Because optical ejecta are concentrated in a 5 pc radius elliptical expanding shell, the detected ejecta X-ray emission also originates in this shell.