Spatially Resolved Chandra Spectroscopy of the Large Magellanic Cloud Supernova Remnant N132D

Abstract

We perform detailed spectroscopy of the X-ray-brightest supernova remnant in the Large Magellanic Cloud (LMC), N132D, using Chandra archival observations. By analyzing the spectra of the entire well-defined rim, we determine the mean abundances for O, Ne, Mg, Si, S, and Fe for the local LMC environment. We find evidence of enhanced O on the northwestern and S on the northeastern blast wave. By analyzing spectra interior to the remnant, we confirm the presence of a Si-rich, relatively hot plasma (≳1.5 keV) that is also responsible for the Fe K emission. Chandra images show that the Fe K emission is distributed throughout the interior of the southern half of the remnant but does not extend out to the blast wave. We estimate the progenitor mass to be 15 ± 5 M⊙ using abundance ratios in different regions that collectively cover a large fraction of the remnant, as well as from the radius of the forward shock compared with models of an explosion in a cavity created by stellar winds. We fit ionizing and recombining plasma models to the Fe K emission and find that the current data cannot distinguish between the two, so the origin of the high-temperature plasma remains uncertain. Our analysis is consistent with N132D being the result of a core-collapse supernova in a cavity created by its intermediate-mass progenitor.