We present new far-ultraviolet spectra of an oxygen-rich knot in the Large Magellanic Cloud supernova remnant N132D , obtained with the Hubble Space Telescope -Cosmic Origins Spectrograph .
Moderate resolution ( \Delta v \approx 200 km s ^ { -1 } ) spectra in the HST far-ultraviolet bandpass ( 1150 \lesssim \lambda \lesssim 1750 Å ) show emission from several ionization states of oxygen as well as trace amounts of other species .
We use the improvements in sensitivity and resolving power offered by COS to separate contributions from different velocity components within the remnant , as well as emission from different species within the oxygen-rich knot itself .
This is the first time that compositional and velocity structure in the ultraviolet emission lines from N132D has been resolved , and we use this to assess the chemical composition of the remnant .
No nitrogen is detected in N132D and multiple carbon species are found at velocities inconsistent with the main oxygen component .
We find helium and silicon to be associated with the oxygen-rich knot , and use the reddening-corrected line strengths of O iii ] , O iv ] , O v , and Si iv to constrain the composition and physical characteristics of this oxygen-rich knot .
We find that models with a silicon-to-oxygen abundance ratio of N ( Si ) / N ( O ) = 10 ^ { -2 } can reproduce the observed emission for a shock velocity of \approx 130 km s ^ { -1 } , implying a mass of \sim 50 M _ { \odot } for the N132D progenitor star .