Hubble Space Telescope Proper Motion Measurements of Supernova Remnant N132D: Center of Expansion and Age

Abstract We present proper motion measurements of the oxygen-rich ejecta LMC supernova remnant N132D using two epochs Hubble Space Telescope Advanced Camera for Surveys data spanning 16 years. The motions 120 individual knots gas were measured and used to calculate a center expansion (CoE) α = 5 h 25 m 01.ˢ71 δ −69°38′41.″64 (J2000) with 1 σ uncertainty 2.″90. This new CoE measurement is 9.″2 10.″8 from previous estimates based on geometry optically emitting ejecta. also derive an explosion age 2770 ± 500 yr, which consistent recent ≈2500 yr made 3D reconstructions. verified our automated procedure that detected tracked 137 knots, 73 overlap visually identified knots. find are still ballistic, despite remnant’s age, notion expanding into interstellar medium cavity. Evidence asymmetry parent observed. Using corresponding we compare other remnants studies.