Chandra Legacy Observation of the LMC SNR N132D: Expansion of the Forward Shock

Paul Plucinsky, Xi Long, Terrance Gaetz, Vinay Kashyap
2022 Zenodo  
We present results from a deep (900 ks) observation of the Large Magallenic Cloud supernova remnant N132D with the Chandra X-ray Observatory. N132D is an O-rich supernova remnant (SNR) of a 15-25 Mdot progenitor and is the most X-ray luminous SNR in the Local Group (L_x~1.0e38 ergs/s [0.3-10.0 keV]). The Chandra images reveal the spatial distribution of the elements Ne, Mg, Si, S, and Fe in unprecedented detail and a bright rim in the south where the shock is interacting with a molecular cloud
more » ... omplex. We have compared the images of the bright rim from a Chandra observation in 2006 to our new data to derive an expansion of 0.110 +/- 0.023 arcsec over the 14.5 yr baseline which corresponds to a shock velocity of 1850 +/- 386 km/s. We measure a shock velocity of 3435+/-374 km/s for a feature in an apparent blowout region in the north-east and use this value to estimate the deceleration of the shock wave in the molecular cloud interaction region. Spectral fits to narrow regions near the shock front result in an electron temperature of T_e~1.00 keV assuming a non-equilibrium ionization model with abundances typical of the interstellar medium in the LMC. This electron temperature implies a shock velocity of ~855 km/s assuming full electron-ion equilibration. We explore whether this apparent discrepancy between the electron temperature inferred from the measured shock velocity and that inferred from the spectral fits may be explained by cooling from Coulomb collisions and adiabatic expansion within the spectral extraction region.
doi:10.5281/zenodo.7294582 fatcat:nnhqafgvrbhuhhmjmyuw44lpfm