2019ApJ...873...53A

We present an archival Chandra study of the O-rich supernova remnant (SNR) 1E 0102.2-7219 in the Small Magellanic Cloud. Based on deep ∼265 ks archival Chandra data, we performed a detailed spatially resolved spectral analysis of 1E 0102.2-7219. Our aim is to reveal the spatial and chemical structures of this remnant in unprecedented detail. Radial profiles of O, Ne, and Mg abundances based on our analysis of regional spectra extracted along nine different azimuthal directions of 1E 0102.2-7219 suggest the contact discontinuity at ∼5.5 pc from the geometric center of the X-ray emission of the SNR. We find that the metal-rich ejecta gas extends further outward to the west and southwest than in the other directions of the SNR. The average O/Ne, O/Mg, and Ne/Mg abundance ratios of the ejecta are in plausible agreement with the nucleosynthesis products from the explosion of a ∼40 M_☉ progenitor. We estimate an upper limit on the Sedov age of ∼3500 yr and explosion energy of ∼1.8 x 10⁵¹ erg for 1E 0102.2-7219. We discuss the implications of our results for the geometrical structure of the remnant, its circumstellar medium and the nature of the progenitor star. Our results do not fit with a simple picture of the reverse-shocked emission from a spherical shell-like ejecta gas with a uniformly distributed metal abundance and a power-law density along the radius of the SNR.