Detailed X-Ray Mapping of the Shocked Ejecta and Circumstellar Medium in the Galactic Core-collapse Supernova Remnant G292.0+1.8

Abstract

Abstract G292.0+1.8 (G292) is a young (∼3000 yr), Galactic textbook-type core-collapse supernova remnant. It is characterized by X-ray, optical and infrared emission from ejecta and circumstellar medium (CSM) features, and contains a pulsar (PSR J1124-5916) and pulsar wind nebula that have been observed in X-rays and radio. Previous studies have revealed a complex, dynamically evolving, oxygen-rich remnant, a striking relic from the explosion of a massive star. Here, using our deep (530 ks) Chandra ACIS data, we present high spatial-resolution maps (based on a regional grid size of a few arcsecond) of the shocked CSM and metal-rich ejecta in G292. We make the first Chandra-detection of Fe-rich ejecta in G292. We identify the X-ray counterpart of the northern equatorial belt, a component of a ring-like CSM structure identified earlier in the infrared band. We show the detailed spatial distributions of ejecta enriched in O, Ne, Mg, Si, S, and Fe. We find that the bulk of the Si, S, and Fe-rich X-ray-emitting ejecta are located in the northwestern hemisphere of the remnant, opposite to the pulsar’s projected angular displacement to the southeast from the SNR’s center. This suggests that the pulsar’s kick may have originated from gravitational and hydrodynamic forces during an asymmetric explosion, rather than from anisotropic neutrino emission. Based on abundance ratios and our estimated CSM and ejecta masses, we constrain the progenitor mass to 13 M ⊙ ≲ M ≲ 30 M ⊙