Three-dimensional morphological asymmetries in the ejecta of Cassiopeia A using a component separation method in X-rays

Vol. 646
6. Instersellar and circumstellar matter

Three-dimensional morphological asymmetries in the ejecta of Cassiopeia A using a component separation method in X-rays

Models of the ejecta of core collapse supernovae produce inhomogeneous chemical mixing. This is very cleverly exploited in this study to derive the dynamical and spatial structure of the archetypical galactic supernova remnant Cas A. Despite the relatively low resolution of the Chandra ACIS spectral datacube (approximately 100), the authors use a novel component decomposition method to reconstruct the Doppler-shifted contributions to the individual line profiles of seven heavy elements. The blue- to redshifted separation yields asymmetrically expanding ejecta, with the redshifted structure moving in the opposite direction of the known remnant neutron star. The ejecta are dynamically and spatially concentrated in two principal structures, with the redshifted component coinciding with previously studied 44Ti emission. The study is a harbinger of things to come for future high spectral resolution imagers.