The chemical abundances of the Cassiopeia A fast-moving knots - Explosive nucleosynthesis on a minicomputer

Abstract

view Abstract Citations (4) References (26) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The chemical abundances of the Cassiopeia A fast-moving knots - Explosive nucleosynthesis on a minicomputer Johnston, M. D. ; Joss, P. C. Abstract A simplified nuclear reaction network for explosive nucleosynthesis calculations is described in which only the most abundant nuclear species and the most important reactions linking these species are considered. This scheme permits the exploration of many cases without excessive computational effort. Good agreement with previous calculations employing more complex reaction networks is obtained. This scheme is applied to the observed chemical abundances of the fast-moving knots in the supernova remnant Cassiopeia A and it is found that a wide range of initial conditions could yield the observed abundances. The abundances of four of the knots with significant and different amounts of elements heavier than oxygen are consistent with an origin in material of the same initial composition but processed at different peak temperatures and densities. Despite the observed high oxygen abundances and low abundances of light elements in the knots, they did not necessarily undergo incomplete oxygen burning; in fact, it is not even necessary that oxygen have been present in the initial composition. The agreement between the calculated and observed chemical abundances in Cas A and similar supernova remnants depends primarily upon the relevant nuclear physics and does not provide strong evidence in favor of any particular model of the supernova event. Publication: The Astrophysical Journal Pub Date: December 1980 DOI: 10.1086/158544 Bibcode: 1980ApJ...242.1124J Keywords: Abundance; Cassiopeia A; Minicomputers; Nuclear Fusion; Supernova Remnants; Astrophysics; Oxygen; Stellar Evolution; Astrophysics full text sources ADS |