2003/06/05 by Una Hwang, J. M. Laming, J. Martin Laming · 1 citation
Physics and Astronomy · #Acis #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Cassiopeia A #Ejecta #Gamma-ray bursts and supernovae #Ion #Ionization #Physics #Solar and Space Plasma Dynamics #Solar mass #Stars #Supernova #Supernova remnant #astro-ph
paper · pdf · doi:10.1086/378269
published as Astrophys.J. 597 (2003) 362-373 · submitted to ApJ, companion to Laming & Hwang; 25 pages, 6 figures
arxiv created 2003/06/05 · openalex publication_date 2003/10/17 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We investigate the properties of Fe-rich knots on the east limb of the Cassiopeia A supernova remnant using observations with Chandra /ACIS and analysis methods developed in a companion paper. We use the fitted ionization age and electron temperature of the knots to constrain the ejecta density profile and the Lagrangian mass coordinates of the knots. Fe-rich knots that also have strong emission from Si, S, Ar, and Ca are clustered around mass coordinates q ≃ 0.35-0.4 in the shocked ejecta; for ejecta mass 2 M ☉ , this places the knots 0.7-0.8 M ☉ out from the center (or 2-2.1 M ☉ , allowing for a 1.3 M ☉ compact object). We also find an Fe clump that is evidently devoid of line emission from lower mass elements, as would be expected if it were the product of α-rich freezeout; the mass coordinate of this clump is similar to those of the other Fe knots.