Where was the Iron Synthesized in Cassiopeia A?
Una Hwang, J. Martin Laming
Abstract
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 which 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 2Msun, this places the knots 0.7-0.8 Msun out from the center (or 2-2.1 Msun, allowing for a 1.3 Msun 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 alpha-rich freeze out; the mass coordinate of this clump is similar to those of the other Fe knots.
Create a lesson
Related papers
On binary pulsars and the force of gravity
Davor Palle
Tidal torques. A critical review of some techniques
Michael Efroimsky, James G. Williams
Dynamics of a Spherical Accretion Shock with Neutrino Heating and Alpha-Particle Recombination
Rodrigo Fernández, Christopher Thompson
Asymptotically FRW black holes
J. T. Firouzjaee, Reza Mansouri
Reaction of Accretion Disks to Abrupt Mass Loss During Binary Black Hole Merger
Sean M. O'Neill, M. Coleman Miller, Tamara Bogdanovic et al.
A Gamma-Ray Burst/Pulsar for Cosmic-Ray Positrons with a Dark Matter-like Spectrum
Kunihito Ioka