A DECADE-BASELINE STUDY OF THE PLASMA STATES OF EJECTA KNOTS IN CASSIOPEIA A

A DECADE-BASELINE STUDY OF THE PLASMA STATES OF EJECTA KNOTS IN CASSIOPEIA A

We present the analysis of 21 bright X-ray knots in the Cassiopeia A supernova remnant from observations spanning 10 yr. We performed a comprehensive set of measurements to reveal the kinematic and thermal state of the plasma in each knot, using a combined analysis of two high energy resolution High...

Full description

Bibliographic Details
Main Authors: Dewey, Dan (Contributor), Figueroa-Feliciano, Enectali (Contributor), Bastien, Fabienne A. (Contributor), Sato, Kosuke (Contributor), Rutherford, John Morton (Contributor), Heine, Sarah Nicole Trowbridge (Contributor), Canizares, Claude R. (Contributor)
Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor), MIT Kavli Institute for Astrophysics and Space Research (Contributor)
Format: Article
Language:English
Published: IOP Publishing, 2014-03-21T18:09:40Z.
Subjects:
Article
Online Access:Get fulltext
Description
Summary:We present the analysis of 21 bright X-ray knots in the Cassiopeia A supernova remnant from observations spanning 10 yr. We performed a comprehensive set of measurements to reveal the kinematic and thermal state of the plasma in each knot, using a combined analysis of two high energy resolution High Energy Transmission Grating (HETG) and four medium energy resolution Advanced CCD Imaging Spectrometer (ACIS) sets of spectra. The ACIS electron temperature estimates agree with the HETG-derived values for approximately half of the knots studied, yielding one of the first comparisons between high resolution temperature estimates and ACIS-derived temperatures. We did not observe the expected spectral evolution-predicted from the ionization age and density estimates for each knot-in all but three of the knots studied. The incompatibility of these measurements with our assumptions has led us to propose a dissociated ejecta model, with the metals unmixed inside the knots, which could place strong constraints on supernova mixing models.
United States. National Aeronautics and Space Administration (Award NNX10AE25G)
National Science Foundation (U.S.) (Partnerships in Astronomy & Astrophysics Research and Education Grant AST-0849736)
United States. National Aeronautics and Space Administration (Earth and Space Science Fellowship)
United States. National Aeronautics and Space Administration (Harriet Jenkins Predoctoral Fellowship Program)
Vanderbilt University (Provost Graduate Fellowship)

Similar Items