Schedule Feb 10, 2006
HETGS Observation of SNR Cas A: Looking at the trees in the forest
Lazendic, Dewey, Schulz, & Canizares

High resolution X-ray spectra extracted from 17 bright, narrow regions of Cas A provide unique insights into their kinematics and plasma state. From the dominant emission lines of H- and He-like silicon and sulfur we derive accurate Doppler shifts in the range -2500 to +4000 km/s which agree well with transverse-velocity measurements (DeLaney 2004.) Plasma diagnostics of these regions indicate temperatures largely of order 1 keV with some above 3 keV. Using as well the non-dispersed zeroth-order data, we determine NEI model parameters for the regions and consider them in the context of an O-rich reverse-shocked ejecta model (Laming & Hwang 2003.)

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