[Previous] | [Session 112] | [Next]
E.V. Gotthelf (Columbia), B. Koralesky (Minnesota), U. Hwang, R. Petre (NASA/GSFC), T.W. Jones, L. Rudnick (Minnesota), S. Holt (NASA/GSFC)
We have identified a sharp X-ray bright boundary at the outer edge of the young supernova remnant Cassiopeia-A using data obtained with the Chandra Observatory. Energy selected maps restricted to the high energy X-ray continuum emission-band (4-6 keV) provides direct evidence for the supernova remnant's projected outer shock front. Thin wisps (< 0.1\prime wide) form a circular boundary, ~ 2.7\prime in radius, which is seen to encompass the bulk of the bright thermal X-ray and radio emission. This brightened edge is not evident in the X-ray line emission or the radio continuum data. VLA radio data shows large jumps in the synchrotron polarization angle along the rim, interior to which the inferred magnetic field is predominantly radial; we suggest these jumps arise from compression associated with an outer shock. We consider physical mechanisms for the observed structure.
\bigskip Acknowledgments: SNR research at the University of Minnesota is supported by the NASA Graduate Student Research Program and the National Science Foundation under grant AST 96-19438. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. E.V.G is supported by NASA LTSA grant NAG5-7935.
If you would like more information about this abstract, please follow the link to http://www.astro.columbia.edu/~evg. This link was provided by the author. When you follow it, you will leave the Web site for this meeting; to return, you should use the Back comand on your browser.
The author(s) of this abstract have provided an email address for comments about the abstract: evg@astro.columbia.edu