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J. R. Dickel (Astronomy Dept., U. Illinois at Urbana-Champaign)
Supernova remnants release about 1051 ergs of mechanical energy into the circumstellar and interstellar medium. The expanding material slows as it sweeps up surrounding matter and amplifies any irregularities in its environs. Optical spectroscopy can be used to measure velocities and densities of the accumulated gas. Because the expansion is highly supersonic, shock waves quickly form. These shocks heat the gas to millions of kelvins producing bright thermal X-rays in both lines and the continuum. In turn, a major source of cooling of SNRs is in infrared spectral lines of excited ions. Surrounding dust can also be heated by the hot gas to produce infrared continuum emission. The strong shocks accelerate electrons to relativistic speeds, resulting in radio synchrotron emission. Rayleigh-Taylor instabilities at the interface of the ejected and swept-up material can further amplify the magnetic fields and particle energies to enhance the synchrotron radiation. Combination of multi-wavelength results is needed to fully characterize the energy budgets of supernova remnants.
Core collapse supernovae from massive stars also leave a compact central object, either a neutron star or a black hole. These objects can eject a variety of rings and jets. The spin-down energy of the compact object can excite the pulsar wind nebula that grows around it and it is often powerful enough to produce even X-ray synchrotron radiation.
The author(s) of this abstract have provided an email address for comments about the abstract: johnd@astro.uiuc.edu
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Bulletin of the American Astronomical Society, 34
© 2002. The American Astronomical Soceity.