Nonthermal Bremsstrahlung vs. Synchrotron Radiation: Cas A
Glenn Allen (MIT) , Stage, M. D. (U. of Mass, Amherst), Houck, J. C. (MIT)
We performed a joint spectral analysis of some Chandra and RXTE data for the supernova remnant Cas A. A 1.1 Ms ACIS data set is used to identify regions dominated by synchrotron radiation. The best-fit spectral models for each of these regions are combined to obtain a composite synchrotron model for the entire remnant. The difference between this model and the observed RXTE flux is fitted with a nonthermal bremsstrahlung model. The results of this analysis can be used to determine (1) the ratio of the synchrotron radiation to nonthermal bremsstrahlung in the RXTE energy band, (2) the shape of the electron spectrum at energies just above the thermal Maxwellian distribution, (3) the fraction of the electrons that are nonthermal and (4) the balance of energy between thermal and nonthermal electrons.