Modeling the Radio and X-ray Emission of SN 1993J and SN 2002ap

Modeling of radio and X-ray observations of supernovae interacting with their circumstellar media are discussed, with special application to SN 1993J and SN 2002ap. We emphasize the importance of including all relevant physical mechanisms, especially for the modeling of the radio light curves. The different conclusions for the absorption mechanism (free-free or synchrotron self-absorption), as well as departures from an $\rho \propto r^{-2}$ CSM, as inferred by some authors, are discussed in detail. We conclude that the evidence for a variation in the mass loss rate with time is very weak. The results regarding the efficiencies of magnetic field generation and relativistic particle acceleration are summarized.Comment: 10 pages, 2 figures. Uses svmult.cls. To appear in proceedings of IAU Colloquium 192 "Supernovae (10 years of SN 1993J)", April 2003, Valencia, Spain, eds. J. M. Marcaide and K. W. Weile

The Role of Radioactivities in Astrophysics

I present both a history of radioactivity in astrophysics and an introduction to the major applications of radioactive abundances to astronomy

Osse Observations Of Galactic Sources During Phase 1

The Oriented Scintillation Spectrometer Experiment (OSSE) on the COMPTON Gamma Ray Observatory has undertaken comprehensive observations of astrophysical sources during the eighteen-month Phase 1 of the mission. These include investigations of many galactic sources, including binary X-ray sources, pulsars, several transient X-ray sources observed as Targets-of-Opportunity, and Nova Cygni 1992. Multiple observations of the galactic center region were undertaken to map the diffuse galactic emission and search for point sources. An overview of the galactic source observations and some preliminary results are presented. INTRODUCTION During Phase 1 of the COMPTON Observatory mission, the OSSE instrument has been used to undertake observations of a variety of galactic sources. The OSSE instrument covers the energy range from 50 keV to 10 MeV when operated in nominal gain (see Johnson et al. 1 for a detailed description of the OSSE instrument). For several of the galactic source observations ..