XRay

X-ray spectra and images of supernova remnants are being studied using imaging X-ray telescopes: NASA's CHANDRA observatory, ROSAT (NASA/ Germany/ UK X-ray telescope, in orbit 1990- 2000), and NASA's Einstein satellite (1978-1979). X-ray spectra of supernova remnants have studied using NASA's HEAO-1 satellite (1977-1979). Radio observations of supernova remnants using the Dominion Radio Astrophysical Observatory Synthesis Telescope and other ground based radio telescopes, such as the Bonn 100m telescope, are also being studied. The Infrared Astronomical Satellite (IRAS) data are analyzed in conjunction with the X-ray and radio data to study shocks and other physical processes in supernova remnants.

X-ray spectral and timing data of X-ray binary systems have been obtained by NASA?s CHANDRA and RXTE satellites, ROSAT and the Japanese satellites ASCA (1993-1998), GINGA (1987-90) and TENMA (1983-1985). Modeling of X-ray spectral changes as a function of orbital phase for both stellar wind accretors (GX301-2, 4U1907-09) and disk accretors (Her X-1) is being carried out to understand the accretion process. Observations of x-ray pulse shapes from neutron stars are being modeled to study the geometry of the emission regions on the neutron star surface. Iron-line emission from fluorescence in surrounding matter is studied through observations and also computer simulations to learn of the distribution and state of circumstellar matter.