X-ray spectroscopy of supernova remnants

The new generation X-ray telescopes launched in 1999 ( Chandra and XMM-Newton) provide for the first time, good spatial and spectral resolution together, allowing to map emission lines of heavy elements in supernova remnants. In young supernova remnants this reflects nucleosynthesis in the progenitor, and gives access (in theory) to the absolute amounts of the main elements, as well as their radial and azimuthal repartition. With arcsecond resolution, Chandra is able to resolve the shocked gas in the radial direction in young supernova remnants. The radial profile of density and temperature between the forward and reverse shocks is directly related to the density-velocity profile after the explosion. Looking for modifications to the remnant's structure induced by cosmic ray acceleration is another area accessible to the modern X-ray telescopes. It should tell us whether a significant fraction of the kinetic energy is spent accelerating cosmic rays at the shock. The shocked region is then thinner and the shocked gas less hot.