1 DSM/DAPNIA/SAp, CEA-Saclay, 91191 Gif sur Yvette Cedex FRANCE
2 Institut d'Astrophysique Spatiale, Orsay, France
Supernovae are key objects in the Universe. They are the factories where many of the heavy elements are made. The studies of the mass and composition of the ejecta is crucial for several astrophysical theories: stellar evolution, supernova explosions, galactic evolution, dust formation... We will present the results obtained from an homogeneous set of spectro-imaging (CVF) observations of the four youngest galactic supernova remnants: Cassiopeia-A (possibly a type Ib SN), Kepler SNR (possibly a type Ia), Tycho (type Ia) and the Crab Nebula (type II).
``Freshly'' synthetized supernova material has been observed. Of particular interest is the first convincing detection of Neon in Cassiopeia A. Another important result is the finding that part of the supernova material is condensed in the form of dust; the dust composition was derived from the observation of the silicate feature at 10 microns and from SWS follow-up observations at longer wavelengths. Information on the supernova explosion (incomplete degree of mixing) has even been deduced from the observations.
In addition, in the case of the Crab, unique information on the synchrotron Synchroton radiation was obtained.