Abstract
Here we present semi-analytical solutions of the hydrodynamics of compact supernova remnants (cSNRs) and their chemical evolution. Two models of 15 thickmuskip M[ scriptstyle sun ]and 25 thickmuskip M[ scriptstyle sun ]supernova explosions evolving in a high density medium ( n[0] ~ 10^7 thickmuskip cm-3) are throughly discussed. We demonstrate, that after a few years of evolution, diffusion leads to an homogeneous distribution of the SN products inside the cold, thin shell formed after cooling of the swept-up matter sets in. We find metallicity values within a range 5.5 thickmuskip <= Z[O]/Z[ scriptstyle sun ] <= thickmuskip 6.0 for M[SN] = 25 thickmuskip M[ scriptstyle sun ]and 1.0 thickmuskip <= Z[O]/Z[ scriptstyle sun ] <= thickmuskip 1.5 for M[SN] = 15 thickmuskip M[ scriptstyle sun ], and speculate wheather these metallicities could be related to the observed QSOs super solar elemental abundances (Ferland et al. 1996; Hamann & Ferland 1999).
