We present the analysis of new X-ray observations of two Galactic radio supernova remnants ( SNRs ) , G337.2 - 0.7 and G309.2 - 0.6 .
Both remnants exhibit line-rich thermal spectra that require highly non-solar elemental abundance ratios .
In each case , Si and S are unequivocally overabundant compared to solar based purely on the measured equivalent width of the K \alpha line complex .
Detailed nonequilibrium ionization spectral analysis of these remnants , using a single temperature , single ionization age model , confirm the overabundances , yielding Si , S and Ar abundances many times their solar values : 3 to 5 times solar for G337.2 - 0.7 and greater than 3 to 10 times solar for G309.2 - 0.6 .
We also find that for both remnants , Ne and Mg are underabundant relative to Si , and for G309.2 - 0.6 , Ca and Fe as well are relatively underabundant .
This is the first detection of metal-rich , non-solar abundance material in these remnants , identifying them as young ejecta-dominated SNRs .
Further support for their youth comes from the distances that we estimate from the fitted column densities ( less than 15 kpc for G337.2 - 0.7 , and 4 \pm 2 kpc for G309.2 - 0.6 ) .
From the implied sizes of the remnants at these distances we infer relatively young ages ( 2000 to 4500 years for G337.2 - 0.7 , and 700 to 4000 years for G309.2 - 0.6 ) .
Finally we note that no compact object has yet been found within G337.2 - 0.7 , but an X-ray point source is evident within the radio shell of G309.2 - 0.6 , although its nature remains unknown .