We derived O , Ne , and Mg abundances in the interstellar medium ( ISM ) of a relatively isolated S0 galaxy , NGC 4382 , observed with the Suzaku XIS instruments and compared the O/Ne/Mg/Fe abundance pattern to those of the ISM in elliptical galaxies .
The derived temperature and Fe abundance in the ISM are about 0.3 keV and 0.6–2.9 solar , respectively .
The abundance ratios are derived with a better accuracy than the abundances themselves : O/Fe , Ne/Fe , and Mg/Fe ratios are 0.3 , 0.7 , and 0.6 , respectively , in solar units .
The O/Fe ratio is smaller than that of the ISM in elliptical galaxies , NGC 720 , NGC 1399 , NGC 1404 , and NGC 4636 , observed with Suzaku .
Since O , Ne , and Mg are predominantly synthesized by supernovae ( SNe ) of type II , the observed abundance pattern indicates that the contribution of SN Ia products is higher in the S0 galaxy than in the elliptical galaxies .
Since the hot ISM in early-type galaxies is an accumulation of stellar mass and SN Ia products , the low O/Fe ratio in the ISM of NGC 4382 reflects a higher rate of present SNe Ia , or stars containing more SN Ia products than those in elliptical galaxies .