摘要
在8000至8670的波长范围内,利用一个由144颗恒星光谱组成的光谱厍,我们对57个巨椭圆和S0星系(M_B<-21)的光谱和它们的平均光谱进行了光谱合成.这个光谐库包括了光谱型为G,K和M的巨星和矮星,它具有的金属丰度[Fe/H]覆盖了-0.1到-0.5的范围,表面重力log g为1.0至5.0.光谱合成的结果表明:巨椭圆和S0星系的金属丰度约为太阳的一倍半;有效表面重力分布在3.2—4.1的范围内;矮星在8400附近光的贡献可与巨星相比较.
Using a library of spectra of 144 stars observed in the range 8000-8670 A, we have made a population synthesis of mean and individual spectra of 57 giant E/SO galaxies (MB < -21). The library includes stars with spectral class from G to M, surface gravity log g from 1.0 to 5.0, with metallicity from -0.1 to 0.5. The results of population synthesis show that the giant E/SO galaxies have a mean metallicity about one and half the solar abundance, that the representative surface gravity varies from 3.2 to 4.1 and that the light contribution at 8400A from the dwarfs are comparable to that of the giants.
