摘要：Recent improvements in the age dating of stellar populations and single stars allow us to
study the ages and abundance of stars and galaxies with unprecedented accuracy. We here
compare the relation between age and α-element abundances for stars in the solar
neighborhood to that of local, early-type galaxies. We find these two relations to be very
similar. Both fall into two regimes with a shallow slope for ages younger than
~9 Gyr and a steeper
slope for ages older than that value. This quantitative similarity seems surprising
because of the different types of galaxies and scales involved. For the sample of
early-type galaxies we also show that the data are inconsistent with literature delay-time
distributions of either single- or double-Gaussian shape. The data are consistent with a
power-law delay-time distribution. We thus confirm that the delay-time distribution
inferred for the Milky Way from chemical evolution arguments must also apply to massive
early-type galaxies. We also offer a tentative explanation for the seeming universality of
the age-[α/Fe] relation: it is the manifestation of averaging
different stellar populations with varying chemical evolution histories.
关键词：stars: abundances;galaxies: abundances;galaxies: elliptical and lenticular, cD;supernovae: general;Galaxy: evolution
