出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：A few topics concerning the early chemical evolution of the Milky Way are critically discussed.
In particular, it is argued that: 1) Observed abundance patterns of extremely metal-poor stars (of
Pop. II) do not constrain the mass range of the first generation (Pop. III) stars; the latter may
well be normal massive stars (10-50 M¯) or very massive ones (140-1000 M¯) or a combination
of the two classes. 2) The discrepancy between primordial Li abundance (after WMAP) and the
observed “Spite plateau” cannot be due to astration by a generation of massive Pop. III stars,
as recently suggested, unless such stars eject negligible amounts of metals. 3) The observed
halo metallicity distribution may well be understood in the framework of hierarchical galaxy
formation, as shown here with a simple semi-analytical model. 4) Formation of the Milky Way’s
halo from a myriad of smaller sub-haloes may have important implications for our understanding
of the abundance patterns of r-elements, the origin of which remains still unclear.
