Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The role of massive stars in galactic chemical evolution   I will review the role of massive stars in galactic evolution both from the
nucleosynthesis and energetics point of view. In particular, I will highlight
some important observational facts explained by means of massive stars in
galaxies of different morphological type: the Milky Way, ellipticals and dwarf
spheroidals. I will describe first the time-delay model and its interpretation
in terms of abundance ratios in galaxies, then I will discuss the importance of
mass loss in massive stars to reproduce the data in the Galactic bulge and
disk. I will discuss also how massive stars can be important producers of
primary nitrogen if rotation in stellar models is taken into account.
Concerning elliptical galaxies, I will show that to reproduce the observed
[Mg/Fe] versus Mass relation in these galaxies it is necessary to assume a more
important role of massive stars in more massive galaxies and that this can be
achieved by means of downsizing in star formation. I will discuss how massive
stars are responsible in triggering galactic winds both in ellipticals and
dwarf spheroidals. These latter systems show a low overabundance of
alpha-elements relative to Fe with respect to Galactic stars of the same
[Fe/H]: this is interpreted as due to a slow star formation coupled with very
efficient galactic winds. Finally, I will show a comparison between the
predicted Type Ib/c rates in galaxies and the observed GRB rate and how we can
impose constraints on the mechanism of galaxy formation by studying the GRB
rate at high redshift.

13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin