Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The metallicity dependence of WR winds   Wolf-Rayet (WR) stars are the most advanced stage in the evolution of the
most massive stars. The strong feedback provided by these objects and their
subsequent supernova (SN) explosions are decisive for a variety of
astrophysical topics such as the cosmic matter cycle. Consequently,
understanding the properties of WR stars and their evolution is indispensable.
A crucial but still not well known quantity determining the evolution of WR
stars is their mass-loss rate. Since the mass loss is predicted to increase
with metallicity, the feedback provided by these objects and their spectral
appearance are expected to be a function of the metal content of their host
galaxy. This has severe implications for the role of massive stars in general
and the exploration of low metallicity environments in particular. Hitherto,
the metallicity dependence of WR star winds was not well studied. In this
contribution, we review the results from our comprehensive spectral analyses of
WR stars in environments of different metallicities, ranging from slightly
super-solar to SMC-like metallicities. Based on these studies, we derived
empirical relations for the dependence of the WN mass-loss rates on the
metallicity and iron abundance, respectively.

29
The categories of this paper are: funct-an
16
The categories of this paper are: stat
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
13
The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th