Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: To Ba or not to Ba: Enrichment in s-process elements in binary systems
  with WD companions of various masses   The enrichment in s-process elements of barium stars is known to be due to
pollution by mass transfer from a companion formerly on the thermally-pulsing
asymptotic giant branch (AGB), now a carbon-oxygen white-dwarf (WD). This paper
investigates the relationship between the s-process enrichment in the barium
star and the mass of its WD companion. It is expected that helium WDs, which
have masses smaller than about 0.5 Msun and never reached the AGB phase, should
not pollute with s-process elements their giant companion, which should thus
never turn into a barium star. Spectra with a resolution of R ~ 86000 were
obtained with the HERMES spectrograph on the 1.2-m Mercator telescope for a
sample of 11 binary systems involving WD companions of various masses. We use
standard 1D LTE MARCS model atmospheres coupled with the Turbospectrum
radiative-transfer code to derive the atmospheric parameters using equivalent
widths of FeI and Fe II lines. The abundances of s-process elements for the
entire sample of 11 binary stars were derived homogeneously. The sample
encompasses all levels of overabundances: from solar [s/Fe]=0 to 1.5 dex in the
2 binary systems with S-star primaries (for which dedicated MARCS model
atmospheres were used). The primary components of binary systems with a WD more
massive than 0.5 Msun are enriched in s-process elements. We also found a trend
of increasing [s/Fe] with [C/Fe] or [(C+N)/Fe]. Our results conform to the
expectation that binary systems with WD companions less massive than 0.5 Msun
do not host barium stars.

35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
4
The categories of this paper are: cond-mat
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas