Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Origin of Subdwarf B Star (I): the Formation Channels   Subdwarf B (sdB) stars (and related sdO/sdOB stars) are believed to be helium
core-burning objects with very thin hydrogen-rich envelopes. In recent years it
has become increasingly clear from observational surveys that a large fraction
of these objects are members of binary systems. To better understand their
formation, we here present the results of a detailed investigation of the three
main binary evolution channels that can lead to the formation of sdB stars: the
common envelope (CE) ejection channel, the stable Roche lobe overflow (RLOF)
channel and the double helium white dwarfs (WDs) merger channel. We obtained
the conditions for the formation of sdB stars from each of these channels using
detailed stellar and binary evolution calculations where we modelled the
detailed evolution of sdB stars and carried out simplified binary population
synthesis simulations. The observed period distribution of sdB stars in compact
binaries strongly constrains the CE ejection parameters. We also present the
distribution of sdB stars in the $T_{\rm eff}$ - $\log g$ diagram, the
Hertzsprung-Russell diagram and the distribution of mass functions.

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The categories of this paper are: nucl-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: patt-sol
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The categories of this paper are: q-bio
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The categories of this paper are: hep-lat
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The categories of this paper are: solv-int
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The categories of this paper are: hep-ex
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The categories of this paper are: funct-an
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The categories of this paper are: cs
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The categories of this paper are: supr-con
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The categories of this paper are: ao-sci
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The categories of this paper are: adap-org
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The categories of this paper are: acc-phys
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The categories of this paper are: math-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: nlin