Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Kinematics of Subluminous O and B Stars by Surface Helium Abundance   The majority of hot subdwarf stars are low-mass core-helium-burning stars.
Their atmospheres are generally helium deficient; however a minority have
extremely helium-rich surfaces. An additional fraction have an intermediate
surface-helium abundance, occasionally accompanied by peculiar abundances of
other elements. We have identified a sample of 88 hot subdwarfs including 38
helium-deficient, 27 intermediate-helium and 23 extreme-helium stars for which
radial-velocity and proper-motion measurements, together with distances, allow
a calculation of Galactic space velocities. We have investigated the kinematics
of these three groups to determine whether they belong to similar or different
galactic populations. The majority of helium-deficient subdwarfs in our sample
show a kinematic distribution similar to that of thick disk stars. Helium-rich
sdBs show a more diverse kinematic distribution. Although the majority are
probably disk stars, a minority show a much higher velocity dispersion
consistent with membership of a Galactic halo population. Several of the halo
subd- warfs are members of the class of "heavy-metal" subdwarfs discovered by
Naslim et al. (2011, 2013).

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The categories of this paper are: funct-an
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The categories of this paper are: hep-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: math
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The categories of this paper are: q-bio
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The categories of this paper are: supr-con
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The categories of this paper are: plasm-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: q-fin
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The categories of this paper are: comp-gas
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The categories of this paper are: bayes-an
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The categories of this paper are: math-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: quant-ph
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The categories of this paper are: physics
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The categories of this paper are: acc-phys