Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: How Dry is the Brown Dwarf Desert?: Quantifying the Relative Number of
  Planets, Brown Dwarfs and Stellar Companions around Nearby Sun-like Stars   Sun-like stars have stellar, brown dwarf and planetary companions. To help
constrain their formation and migration scenarios, we analyse the close
companions (orbital period < 5 years) of nearby Sun-like stars. By using the
same sample to extract the relative numbers of stellar, brown dwarf and
planetary companions, we verify the existence of a very dry brown dwarf desert
and describe it quantitatively. With decreasing mass, the companion mass
function drops by almost two orders of magnitude from 1 M_Sun stellar
companions to the brown dwarf desert and then rises by more than an order of
magnitude from brown dwarfs to Jupiter-mass planets. The slopes of the
planetary and stellar companion mass functions are of opposite sign and are
incompatible at the 3 sigma level, thus yielding a brown dwarf desert. The
minimum number of companions per unit interval in log mass (the driest part of
the desert) is at M = 31^{+25}_{-18} M_Jup. Approximately 16% of Sun-like stars
have close (P < 5 years) companions more massive than Jupiter: 11% +- 3% are
stellar, <1% are brown dwarf and 5% +- 2% are giant planets. The steep decline
in the number of companions in the brown dwarf regime, compared to the initial
mass function of individual stars and free-floating brown dwarfs, suggests
either a different spectrum of gravitational fragmentation in the formation
environment or post-formation migratory processes disinclined to leave brown
dwarfs in close orbits.

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The categories of this paper are: hep-th
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The categories of this paper are: gr-qc
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The categories of this paper are: solv-int
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The categories of this paper are: funct-an
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The categories of this paper are: stat
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The categories of this paper are: cs
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The categories of this paper are: nucl-th
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The categories of this paper are: physics
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The categories of this paper are: adap-org
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The categories of this paper are: atom-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: acc-phys
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The categories of this paper are: alg-geom
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: patt-sol