Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Population of very young Brown Dwarfs and free-floating Planets in
  Orion   We describe the results of a very deep imaging survey of the Trapezium
Cluster in the IJH bands, using the UKIRT high resolution camera UFTI.
Approximately 32% of the 515 point sources detected are brown dwarf candidates,
including several free floating objects with masses below the Deuterium burning
(planetary) threshold at 0.013 solar masses, which are detectable because of
their extreme youth. We have confidence that almost all the sources detected
are cluster members, since foreground contamination is minimal in the 33
arcmin^2 area surveyed and the dense backdrop of OMC-1 obscures all background
stars at these wavelengths. Extinction is calculated from the (J-H)colours,
permitting accurate luminosity estimates and temperatures are derived from the
dereddened (I-J) colours. There is some evidence for a cut-off in the
luminosity function below the level corresponding to several Jupiter masses,
which may represent the bottom end of the IMF. Since star formation is complete
in the Trapezium this limit could have wide significance, if confirmed.
However, it could well be an effect of the dispersal of the molecular cloud by
the central O-type stars, a process whose timescale will vary between star
formation regions.

12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
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The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
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The categories of this paper are: dg-ga
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The categories of this paper are: funct-an
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The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg