Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: BANYAN. IX. The Initial Mass Function and Planetary-Mass Object Space
  Density of the TW Hya Association   A determination of the initial mass function (IMF) of the current, incomplete
census of the 10 Myr-old TW Hya association (TWA) is presented. This census is
built from a literature compilation supplemented with new spectra and 17 new
radial velocities, as well as a re-analysis of Hipparcos data that confirmed HR
4334 (A2Vn) as a member. Though the dominant uncertainty in the IMF remains
census incompleteness, a detailed statistical treatment is carried out to make
the IMF determination independent of binning, while accounting for small number
statistics. The currently known high-likelihood members are fitted by a
log-normal distribution with a central mass of $0.21^{+0.11}_{-0.06}$
$M_{\odot}$ and a characteristic width of $0.8^{+0.2}_{-0.1}$ dex in the 12
$M_{\rm Jup}$-2 $M_{\odot}$ range, whereas a Salpeter power law with $\alpha =
2.2^{+1.1}_{-0.5}$ best describes the IMF slope in the $0.1-2$ $M_{\odot}$
range. This characteristic width is higher than other young associations, which
may be due to incompleteness in the current census of low-mass TWA stars. A
tentative overpopulation of isolated planetary-mass members similar to 2MASS
J11472421-2040204 and 2MASS J11193254-1137466 is identified: this indicates
that there might be as many as $10^{+13}_{-5}$ similar members of TWA with
hot-start model-dependent masses estimated at $\sim$ 5-7 $M_{\rm Jup}$, most of
which would be too faint to be detected in 2MASS. Our new radial velocity
measurements corroborate the membership of 2MASS J11472421-2040204, and secure
TWA 28 (M8.5$\gamma$), TWA 29 (M9.5$\gamma$) and TWA 33 (M4.5e) as members. The
discovery of 2MASS J09553336-0208403, a young L7-type interloper unrelated to
TWA, is also presented.

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The categories of this paper are: cmp-lg
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The categories of this paper are: nucl-ex
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The categories of this paper are: quant-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: plasm-ph
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The categories of this paper are: hep-th
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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: alg-geom
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The categories of this paper are: cond-mat
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The categories of this paper are: comp-gas
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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: stat
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The categories of this paper are: funct-an
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The categories of this paper are: adap-org