Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Atacama Cosmology Telescope: A search for Planet 9   We use Atacama Cosmology Telescope (ACT) observations at 98 GHz (2015--2019),
150 GHz (2013--2019) and 229 GHz (2017--2019) to perform a blind
shift-and-stack search for Planet 9. The search explores distances from 300 AU
to 2000 AU and velocities up to 6.3 arcmin per year, depending on the distance.
For a 5 Earth-mass Planet 9 the detection limit varies from 325 AU to 625 AU,
depending on the sky location. For a 10 Earth-mass planet the corresponding
range is 425 AU to 775 AU. The search covers the whole 18,000 square degrees of
the ACT survey, though a slightly deeper search is performed for the parts of
the sky consistent with Planet 9's expected orbital inclination. No significant
detections are found, which is used to place limits on the mm-wave flux density
of Planet 9 over much of its orbit. Overall we eliminate roughly 17% and 9% of
the parameter space for a 5 and 10 Earth-mass Planet 9 respectively. We also
provide a list of the 10 strongest candidates from the search for possible
follow-up. More generally, we exclude (at 95% confidence) the presence of an
unknown Solar system object within our survey area brighter than 4--12 mJy
(depending on position) at 150 GHz with current distance $300 \text{ AU} < r <
600 \text{ AU}$ and heliocentric angular velocity $1.5'/\text{yr} < v \cdot
\frac{500 \text{ AU}}{r} < 2.3'\text{yr}$, corresponding to low-to-moderate
eccentricities. These limits worsen gradually beyond 600 AU, reaching 5--15 mJy
by 1500 AU.

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The categories of this paper are: math
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
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The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
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The categories of this paper are: hep-lat
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The categories of this paper are: physics
36
The categories of this paper are: cmp-lg
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The categories of this paper are: gr-qc
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The categories of this paper are: dg-ga
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The categories of this paper are: bayes-an
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The categories of this paper are: cond-mat
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The categories of this paper are: cs
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The categories of this paper are: acc-phys
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The categories of this paper are: chem-ph