Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Abundant Methanol Ice toward a Massive Young Stellar Object in the
  Central Molecular Zone   Previous radio observations revealed widespread gas-phase methanol (CH$_3$OH)
in the Central Molecular Zone (CMZ) at the Galactic center (GC), but its origin
remains unclear. Here, we report the discovery of CH$_3$OH ice toward a star in
the CMZ, based on a Subaru $3.4$-$4.0\ \mu$m spectrum, aided by NASA/IRTF $L'$
imaging and $2$-$4\ \mu$m spectra. The star lies $\sim8000$ au away in
projection from a massive young stellar object (MYSO). Its observed high
CH$_3$OH ice abundance ($17\%\pm3\%$ relative to H$_2$O ice) suggests that the
$3.535\ \mu$m CH$_3$OH ice absorption likely arises in the MYSO's extended
envelope. However, it is also possible that CH$_3$OH ice forms with a higher
abundance in dense clouds within the CMZ, compared to within the disk. Either
way, our result implies that gas-phase CH$_3$OH in the CMZ can be largely
produced by desorption from icy grains. The high solid CH$_3$OH abundance
confirms the prominent $15.4\ \mu$m shoulder absorption observed toward GC
MYSOs arises from CO$_2$ ice mixed with CH$_3$OH.

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The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
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The categories of this paper are: funct-an
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The categories of this paper are: alg-geom
2
The categories of this paper are: math
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The categories of this paper are: cmp-lg
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The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org