Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Infrared H3+ and CO Studies of the Galactic Core: GCIRS 3 and GCIRS 1W   We have obtained improved spectra of key fundamental band lines of H3+,
R(1,1)l, R(3,3)l, and R(2,2)l, and ro-vibrational transitions of CO on
sightlines toward the luminous infrared sources GCIRS 3 and GCIRS 1W, each
located in the Central Cluster of the Galactic center within several arcseconds
of Sgr A*. The spectra reveal absorption occurring in three kinds of gaseous
environments: (1) cold dense and diffuse gas associated with foreground
spiral/lateral arms; (2) warm and diffuse gas absorbing over a wide and mostly
negative velocity range, which appears to fill a significant fraction of the
Galaxy's Central Molecular Zone (CMZ); and (3) warm, dense and compact clouds
with velocities near +50 km s^-1 probably within 1-2 pc of the center. The
absorptions by the first two cloud types are nearly identical for all the
sources in the Central Cluster, and are similar to those previously observed on
sightlines from Sgr A* to 30 pc east of it. Cloud type (3), which has only been
observed toward the Central Cluster, shows distinct differences between the
sightlines to GCIRS 3 and GCIRS 1W, which are separated on the sky by only 0.33
pc in projection. We identify this material as part of an inward extension of
the Circumnuclear Disk previously known from HCN mapping. Lower limits on the
products of the hydrogen ionization rate zeta and the path length L are 2.3 x
10^5 cm s^-1 and 1.5 x 10^3 cm s^-1 for the warm and diffuse CMZ gas and for
the warm and dense clouds in the core, respectively. The limits indicate that
the ionization rates in these regions are well above 10^-15 s^-1.

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The categories of this paper are: comp-gas
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The categories of this paper are: q-fin
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The categories of this paper are: physics
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The categories of this paper are: cond-mat
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The categories of this paper are: econ
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The categories of this paper are: cmp-lg
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The categories of this paper are: q-alg
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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: nucl-th
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The categories of this paper are: funct-an
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The categories of this paper are: hep-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: chao-dyn
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The categories of this paper are: q-bio
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The categories of this paper are: hep-ex