Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Nuclear Gas Dynamics and Star Formation of NGC 7469   We report interferometric radio CO2-1 observations at a resolution of 0.7",
and 0.085" resolution adaptive optics K-band spectroscopy of the inner few
arcseconds of NGC7469. The CO2-1 map shows a ring of molecular clouds and a
bright extended nucleus, with a bar or pair of spiral arms between them. The
dynamical structure of both the radio CO2-1 and the K-band H2 1-0S(1) lines can
be reproduced using an axisymmetric mass model comprising 3 components: a broad
disk, a ring 4-5" across, and an inner nuclear ring about 0.5" across. No
non-circular motions faster than the velocity residuals of 25 km/s are seen,
although this may be because in some cases a secondary bar is not expected to
cause gas inflow. From the dynamical mass and estimates of the stellar mass we
find that the CO-to-H_2 conversion is 0.4-0.8 times that for the Milky Way. The
H2 1-0S(1) morphology peaks at the nucleus, although there is no strong nuclear
mass concentration. The 1-0S(1) is likely to originate in X-ray of gas by the
AGN rather than via star formation. Using the 2.3um stellar CO2-0 absorption
and the continuum slope we have directly resolved the nuclear star cluster to
be 0.15-0.20" across, and find that it is asymmetric. This cluster has an age
of less than about 60Myr and contributes 20-30% of the nuclear K-band light,
and about 10% of the nuclear bolometric luminosity. Within a radius of ~4" gas
contributes more than half the total mass; but in the nucleus, within a radius
of 0.1", it is likely that most of the mass is due to stars

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The categories of this paper are: alg-geom
19
The categories of this paper are: eess
18
The categories of this paper are: econ
5
The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
3
The categories of this paper are: physics
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The categories of this paper are: funct-an
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The categories of this paper are: nlin
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The categories of this paper are: q-fin
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The categories of this paper are: acc-phys
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The categories of this paper are: hep-lat
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The categories of this paper are: q-alg
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The categories of this paper are: mtrl-th
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The categories of this paper are: hep-th
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The categories of this paper are: nucl-th