Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spatially resolved H2 emission from the disk around T Tau N   We report the detection of quiescent H2 emission in a spatially resolved
ring-like structure within 100 AU of T Tau N. We present evidence to show that
the emission most likely arises from shocks in the atmosphere of a nearly
face-on disk around T Tau N. Using high spatial resolution 3D spectroscopic
K-band data, we trace the spatial distribution of several H2 NIR rovibrational
lines in the vicinity of T Tau N. We detect weak H2 emission from the v=1-0
S(0), S(1), Q(1) lines and the v=2-1 S(1) line in a ring-like structure around
T Tau N between 0.1'' (~15 AU) and 0.7'' (~100AU) from the star. The v=1-0 S(0)
and v=2-1 S(1) lines are detected only in the outer parts of the ring
structure. Closer to the star, the strong continuum limits our sensitivity to
these lines. The total flux of the v=1-0 S(1) line is 1.8 *10^{-14} ergs
s^{-1}cm^{-2}, similar to previous measurements of H2 in circumstellar disks.
The velocity of the H2 emitting gas around T Tau N is consistent with the rest
velocity of the star, and the H2 does not seem to be part of a collimated
outflow. Both shocks impinging on the surface of a disk and irradiation of a
disk by UV-photons and X-rays from the central star are plausible candidates
for the H2 excitation mechanism. However, irradiation should not create a large
degree of excitation at radii larger than 20 AU. Most likely the H2 emission
arises in the atmosphere of a flared disk with radius 85-100 AU and mass
0.005-0.5Msun, where the gas is excited by shocks created when a wide-angle
wind impinges on the disk. The H2 emission could also originate from shock
excitation in the cavity walls of an envelope, but this requires an unusually
high velocity of the wide-angle wind from T Tau N.

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The categories of this paper are: supr-con
9
The categories of this paper are: nlin
3
The categories of this paper are: physics
4
The categories of this paper are: cond-mat
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The categories of this paper are: q-fin
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The categories of this paper are: dg-ga
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The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
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The categories of this paper are: funct-an
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The categories of this paper are: hep-ex
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The categories of this paper are: hep-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: stat
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The categories of this paper are: cs
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The categories of this paper are: alg-geom
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The categories of this paper are: solv-int