Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A New Probe of the Planet-Forming Region in T Tauri Disks   We present new observations of the FUV (1100-2200 Angstrom) radiation field
and the near- to mid-IR (3--13.5 micron) spectral energy distribution (SED) of
a sample of T Tauri stars selected on the basis of bright molecular disks (GM
Aur, DM Tau, LkCa15). In each source we find evidence for Ly alpha induced H2
fluorescence and an additional source of FUV continuum emission below 1700
Angstroms. Comparison of the FUV spectra to a model of H2 excitation suggests
that the strong continuum emission is due to electron impact excitation of H2.
The ultimate source of this excitation is likely X-ray irradiation which
creates hot photo-electrons mixed in the molecular layer. Analysis of the SED
of each object finds the presence of inner disk gaps with sizes of a few AU in
each of these young (~1 Myr) stellar systems. We propose that the presence of
strong H2 continuum emission and inner disk clearing are related by the
increased penetration power of high energy photons in gas rich regions with low
grain opacity.

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The categories of this paper are: q-alg
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
12
The categories of this paper are: nucl-th
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The categories of this paper are: nucl-ex
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
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The categories of this paper are: eess
11
The categories of this paper are: hep-lat