Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Bloated Stars as AGN Broad Line Clouds: The Emission Line Spectrum   The Bloated Stars Scenario proposes that AGN broad line emission originates
in the winds or envelopes of bloated stars (BS). Its main advantage over BLR
cloud models is the gravitational confinement of the gas and its major
difficulty the large estimated number of BSs and resulting high mass loss rate.
We calculate the emission line spectrum by a detailed numerical photoionization
code for a wide range of wind structures and a detailed QSO nucleus model with
L(ion)=7E45 erg/s, M(bh)=8E7 Mo. The size and boundary density of the wind are
determined by various processes: Comptonization by the central ionizing source
(calculated self consistently), tidal disruption by the black hole and the
limit set by the wind's finite mass. We find that the emission spectrum is
mainly determined by the conditions at the boundary of the line emitting
fraction of the wind rather than by its internal structure. Comptonization
results in very high ionization parameters at the boundary which produces an
excess of unobserved broad high excitation forbidden lines. The finite mass
constraint limits the wind size, increases the boundary density and thus
improves the results. Slow decelerating mass-constrained flows with high gas
densities (1E8-1E12 cm^-3) are as success- ful as clouds in reproducing the
observed lines. Only 5E4 dense wind BSs are required in the inner 1/3 pc. This
small fraction approaches that of super- giants (SG) in the solar neighborhood
and the mass loss is consistent with the observational constraints. The BS
number is a very sensitive function of the wind structure. SG-like BSs are
ruled out by their high mass loss. BSs with dense winds can reproduce the BLR
line spectrum and be supported by the stellar population without excessive mass
loss and collisional destruction rates.

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The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
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The categories of this paper are: acc-phys
18
The categories of this paper are: econ
3
The categories of this paper are: physics
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The categories of this paper are: quant-ph
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The categories of this paper are: nlin
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The categories of this paper are: math
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
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The categories of this paper are: cs
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The categories of this paper are: gr-qc
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The categories of this paper are: alg-geom
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The categories of this paper are: cond-mat
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The categories of this paper are: solv-int
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The categories of this paper are: hep-ex