Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spiral shocks in the accretion disk of the dwarf nova U Geminorum   We present a study of the observable spectral manifestations associated with
spiral shocks within quiescent accretion disks and compare them with
observations of the dwarf nova U Geminorum. Our results indicate that the
orbital behaviour of the hydrogen emission line profile in the spectrum of U
Gem can be reproduced via a simple model of the accretion disk with two
symmetrically located spiral shocks with the spiral angle theta about 60
degrees. This provides for the first time convincing evidence for the existence
of spiral shocks in the accretion disk of a cataclysmic variable in quiescence.

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The categories of this paper are: quant-ph
2
The categories of this paper are: math
22
The categories of this paper are: chao-dyn
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
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The categories of this paper are: adap-org
5
The categories of this paper are: gr-qc
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
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The categories of this paper are: funct-an
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-ph
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The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
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The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol