Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On The Hydrogen Emission From The Type Ia Supernova 2002ic   The discovery of SN 2002ic and subsequent spectroscopic studies have led to
the surprising finding that SN 2002ic is a Type Ia supernova with strong
ejecta-circumstellar interaction. Here we show that nearly 1 year after the
explosion the supernova has become fainter overall, but the H$\alpha$ emission
has brightened and broadened dramatically compared to earlier observations. We
have obtained spectropolarimetry data which show that the hydrogen-rich matter
is highly aspherically distributed. These observations suggest that the
supernova exploded inside a dense, clumpy, disk-like circumstellar environment.

25
The categories of this paper are: patt-sol
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The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
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The categories of this paper are: nucl-ex
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The categories of this paper are: q-bio
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The categories of this paper are: eess
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The categories of this paper are: solv-int
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-th
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
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The categories of this paper are: plasm-ph