Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Supernova PTF 09uj: A possible shock breakout from a dense circumstellar
  wind   Type-IIn supernovae (SNe), which are characterized by strong interaction of
their ejecta with the surrounding circumstellar matter (CSM), provide a unique
opportunity to study the mass-loss history of massive stars shortly before
their explosive death. We present the discovery and follow-up observations of a
Type IIn SN, PTF 09uj, detected by the Palomar Transient Factory (PTF).
Serendipitous observations by GALEX at ultraviolet (UV) wavelengths detected
the rise of the SN light curve prior to the PTF discovery. The UV light curve
of the SN rose fast, with a time scale of a few days, to a UV absolute AB
magnitude of about -19.5. Modeling our observations, we suggest that the fast
rise of the UV light curve is due to the breakout of the SN shock through the
dense CSM (n~10^10 cm^-3). Furthermore, we find that prior to the explosion the
progenitor went through a phase of high mass-loss rate (~0.1 solar mass per
year) that lasted for a few years. The decay rate of this SN was fast relative
to that of other SNe IIn.

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The categories of this paper are: math-ph
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The categories of this paper are: q-alg
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The categories of this paper are: math
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The categories of this paper are: econ
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The categories of this paper are: eess
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The categories of this paper are: plasm-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: mtrl-th
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The categories of this paper are: chem-ph
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The categories of this paper are: stat
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The categories of this paper are: q-bio
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The categories of this paper are: nucl-ex
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The categories of this paper are: ao-sci
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The categories of this paper are: atom-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: patt-sol