Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Optical Morphology, Inclination and Expansion Velocity of the Ejected
  Shell of Nova Monocerotis 2012   The morphology of the ejected shell of the He/N Nova Monocerotis 2012
outburst was studied in detail. Synthetic line profile spectra were compared to
the [O {\sc iii}] 4959,5007 \AA\ emission line profiles in order to find the
best fit morphology, inclination angle and maximum expansion velocity of the
ejected shell. The simplest morphology was found to be that of a bipolar
structure with an inclination angle of 82$\pm6$ degrees and a maximum expansion
velocity of 2400$^{+300}_{-200}$ km/s (at day 130 after outburst). Such a high
degree of shaping is un-expected for a system with a main sequence star (as
suspected from the systems colors). The degree of shaping may be disentangled
with resolved optical imaging. Furthermore, these results may be confirmed with
radio imaging which is expected to follow the same gross features of the
outburst as the optical band and the high inclination implied here can be
corroborated with a 7.1 hour period which has been suggested to arise from
partial eclipses of extended emission by an accretion disk rim.

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The categories of this paper are: quant-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: funct-an
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The categories of this paper are: math-ph
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The categories of this paper are: q-bio
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The categories of this paper are: gr-qc
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The categories of this paper are: acc-phys
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The categories of this paper are: stat
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The categories of this paper are: solv-int
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-ex
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The categories of this paper are: supr-con
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The categories of this paper are: cmp-lg
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The categories of this paper are: ao-sci
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The categories of this paper are: q-alg