Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Transient Heavy Element Absorption Systems in Novae: Episodic Mass
  Ejection from the Secondary Star   A high-resolution spectroscopic survey of postoutburst novae reveals
short-lived heavy element absorption systems in a majority of novae near
maximum light, having expansion velocities of 400-1000 km/s and velocity
dispersions between 35-350 km/s. A majority of systems are accelerated
outwardly, and they all progressively weaken and disappear over timescales of
weeks. A few of the systems having narrow, deeper absorption reveal a rich
spectrum of singly ionized Sc, Ti, V, Cr, Fe, Sr, Y, Zr, and Ba lines. Analysis
of the richest such system, in Nova LMC 2005, shows the excitation temperature
to be 104 K and elements lighter than Fe to have abundance enhancements over
solar values by up to an order of magnitude. The gas causing the absorption
systems must be circumbinary and its origin is most likely mass ejection from
the secondary star. The absorbing gas pre-exists the outburst and may represent
episodic mass transfer events from the secondary star that initiate the nova
outburst(s). If SNe Ia originate in single degenerate binaries, such absorption
systems could be detectable before maximum light

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The categories of this paper are: econ
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The categories of this paper are: patt-sol
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The categories of this paper are: q-fin
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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: math
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The categories of this paper are: funct-an
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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: cond-mat
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The categories of this paper are: comp-gas
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The categories of this paper are: alg-geom
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The categories of this paper are: cs
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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: chao-dyn