Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A search for brown-dwarf like secondaries in cataclysmic variables   We present VTL/ISAAC infrared spectroscopy of a sample of short orbital
period cataclysmic variables which are candidates for harboring substellar
companions. We have detected the KI and NaI absorption lines of the companion
star in VY Aqr. The overall spectral distribution in this system is best fit
with a M9.5 type dwarf spectra, implying a distance of $100 \pm 10$ pc. VY Aqr
seems to fall far from the theoretical distribution of secondary star
temperatures around the orbital period minimum. Fitting of the IR spectral
energy distribution (SED) was performed by comparing the observed spectrum with
late-type templates. The application of such a spectral fitting procedure
suggests that the continuum shape in the 1.1-2.5 $\mu$m spectral region in
short orbital period cataclysmic variables may be an useful indicator of the
companion spectral type. The SED fitting for RZ Leo and CU Vel suggests M5 type
dwarf companions, and distances of 340 $\pm$ 110 and 150 $\pm$ 50 pc,
respectively. These systems may be placed in the upper evolution branch for
short period cataclysmic variables.

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The categories of this paper are: math
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The categories of this paper are: physics
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The categories of this paper are: solv-int
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The categories of this paper are: stat
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The categories of this paper are: nucl-ex
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The categories of this paper are: acc-phys
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The categories of this paper are: nlin
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The categories of this paper are: cmp-lg
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The categories of this paper are: mtrl-th
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The categories of this paper are: quant-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: alg-geom
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The categories of this paper are: dg-ga
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The categories of this paper are: nucl-th
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The categories of this paper are: cond-mat
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The categories of this paper are: hep-lat