Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Application of the spectral subtraction technique to the CaII H & K and
  H$\epsilon$ lines in a sample of chromospherically active binaries   We present new spectroscopic observations in the Ca~{\sc ii} H \& K line
region for a sample of 28 chromospherically active binary systems (RS$~$CVn and
BY$~$Dra classes), with different activity levels. By using the spectral
subtraction technique (subtraction of a synthesized stellar spectrum
constructed from reference stars of similar spectral type and luminosity class)
we obtain the active-chromosphere contribution to the Ca~{\sc ii} H \& K lines
and to the H$\epsilon$ line when it is present. We have compared the emission
equivalent widths obtained with this technique with those obtained by
reconstruction of the absorption line profile below the emission peak(s). The
emissions arising from each individual star were obtained when it was possible
to deblend the contribution of both components. The Ca~{\sc ii} line profiles
corresponding to different seasons and orbital phases are analysed in order to
determine the contribution of each component and to study the chromospheric
activity variations.

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The categories of this paper are: cs
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The categories of this paper are: patt-sol
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The categories of this paper are: eess
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The categories of this paper are: physics
11
The categories of this paper are: hep-lat
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The categories of this paper are: nucl-ex
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The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
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The categories of this paper are: gr-qc
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The categories of this paper are: quant-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: hep-th
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The categories of this paper are: chem-ph
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The categories of this paper are: math
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The categories of this paper are: solv-int
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The categories of this paper are: q-fin