Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: X-ray accretion signatures in the close CTTS binary V4046 Sgr   We present Chandra HETGS observations of the classical T Tauri star (CTTS)
V4046 Sgr. The He-like triplets of O VII, Ne IX, and Si XIII are clearly
detected. Similar to the CTTS TW Hya and BP Tau, the forbidden lines of O VII
and Ne IX are weak compared to the intercombination line, indicating high
plasma densities in the X-ray emitting regions. The Si XIII triplet, however,
is within the low-density limit, in agreement with the predictions of the
accretion funnel infall model with an additional stellar corona. V4046 Sgr is
the first close binary exhibiting these features. Together with previous
high-resolution X-ray data on TW Hya and BP Tau, and in contrast to T Tau, now
three out of four CTTS show evidence of accretion funnels.

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The categories of this paper are: adap-org
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The categories of this paper are: econ
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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: supr-con
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The categories of this paper are: gr-qc
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The categories of this paper are: q-alg
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-ex
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The categories of this paper are: dg-ga
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The categories of this paper are: chem-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: q-bio
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The categories of this paper are: ao-sci
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The categories of this paper are: funct-an
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The categories of this paper are: mtrl-th