Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High Resolution X-ray Spectroscopy of T Tauri Stars in the Taurus-Auriga
  Complex   Differences have been reported between the X-ray emission of accreting and
non-accreting stars. Some observations have suggested that accretion shocks
could be responsible for part of the X-ray emission in Classical T Tauri stars
(CTTS). We present high-resolution X-ray spectroscopy of nine pre-main sequence
stars in order to test the proposed spectroscopic differences between accreting
and non-accreting pre-main sequence stars. We use X-ray spectroscopy from the
XMM-Newton Reflection Grating Spectrometers and the EPIC instruments. We
interpret the spectra using optically thin thermal models with variable
abundances, together with an absorption column density. For BP Tau and AB Aur
we derive electron densities from the O VII triplets. Using the O VII/O VIII
count ratios as a diagnostic for cool plasma, we find that CTTS display a soft
excess (with equivalent electron temperatures of ~ 2.5-3 MK) when compared with
WTTS or zero-age main-sequence stars. Although the O VII triplet in BP Tau is
consistent with a high electron density (3.4 x 10^11 cm^-3), we find a low
density for the accreting Herbig star AB Aur (n_e < 10^10 cm^-3). The element
abundances of accreting and non-accreting stars are similar. The Ne abundance
is found to be high (4-6 times the Fe abundance) in all K and M-type stars. In
contrast, for the three G-type stars (SU Aur, HD 283572, and HP Tau/G2), we
find an enhanced Fe abundance (0.4-0.8 times solar photospheric values)
compared to later-type stars. Adding the results from our sample to former
high-resolution studies of T Tauri stars, we find a soft excess in all
accreting stars, but in none of the non-accretors. On the other hand, high
electron density and high Ne/Fe abundance ratios do not seem to be present in
all accreting pre-main sequence stars.

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The categories of this paper are: atom-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-th
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The categories of this paper are: math-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: hep-ex
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The categories of this paper are: q-alg
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The categories of this paper are: q-bio
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The categories of this paper are: chem-ph
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The categories of this paper are: eess
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The categories of this paper are: funct-an
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The categories of this paper are: stat
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The categories of this paper are: hep-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: mtrl-th