Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Long-Slit Spectroscopy of Parsec-Scale Jets from DG Tauri   We present observational results from optical long-slit spectroscopy of
parsec-scale jets of DG Tau. From HH 158 and HH 702, the optical emission lines
of H_alpha, [O I] 6300, 6363, [N II] 6548, 6584, and [S II] 6716, 6731 are
obtained. The kinematics and physical properties (i.e., electron density,
electron temperature, ionization fraction, and mass-loss rate) are investigated
along the blueshifted jet up to 650 arcseconds distance from the source. For HH
158, the radial velocity ranges from -50 to -250 km/s. The proper motion of the
knots is 0.196 - 0.272 /yr. The electron density is ~ 10^{4}/cm^{3} close to
the star, and decreases to ~ 10^{2} /cm^{3} at 14 arcseconds away from the
star. Ionization fraction indicates that the gas is almost neutral in the
vicinity of the source. It increases up to over 0.4 along the distance. HH 702
is located at ~ 650 arcseconds from the source. It shows ~ -80 km/s in the
radial velocity. Its line ratios are similar to those at knot C of HH 158. The
mass-loss rate is estimated to be about ~ 10^{-7} M_{sun}/yr, which is similar
to values obtained from previous studies.

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The categories of this paper are: q-fin
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The categories of this paper are: hep-lat
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The categories of this paper are: hep-th
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The categories of this paper are: comp-gas
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The categories of this paper are: hep-ex
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The categories of this paper are: physics
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The categories of this paper are: q-bio
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The categories of this paper are: alg-geom
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The categories of this paper are: gr-qc
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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: supr-con
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The categories of this paper are: adap-org
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The categories of this paper are: nucl-ex
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The categories of this paper are: quant-ph
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The categories of this paper are: bayes-an