Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Time-Dependent MHD Shocks and Line Emission: The Case of the DG Tau Jet   The line emission from a growing number of Herbig-Haro jets can be observed
and resolved at angular distances smaller than a few arcseconds from the
central source. The interpretation of this emission is problematic, since the
simplest model of a cooling jet cannot sustain it. It has been suggested that
what one actually observes are shocked regions with a filling factor of $\sim
1%$. In this framework, up to now, comparisons with observations have been
based on stationary shock models. Here we introduce for the first time the
self-consistent dynamics of such shocks and we show that considering their
properties at different times, i.e. locations, we can reproduce observational
data of the DG Tau microjet. In particular, we can interpret the spatial
behavior of the [SII]6716/6731 and [NII]/[OI]6583/6300 line intensity ratios
adopting a set of physical parameters that yield values of mass loss rates and
magnetic fields consistent with previous estimates. We also obtain the values
of the mean ionization fraction and electron density along the jet, compare
these values with the ones derived from observations using the sulfur doublet
to constrain the electron density (e.g. Bacciotti et al. 1995).

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The categories of this paper are: atom-ph
0
The categories of this paper are: hep-ph
17
The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
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The categories of this paper are: chem-ph
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The categories of this paper are: supr-con
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The categories of this paper are: mtrl-th
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The categories of this paper are: physics
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The categories of this paper are: q-alg
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The categories of this paper are: comp-gas