Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Time-dependent ejection velocity model for the outflow of Hen 3--1475   We present 2D axisymmetric and 3D numerical simulations of the
proto-planetary nebula Hen 3-1475, which is characterized by a remarkably
highly collimated optical jet, formed by a string of shock-excited knots along
the axis of the nebula. It has recently been suggested that the kinematical and
morphological properties of the Hen 3-1475 jet could be the result of an
ejection variability of the central source (Riera et al. 2003). The
observations suggest a periodic variability of the ejection velocity
superimposed on a smoothly increasing ejection velocity ramp. From our
numerical simulations, we have obtained intensity maps (for different optical
emission lines) and position-velocity diagrams, in order to make a direct
comparison with the HST observations of this object. Our numerical study allows
us to conclude that a model of a precessing jet with a time-dependent ejection
velocity, which is propagating into an ISM previously perturbed by an AGB wind,
can succesfully explain both the morphological and the kinematical
characteristics of this proto-planetary nebula.

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The categories of this paper are: chao-dyn
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The categories of this paper are: dg-ga
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The categories of this paper are: atom-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: q-alg
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The categories of this paper are: q-fin
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The categories of this paper are: supr-con
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The categories of this paper are: cond-mat
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The categories of this paper are: nlin
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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: solv-int
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The categories of this paper are: math-ph
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The categories of this paper are: math
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The categories of this paper are: comp-gas
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The categories of this paper are: acc-phys