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Issue A&A Volume 367, Number 3, March I 2001 Page(s) 959 - 966 Section Diffuse matter in space DOI 10.1051/0004-6361:20000415

A&A 367, 959-966 (2001)
DOI: 10.1051/0004-6361:20000415

A precessing, variable velocity jet model for DG Tauri

A. Raga^{1, 2}, S. Cabrit², C. Dougados^{3, 4} and C. Lavalley<sup>3

1</sup>  Instituto de Astronomía, UNAM, Apartado Postal 70-264, 04510 D. F., Mexico
²  Observatoire de Paris, DEMIRM, UMR 8540 du CNRS, 61 avenue de l'Observatoire, 75014 Paris, France
³  Laboratoire d'Astrophysique, Observatoire de Grenoble, CNRS/UJF UMR 5571, BP 53, 38041 Grenoble Cedex 9, France
⁴  Canada-France-Hawaii Telescope Corporation, PO Box 1597, Kamuela HI 96743, USA

(Received 1 September 2000 / Accepted 30 November 2000)

Abstract
We present a first attempt at reproducing the morphology and kinematical properties of the DG Tau microjet using a 3D hydrodynamical numerical simulation of a precessing, variable velocity jet. Synthetic maps and position-velocity diagrams in H and [O I]6300 are calculated and compared with recent imaging and spectro-imaging observations (Lavalley-Fouquet et al. 2000; Dougados et al. 2000). Several observed properties are qualitatively reproduced, such as the knot separation, width, and asymmetric morphology, and the increase in ionization fraction and decrease in electronic density away from the star. However, the predicted kinematics in the region between the two jet knots differs from the observed behaviour. This discrepancy probably results from our simple assumption of a sinusoidal velocity variability, and points to a more complex velocity time-variability in the jet from DG Tau.

Key words: hydrodynamics -- stars: individual: DG Tau -- ISM: HH objects -- ISM: individual objects: HH 158 -- ISM: jets and outflows

Offprint request: A. Raga, raga@astroscu.unam.mx

SIMBAD Objects in preparation

© ESO 2001

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