Comparison of synthetic maps from truncated jet-formation models with YSO jet observations

II. The effect of varying inclinations^⋆

¹ Institute of Astronomy and Astrophysics, Section Computational Physics, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
e-mail: matthias.stute@tat.physik.uni-tuebingen.de
² High Performance Computing Center Stuttgart (HLRS), Universität Stuttgart, 70550 Stuttgart, Germany

Received: 25 August 2011
Accepted: 22 November 2011

Abstract

Context. Analytical radially self-similar models are the best available solutions describing disk-winds, but they need several improvements. In a previous article, we introduced models of jets from truncated disks, i.e. evolved in time numerical simulations based on a radially self-similar MHD solution but including the effects of a finite radius of the jet-emitting disk, hence the outflow. In Paper I of this series, we compared these models with available observational data by varying the jet density and velocity, the mass of the protostar, and the radius of this truncation.

Aims. In Paper I, we assumed that the jet lies in the plane of the sky. In this paper, we investigate the effect of different inclinations of the jet.

Methods. To compare our models with observed jet widths inferred from recent optical images taken with HST and AO, we again created emission maps in different forbidden lines, and from such emission maps determined the jet width as the full-width half-maximum of the emission.

Results. We can reproduce the jet width of DG Tau and its variations very well, and the derived inclination of 40° is in excellent agreement with literature values of 32–52°. In CW Tau we overestimate the inclination in our best-fit model. In the other objects, we cannot find appropriate models that reproduce the variations in the observed jet widths. Only the average jet width itself is well modeled.

Conclusions. We conclude that truncation – i.e. taking the finite radius of the jet launching region into account – is needed to reproduce the observed jet widths, and our simulations limit the possible range of truncation radii. The effects of inclination are important for modeling the intrinsic variations seen in observed jet widths. Our models can be used to infer the inclinations in the observed sample independently; however, a parameter study with a finer grid of parameters is needed.