883 research outputs found
Comparison of synthetic maps from truncated jet-formation models with YSO jet observations
(abridged) Significant progress has been made in the last years in the
understanding of the jet formation mechanism through a combination of numerical
simulations and analytical MHD models for outflows characterized by the
symmetry of self-similarity. In a previous article we introduced models of
truncated jets from 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 and thus the outflow. These models need now to
be compared with available observational data. A direct comparison of the
results of combined analytical theoretical models and numerical simulations
with observations has not been performed as yet. In order to compare our models
with observed jet widths inferred from recent optical images taken with HST and
AO observations, we use a new set of tools to create emission maps in different
forbidden lines, from which we determine the jet width as the FWHM of the
emission. It is shown that the untruncated analytical disk outflow solution
considered here cannot fit the small jet widths inferred by observations of
several jets. Various truncated disk-wind models are examined, whose extracted
jet widths range from higher to lower values compared to the observations. Thus
we can fit the observed range of jet widths by tuning our models. We conclude
that truncation is necessary to reproduce the observed jet widths and our
simulations limit the possible range of truncation radii. We infer that the
truncation radius, which is the radius on the disk mid-plane where the
jet-emitting disk switches to a standard disk, must be between around 0.1 up to
about 1 AU in the observed sample for the considered disk-wind solution. One
disk-wind simulation with an inner truncation radius at about 0.11 AU also
shows potential for reproducing the observations, but a parameter study is
needed.Comment: accepted for publication in A & A, 14 pages, 21 figure
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