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Astron. Astrophys. 348, 584-593 (1999)
The bow shock and jet in L483
J.V. Buckle,
J. Hatchell and
G.A. Fuller
Department of Physics, UMIST, P.O. Box 88, Manchester M60 1QD, UK
Received 27 January 1999 / Accepted 25 May 1999
Abstract
The physical parameters of jets are still poorly understood. Here
we present long slit spectra of the molecular hydrogen emission from
the jet powered by the young stellar object in L483, from which we
obtain details of the jet structure and shock velocities. The jet has
a knotty structure, and, in addition, weaker emission is seen between
the knots, so that emission is observed along the full length of the
jet. The ![[FORMULA]](img1.gif)
emission from the bright bow
shock at the end of the jet has an excitation temperature of
2200 K, and is consistent with a bow C-shock of speed
40-45 km s-1. Lower speed J-shocks, which could also
match the emission, are ruled out by
a lower limit on the shock speed provided by an analysis of the CO
emission from the outflow. Assuming a jet velocity of
![[FORMULA]](img2.gif)
km s-1, this shock
velocity indicates that the jet from L483 has a density of about 10
times less that the medium into which it is propagating. The
knots are possibly due to jet
instabilities, or could be indicative of episodic activity. Emission
from between the knots could be indicative of a partially molecular
jet, entrainment in a mixing layer, or unresolved sub-knots. These
possibilities, and how they impact on outflow models, are
discussed.
Key words: stars:
formation 
ISM: individual objects:
L483
ISM: jets and
outflows
ISM: kinematics and
dynamics
ISM: molecules
Send offprint requests to: J.V. Buckle (jvb@bootes.phy.umist.ac.uk)
Contents
- 1. Introduction
- 2. Observations and data reduction
- 3. Results
- 4. Analysis
- 5. Shocks in the L483 protostellar jet
- 6. Continuous emission in the L483 protostellar jet
- 7. Summary
- Acknowledgements
- References
© European Southern Observatory (ESO) 1999
Online publication: July 26, 1999
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