Proper motion measurements in the HH 34 jet and its associated bow shocks.
Abstract
Extensive measurements are presented of the proper motions of knots in the HH34 jet and the bow shocks of the HH34 system, which is a prototype for a jet system of a young star. The results show that all the knots in the system are moving, with typical tangential velocities on the order of 150-300 km/s 1 the jet and typical value of 200-400 km/s in the bow shocks. The ratio between the pattern speed of the knots and the flow speed of the jet particles is found to be 0.5-1.0 and to increase from the source toward HH34S. The observed proper motions clearly exclude any stationary jet model. Jet models explaining the knots as due to Kelvin-Helmholtz instabilities can in principle account for both the large motion and observed zeta values of the knots. The observed variations the spatial velocity of the jet are attributed to time variations in the jet source on timescales of 50-0500 yrs, which are among that largest that have been observed in young stars.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- September 1992
- Bibcode:
- 1992A&A...263..292E
- Keywords:
-
- Bow Waves;
- Early Stars;
- Herbig-Haro Objects;
- Shock Wave Propagation;
- Stellar Motions;
- Astronomical Models;
- Jet Flow;
- Molecular Flow;
- Radial Velocity;
- Astrophysics