Gomez de Castro, Ana Ines

Contact Email: aig@eucmos.sim.ucm.es
Institute: Instituto de Astronomia y Geodesia (CSIC-UCM)
Facultad de CC Matematicas Universidad Complutense de Madrid 28040 Madrid, Spain
First Coauthor: E. Verdugo
Institute: ISO Data Center, VILSPA, ESA
Subject Area: Star Formation, Very Young Stars, T-Tauri, H-H Objects
Waveband: Ultraviolet
Technique: Spectroscopy
Presentation: Oral Contribution: Monday
Title: Wind/jet formation in T Tauri stars: theory versus UV observations
Abstract: HST-STIS observations of UV tracers of the base of protostellar jets are presented. The Si III] and CIII] profiles have been analyzed for 7 T Tauri star. As a results it is shown that: 1. High resolution profiles are instrumental for any meaningful study since the emission is produced either in the star or in the jet depending on the source. 2. The lines are not variable in short time scales (e.g. 20 minutes) pointing out that the emission is not associated with flaring activity. 3. The high densities (e.g. 1e10 cm-3) of the line formation region are confirmed. These results are compared with the theoretical predictions of magneto- centrifugal winds (disk and stellar winds). It is shown that the high densities observed cannot be reproduced by disk winds. Therefore, the semiforbidden UV lines are generated in stellar (or boundary layer) winds. In some sources, the line emission is observed at the same velocity of the optical jet pointing out a kinematical connection with it. Henceforth, for these stars, optical jets have to be initiated either from the star or the boundary layer.