Protostars and Planets VI, Heidelberg, July 15-20, 2013
T Tauri Jet Rotation in the Near Infrared
Coffey, Deirdre (University College Dublin, Ireland)
Dougados, Catherine (UMI LFCA Universidad de Chile, & IPAG Grenoble, France )
In recent years, there has been a number of detections of gradients in the radial velocity profile across jets from young stars. They may be interpreted as a signature of jet rotation about its symmetry axis, thereby representing observational indications supporting the theory that jets extract angular momentum from star-disk systems. However, the possibility that we are indeed observing jet rotation in pre-main sequence systems is undergoing active debate. Alternative interpretations have been proposed for these differences in radial velocity, including jet precession and asymmetric shocking. To disentangle the various effects, our group has deepened its investigation in recent years. In our latest study, we examine the jets from two T Tauri systems, RY Tau and DO Tau, using the high resolution of GEMINI/NIFS+AO. These targets have been chosen because the disk kinematics has also been investigated, using IRAM/PdBI interferometric data, and so we can test if the jet and disk rotation signatures match as they should. Furthermore, the IFU allows us to probe the jet plasma physics in high resolution close to the jet base, and search for any correlations with kinematic trends. High resolution observation of jets close to their base are critical in constraining the jet ejection mechanism (disk wind or stellar wind origin). We present preliminary results for RY Tau, via an IFU dataset of high resolution both spatially and spectrally. We report strong evidence of: 1) time variable ejection, on a scale of 2-3 years; 2) resolved shocks; 3) an upper limit of 6 km/s on the jet rotation velocity; 4) an upper limit of ≤ 0.5AU for the jet ejection radius on the disk; 5) dust depletion in the low velocity jet component.
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