HST/STIS Spectroscopy of the Optical Outflow from DG Tau: Indications for Rotation in the Initial Jet Channel

摘要: We have carried out a kinematical, high angular resolution (~ 0".1) study of the jet from DG Tau within 0."5 source (or 110 AU along this flow). analysed line profiles extracted set seven spectra taken with STIS on board Hubble Space Telescope, slits parallel to axis but displaced transversely every 0".07. For flow moderate velocity (-70 km/s), we found systematic differences in radial velocities lines emitted alternate sides axis. The results are corrected for effects due uneven illumination slit. relative Doppler shifts range 5 20 km/s. If is interpreted as rotation, then rotating clockwise looking towards and derived toroidal 6 - 15 Using recent estimates mass loss rate, one obtains considered regime, an momentum flux ~ 3.8x10E-5 M_sun/yr Our findings may constitute first detection rotation initial channel flow. values appear be consistent predictions popular magneto-centrifugal jet-launching models, although cannot exclude transverse outflow asymmetries other than rotation.