摘要:
We present survey results that suggest rotation signatures at the base of T Tauri jets. Observations were conducted with the Hubble Space Telescope Imaging Spectrograph at optical and near-ultraviolet (NUV) wavelengths. Results are presented for the approaching jet from DG Tau, CW Tau, HH 30, and the bipolar jet from TH 28. Systematic asymmetries in Doppler shift were detected across the jet, within 100 AU from the star. At optical wavelengths, radial velocity differences were typically ± 5 km s -1, while differences in the NUV range were consistently lower, at typically 10 ± 5 km s-1. Results are interpreted as possible rotation signatures. Importantly, there is agreement between the optical and NUV results for DG Tau. Under the assumption of steady magnetocentrifugal acceleration, the survey results lead to estimates for the distance of the jet footpoint from the star, and give values c
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