2000A&A...357L..61D

Using adaptive optics techniques, we have obtained the first [O I] and [S II] images at 0.1" (≃15AU) resolution of the jets in CW Tau, DG Tau and RW Aur. In all three jets, the emission is dominated by knots and is resolved transversally down to 56AU with similar inner jet widths of 0.2-0.25". The RW Aur and CW Tau jets are straight, their FWHM slowly increasing with distance with opening angles of ≃3-4°. In contrast, the DG Tau jet seems to be precessing and its FWHM reaches 1.3" at 335AU, where contamination by strong bow-shock wings most likely occurs. The widths of the CW Tau and RW Aur jets are strikingly similar to those measured in HH 30 and HL Tau, two active TTs, on similar spatial scales. The derived upper limit on the density collimation size scale of ≃50AU and intrinsic jet widths of ≃30AU over the central 100AU are in quantitative agreement with predictions from current MHD wind models. In DG Tau we confirm the bow-shaped morphology and detect a high proper motion (194km/s) for the knot located at 3.3". The properties of this knot strongly support the model of internal working surfaces produced by variable ejection.