2003/12/11 by Deirdre Coffey, F. Bacciotti, Francesca Bacciotti +6 · 2 citations
Physics and Astronomy · #Astro and Planetary Science #Astrophysics and Star Formation Studies #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/382019
published as Astrophys.J. 604 (2004) 758-765 · 17 pages, 10 figures, Accepted by ApJ
arxiv created 2003/12/11 · openalex publication_date 2004/03/26 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/04
We report findings from the first set of data in a current survey to establish conclusively whether jets from young stars rotate. We observed the bipolar jets from the T Tauri stars TH 28 and RW Aur and the blueshifted jet from T Tauri star LkHα 321, using the Hubble Space Telescope Imaging Spectrograph. Forbidden emission lines show distinct and systematic velocity asymmetries of 10-25 (±5) km s -1 at a distance of 0 3 from the source, representing a (projected) distance of ≈40 AU along the jet in the case of RW Aur, ≈50 AU for TH 28, and 165 AU in the case of LkHα 321. These velocity asymmetries are interpreted as rotation in the initial portion of the jet where it is accelerated and collimated. For the bipolar jets, both lobes appear to rotate in the same direction. Values obtained were in agreement with the predictions of MHD disk-wind models. Finally, we determine, from derived toroidal and poloidal velocities, values for the distance from the central axis of the footpoint for the jet's low-velocity component of ≈0.5-2 AU, consistent with the models of magnetocentrifugal launching.