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

By F. Bacciotti, T. Ray, R. Mundt, J. Eisloeffel, J. Italy, Dublin ▪ Ireland, M. F. A. -. H. Germany, Thueringer Landessternwarte - Tautenburg - Germany. 2002

248 citations recorded by the source corpus.

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

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/0e5a58fd136649e3bd2b3a7632fd5243a00f9913

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Citations in the corpus

Accretion-powered Stellar Winds. II. Numerical Solutions for Stellar Wind Torques (2008, background): “…due to the large linear momenta of the outflows (Königl & Pudritz 2000), the X-ray luminosities (Decampli 1981), and possible detection of rotation (Bacciotti et al. 2002; Anderson et al. 2003; Coffey et al. 2004; Ferreira et al. 2006; Coffey et al. 2007), it appears that most of the flow arises…”
On the Evolutionary Status of Class I Stars and Herbig-Haro Energy Sources in Taurus-Auriga (2004, background): “We note that the inferred measured mass outflow rates are slightly larger than, by a factor of 3, the values determined from high spatial resolution spectroscopy (e.g., Bacciotti et al. 2002; Woitas et al. 2002).”
Rotation of Jets from Young Stars: New Clues from the Hubble Space Telescope Imaging Spectrograph (2003, methodology): “This resulted in a displacement of the peak intensity of up to 0′′.02, a quantity which would produce a marginal asymmetry in radial velocity estimated to be at most 20% if uncorrected (Bacciotti et al. 2002).”
Photoevaporation of Circumstellar Disks around Young Stars (2004, background): “However, recent high resolution observations suggest that the low-velocity component probably originates at ‘large’ disk radii (e.g., Bacciotti et al. 2002; Anderson et al. 2003), suggesting that some other mechanism is responsible for the observed lowvelocity component.”
Accretion-powered Stellar Winds as a Solution to the Stellar Angular Momentum Problem (2005, unknown): “Thus, CTTS winds should rotate at a speed comparable to that of a disk wind (Bacciotti et al. 2002; Anderson et al. 2003) at observationally resolved distances from the star.”
Magnetospheric accretion-ejection processes in the classical T Tauri star AA Tauri (2006, background): “They arise in a region very close to the star and were observed with ground based adaptive optics (Dougados et al. 2000) and HST (Bacciotti et al. 2002), providing unprecedent information on the dynamics near the base of the jet, where the wind is formed.”
Outflows and Jets from Collapsing Magnetized Cloud Cores (2005, background): “The predicted properties for the jets, namely that they rotate and transport the bulk of the disk’s angular momentum, have now been confirmed by Hubble Space Telescope observations (Bacciotti et al. 2002).”
MHD simulations of jet acceleration from Keplerian accretion disks - The effects of disk resistivity (2007, background): “12), a quantitative comparison with the poloidal speed (Bacciotti et al. 2000) and rotation signatures (Bacciotti et al. 2002; Coffey et al. 2004; Woitas et al. 2005) of the observed outflows is much more difficult, because the size of our computational domain, which reaches a physical scale along…”
Protostellar disk formation and transport of angular momentum during magnetized core collapse (2012, background): “…the very beginning of protostar evolution to the T Tauri stage, they are thought to be launched by magneto-centrifugal means (Blandford & Payne 1982; Pudritz & Norman 1983, Uchida & Shibata 1985), and may play an important role in the efficient transport of angular momentum (Bacciotti et al. 2002).”
Theory of Star Formation (2007, background): “Recent high-resolution observations have detected signatures of differential rotation in jets, using near-UV, optical, and near-IR lines (Bacciotti et al., 2002; Ray et al., 2007); these also indicate a range of wind launch points.”
Magnetic tower outflows from a radial wire array Z-pinch (2005, background): “Recent observations of rotation in jets on ~ AU scales have provided new evidence for these models (Bacciotti et al. 2002; Coffey et al. 2004).”
Which jet launching mechanism(s) in T Tauri stars (2006, methodology): “Detections of transverse velocity shifts suggestive of rotati n signatures have been recently derived from HST/STIS spectra at distances≃ 50 AU from the central source in 4 T Tauri microjets: DG Tau, Th 28, LkHα 321, and RW Aur (Bacciotti et al. 2002; Coffey et al. 2004; Woitas et al. 2005).”