A Hot Wind from the Classical T Tauri Stars: TW Hydrae and T Tauri

Spectroscopy of the infrared He I (λ10830) line with KECK/NIRSPEC and IRTF/CSHELL and of the ultraviolet C III (λ977) and O VI (λ1032) emission with FUSE reveals that the classical T Tauri star TW Hydrae exhibits P Cygni profiles, line asymmetries, and absorption indicative of a continuous, fast (∼400 km/s), hot (∼300,000 K) accelerating outflow with a mass loss rate ∼10–10 M⊙ yr −1 or larger. Spectra of T Tauri N appear consistent with such a wind. The source of the emission and outflow seems restricted to the stars themselves. Although the mass accretion rate is an order of magnitude less for TW Hya than for T Tau, the outflow reaches higher velocities at chromospheric temperatures in TW Hya. Winds from young stellar objects may be substantially hotter and faster than previously thought. Subject headings: stars:pre-main sequence stars: winds, outflows stars: individual (TW Hya, T Tau) infrared: stars ultraviolet: stars Harvard-Smithsonian Center for Astrophysics, Cambridge MA 02138; [email protected], [email protected] Visiting Astronomer at the Infrared Telescope Facility, which is operated by the University of Hawaii under Cooperative Agreement no. NCC5-538 with the National Aeronautics and Space Administration, Office of Space Science, Planetary Astronomy Program. Guest Investigator, Far Ultraviolet Spectroscopic Explorer– a NASA-CNES-CSA FUSE mission operated by the Johns Hopkins University; Based in part on data from the MAST Archive. University of California Observatories/Lick Observatory, Department of Astronomy & Astrophysics, University of California, Santa Cruz CA 95064; [email protected], [email protected]