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A HOT WIND FROM TW HYA: IMPLICATIONS FOR X-RAYS IR and Ultraviolet (FUSE) spectroscopy Hot (300,000K), Fast ( 100’s km/s) wind Structures in wind Most probably from star itself Andrea Dupree and Nancy Brickhouse, CfA Star Formation and Great Observatories: 13 July 2005 TW Hya: Perfect orientation to seek a wind….. Accretion Disk face-on (Krist et al 2000) Star and its magnetic dipole almost ‘pole-on’ In the Sun, open magnetic fields allow corona to escape in the fast solar wind… TW Hya: He I (λ10830) indicates fast, warm wind He I IR line a sensitive marker of mass flow: metastable level is decoupled from local conditions. NIRSPEC/KECK spectra show P Cygni profile with wind extension to -250 to -300 km/s Far UV Spectra indicate hotter wind FUSE spectra show C III wind absorption to -350 km/s (80,000K) O VI profile is also asymmetric.. (300,000K) Dupree et al. 2005, ApJ, 625, L131 Profiles of High Temperature Lines Indicate Wind Absorption Asymmetry typical of wind absorption occurs in strong resonance lines of C III (977A) and O VI (1032A) measured with FUSE. (Similar asymmetries found in HST/STIS profiles of C IV and N V.) Absorption revealed with Gaussian fit to line profile Accelerating wind detected in TW Hya Absorption profile reveals accelerating wind with increasing temperature: He I 260 km/s 20,000K C III 325 km/s 80,000K O VI 440 km/s 300,000K For τSobolev ~ 1, Mass loss = 10-12 to 10-11 M~/yr Smaller than ‘accretion rate’ Wind is constant, exhibits structures Variability on the ‘red’ side (accretion side) of H-alpha and O VI. Structure apparent on ‘blue’ (wind) side of profiles of H-alpha. H-alpha from Magellan/MIKE O VI from FUSE Structure apparent in outflow Magellan/MIKE H-alpha spectra over 2 epochs suggest periodicity. KECK/NIRSPEC spectra indicate wind variations at higher temperatures. Dupree & G. Smith, 2005, in prep. CONCLUSIONS/IMPLICATIONS Hot winds (80000K300,000K) are present in accreting T Tau stars Continuously increasing T and acceleration from star Appear to originate from star itself May provide link to optical jets Broad uv lines suggest source of uv distinct from x-rays Wind can affect angular momentum loss