Mass loss in T Tauri stars - Observational studies of the cool parts of their stellar winds and expanding shells

摘要: Extensive high-resolution (..delta nu.. = 12 km s/sup -1/ FWHM) and high signal-to-noise ratio (S/N) line profile measurements of 25 T Tauri stars have been obtained using the Arizona/Smithsonian Multiple Mirror Telescope echelle spectrograph, photon counting Reticon. In order to investigate cooler regions these stars, expanding envelopes, most profiles were Na D lines. Indications mass loss in Ca II H K lines found 11 stars. These show considerably stronger permitted forbidden emission than with negative detections. eight surprisingly narrow (10 -1/< or FWHM< =50 -1/), blueshifted absorptions observed lines, which some cases not variable radial velocity over up 2 years nu..<3 -1/). P Cygni broad absorption components (100 =FWHM< =250 -1/) four