MAGNETOSPHERIC ACCRETION MODELS FOR T-TAURI STARS .1. BALMER LINE-PROFILES WITHOUT ROTATION

We argue that the strong emission lines of T Tauri stars are generally produced in infalling envelopes. Simple models of infall constrained to a dipolar magnetic field geometry explain many peculiarities of obs erved line profiles that are difficult, if not impossible, to reproduc e with wind models. Radiative transfer effects explain why certain lin es can appear quite symmetric while other lines simultaneously exhibit inverse P Cygni profiles, without recourse to complicated velocity fi elds. The success of the infall models in accounting for qualitative f eatures of observed line profiles supports the proposal that stellar m agnetospheres disrupt disk accretion in T Tauri stars, that true bound ary layers are not usually present in T Tauri stars, and that the obse rved ''blue veiling'' emission arises from the base of the magnetosphe ric accretion column.