THE SPATIAL-DISTRIBUTION OF EXCITED H2 IN IN T TAURI - A MOLECULAR OUTFLOW IN A YOUNG BINARY-SYSTEM

Strong extended emission from molecular hydrogen in the v = 1 --> 0 S( 1) transition is mapped around T Tau. In addition, the v = 2 --> 1 S(1 ) line is detected close to the star. The ratio of the two transitions is consistent with an excitation process in which both fluorescence b y stellar ultraviolet radiation and collisions in a warm, dense medium play a role. The morphology is interpreted as emission from a molecul ar outflow which appears to wiggle as a result of the fact that T Tau is a binary system seen almost pole-on. It is shown that an outflow wi th a small opening angle can reproduce the observed extended emission. From comparison with previous studies it is argued that the molecular outflow originates from T Tau S, the infrared component. The presente d model constrains the orientation and geometry of the system.