1999A&A...344L...9N

We report the detection of the H₂ v=1-0 S(1) line at 2.122µm, from RNO 91 in the L43 dark cloud, which is known to be a T Tauri star surrounded by a 1700AU disk structure (containing ices) and a weak outflow. The non-detection of the H₂ v=2-1 S(1) line at 2.247µm suggests shock excitation rather than fluorescence. The emission is extended spatially up to 9" in the north-south direction. The line intensity peak (FWHM∼3") corresponds to the star RNO 91 which is embedded in a cocoon of gas and dust. The observed H₂ emission from this cocoon may be attributed to embedded Herbig-Haro like knots. The H₂ line flux in the central 2"x3" is estimated to be 7x10^–14ergs/s/cm², which indicates a mass flow rate of 4x10^–8M_☉/yr. Furthermore, narrow band image taken through H₂ 1-0 S(1) filter is presented, which reveal a tilted disk and bipolar outflow structure that agrees with earlier observations and models. We show that this disk/outflow system is a unique case.