Shocked molecular hydrogen from RNO 91

We report the detection of the H2 v=1-0 S(1) line at 2.122μm, from RNO91 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 RNO91 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 ′′ × 3 is estimated to be 7× 10 ergs seccm, which indicates a mass flow rate of 4×10 M⊙ 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.