A molecular outflow driven by the brown dwarf binary FU Tauri*

We report the detection of a molecular outflow driven by the brown dwarf binary FU Tau. Using the IRAM 30 m telescope we observed the 12CO(2−1) (CO) emission in the vicinity of FU Tau and detected a bipolar outflow by examining the wings of the CO(2−1) line as we moved away from the source position. An integrated map of the wing emission between 3 km s-1 and 5 km s-1 reveals a blueshifted lobe at a position of ~20′′ from the FU Tau system and at a position angle of ~20°. The beam size of the observations is 11″, so it is not possible to distinguish between the two components of the FU Tau binary. Since optical forbidden emission, a strong tracer of the shocks caused by outflow activity, has been detected in the spectrum of FU Tau A, we assume that this component is the driving source of the molecular outflow. We estimate the mass of the outflow at 4 × 10-6M⊙ and the mass outflow rate at 6 × 10-10M⊙/yr. These results agree well with previous estimates for BD molecular outflows. FU Tau A is now the third BD found to be associated with molecular outflow activity, and this discovery adds to the already extensive list of the interesting properties of FU Tau