Discovery of a Bipolar Outflow from 2MASSW J1207334-393254, a 24 M Jup Brown Dwarf

The 24 M Jupiter mass brown dwarf 2MASS1207-3932 has for some time been knownto show clear signs of classical T Tauri-like accretion. Through analysis ofits oxygen forbidden emission we have discovered that it is driving a bipolaroutflow. Blue and red-shifted components to the [OI] 6300 forbidden emissionline are seen at velocities of - 8 km/s and +4 km/s. Spectro-astrometryrecovers the position of both components relative to the BD, at ~ 0.08arcseconds(in opposing directions). A position velocity diagram of the lineregion supports the spectro-astrometric results. The H-alpha and HeI 6678 lineswere also analysed. These line regions are not offset with respect to thecontinuum ruling out the presence of spectro-astrometric artifacts andunderlining the validity of the [OI] 6300 results. The low radial velocity ofthe outflow, and relatively large offsets, are consistent with 2MASS1207-3932having a near edge-on disk, as proposed by Scholz et al. 2MASS1207-3932 is nowthe smallest mass galactic object known to drive an outflow. The age of the TWHydrae Association (~ 8 Myr) also makes this one of the oldest objects with aresolved jet. This discovery not only highlights the robustness of the outflowmechanism over an enormous range of masses but also suggests that it may evenbe feasible for young giant planets with accretion disks to drive outflows.Comment: 12 pages, 2 figure