IRAS 11590-6452 in BHR 71: A Binary Protostellar System?

Abstract

New Anglo-Australian Telescope near-infrared and Swedish-ESO Submillimetre Telescope ¹²CO J=2-->1 observations are combined with existing Infrared Space Observatory mid-infrared and Australia Telescope Compact Array centimeter radio continuum observations to examine the protostellar content of the Bok globule BHR 71. Together with observations of Herbig-Haro objects, these data show the following: (1) Two protostellar sources, IRS 1 and IRS 2, with a separation of ~17" (3400 AU) are located within BHR 71. (2) Each protostar is driving its own molecular outflow. The outflow from IRS 1 is much larger in extent, is more massive, and dominates the CO emission. (3) Both protostars are associated with Herbig-Haro objects and shock-excited 2.122 μm H₂ v=1-0 S(1) emission, which coincide spatially with their CO outflows. (4) IRS 1 is associated with centimeter continuum emission, with a flat or rising spectrum, which is consistent with free-free emission, a signpost of protostellar origin.