TWO MICRON MORPHOLOGY of CANDIDATE PROTOSTARS

We have conducted a near-infrared imaging survey of low-luminosity cold IRAS sources in Taurus. The sample is color and flux limited, consisting of (1) 16 optically invisible sources, probably still deeply embedded in the Taurus dark clouds and believed to be low-mass protostar candidates, and (2) eight optical T Tauri-like stars. All 24 sources were identified with near-infrared counterparts; one is entirely nebulous without a point-like source, and the others generally have an unresolved peak with or without an extended component at 2.2 μm. Thirteen of 16 invisible sources appear to be associated with infrared nebulosity. Overall, 18 of the 24 sample sources are associated with infrared and/or optical nebulosity about 1000 to 10,000 AU in size. Seven of the invisible sources show a clear bipolar or monopolar morphology, suggestive of a close relation of the nebulosity with a bipolar mass outflow. The nebulosity is most likely due to scattering of radiation from the central source by the dust associated with the mass outflow extending to the poles of a circumstellar dust disk.