THE INFRARED NEBULA AND OUTFLOW IN LYNDS-483

Near-infrared and submillimeter observations of IRAS 18148-0440 in the Lynds 483 dark cloud are presented. The near-infrared images show nebulous emission extending up to similar to 60'' from the IRAS position. The IRAS source is not directly detected at any wavelength and is obscured by more than 70 mag of visual extinction, Submillimeter continuum measurements indicate the presence of similar to 0.3 M. of material within about 1900 AU of the central star. At 2.2 mu m the near-infrared nebula is bipolar with approximately cylindrical lobes which extend east and west of the IRAS source and coincide with the bipolar lobes of the CO outflow from the source. The western lobe of the nebula is significantly brighter than the eastern lobe and is spatially coincident with the blueshifted CO emission from the outflow. If the nebular lobes have equal intrinsic brightness, their apparent brightness implies that the outflow has an inclination angle of similar to 40 degrees to the plane of the sky and that the density distribution within the dense gas around IRAS 18148-0440 has a radial profile steeper than r(-1). There is a bright knot of molecular hydrogen emission close to the end of the blueshifted CO with a jet like feature extending from the knot back toward the location of the embedded star. The knot of emission is thought to be tracing the region where the stellar wind is impacting the surrounding dense gas. The observations suggest that IRAS 18148-0440 is very young and that its outflow is driven by a jet from the central star.