Diffraction-limited 3.8 micron imaging of protostellar outflow sources

We used the new high spatial resolution observing mode of the Kitt Peak near-IR Cryogenic Optical Bench on the 4 m telescope to detect and determine the locations of the powering sources of three protostellar outflows. Diffraction limited images at 3.8 μm of the cores of AFGL 437, L1287, and NGC 7129 demonstrate that, in each case, a young stellar object - WK 34, IRAS 00338+6312, and NGC 7129 PS 1, respectively - lies at the position predicted for the outflow source on the basis of near-IR polarimetric imaging at 2.2 μm. WK 34 and NGC 7129 PS 1 display nebulosity at 3.8 μm, confirming that each illuminates an outflow cavity. These data support the hypotheses that protostellar outflows are almost always associated with very young, heavily extincted sources, that associations of outflows with pre-main sequence stars are likely to be incorrect, and that infrared polarimetric imaging is a dependable tool for probing reflection nebulae to locate embedded young stellar objects.