MEASUREMENT OF CO OVERTONE LINE-PROFILES IN SVS-13

We have obtained high-resolution spectra of the CO overtone emission in the infrared source SVS 13 and have resolved the individual vibration-rotation lines for the first time in a young stellar object. The observed FWHM velocity of the lines in the v = 2-0 band is 40 km s-1. A fit of the v = 2-0 band head with a single temperature LTE slab model yields an optical depth of 0.3 in the R(51) line and a rotational temperature of about 3500 K. Given the best estimates for the orientation of the SVS 13 outflow, the observed line widths are much smaller than expected for either of the two most favored interpretations for the CO emission: a circumstellar disk or a high-velocity neutral wind.