Accepted to ApJ Preprint typeset using LATEX style emulateapj v. 11/26/04 VLT-CRIRES SURVEY OF ROVIBRATIONAL CO EMISSION FROM PROTOPLANETARY DISKS

We present a large, comprehensive survey of rovibrational CO line emission at 4.7 µm from 69 protoplanetary disks, obtained with CRIRES on the ESO Very Large Telescope at the highest available spectral resolving power (R=95,000, ∆v=3.2 km s−1). The CO fundamental band (∆v=1) is a well-known tracer of warm gas in the inner, planet-forming regions of gas-rich disks around young stars, with the lines formed in the super-heated surfaces of the disks at radii of 0.1–10 AU. Consistent with earlier studies, the presence of 100-1000 K CO is found to be ubiquitous around young stars which still retain disks. Our high spectral resolution data provide new insight into the kinematics of the inner disk gas. The observed line profiles are complex and reveal several different components. Pure double-peaked Keplerian profiles are surprisingly uncommon in our sample, beyond the frequency expected based on disk inclination. The majority of the profiles are consistent with emission from a disk plus a slow (few km s−1) molecular disk wind. This is evidenced by analysis of different classes as well as an overall tendency for line profiles to have excess emission on their blue side. The data support the notion that thermal molecular winds are common for young disks. Thanks to the high spectral resolution, narrow absorption lines and weak emission lines from isotopologues and fro