Dynamical masses of T Tauri stars and calibration of pre-main-sequence evolution

We have used the high sensitivity and resolution of the IRAM interferometer to produce subarcsecond (CO)-C-12 J = 2-1 images of nine protoplanetary disks surrounding T Tauri stars in the Taurus-Auriga cloud (seven singles and two binaries). The images demonstrate the disks are in Keplerian rotation around their central stars. Using the least-square Dt method described in the 1998 work by Guilloteau & Dutrey, we derive the disk's properties, in particular its inclination angle and rotation velocity, hence the dynamical mass. Since the disk mass is usually small, this is a direct measurement of the stellar mass. Typically, we reach an internal precision of 10% in the determinations of stellar mass. The overall accuracy is limited by the uncertainty in the distance to a specific star. In a distance-independent way, we compare the derived masses with theoretical tracks of pre-main-sequence evolution. Combined with the mean distance to the Taurus region (140 pc), for stars with mass close to 1 M-circle dot, our results tend to favor the tracks with cooler photospheres (higher masses for a given spectral type). We find that in UZ Tau E, the disk and the spectroscopic binary orbit appear to have different inclinations.