Plateau de Bure interferometer observations of the disk and outflow of HH 30

Abstract

HH30 is a well-known Pre-Main-Sequence star in Taurus. HST observations have revealed a flared, edge-on disk driving a highly-collimated optical jet, making this object a case study for the disk-jet-outflow paradigm. We obtained high angular resolution (about 1") observations of the dust continuum at 2.7 and 1.3 mm, and of the 12CO(2-1), 13CO(2-1) & (1-0), C18O(1-0) emissions around HH30. A standard disk model is used to fit the 13CO(2-1) uv-plane visibilities and derive the disk properties, and the stellar mass. It results that HH30 is a low mass TTauri of spectral type around M1 and age 1 to 4 Myrs, surrounded by a medium size Keplerian disk, of mass around 4e-3 Msun and outer radius 420 AU. The disk rotation vector points toward the North-Eastern jet. Using a distance of 140 pc, we deduce a stellar mass of 0.45 Msun. A highly asymmetric outflow originates from the inner parts of the disk. It presents to first order a conical morphology with a 30 degree half opening angle and a constant (12 km/s) radial velocity field. Outflow rotation was searched for but not found. These observations do not enable to assign the origin of the molecular outflow to entrainment by the optical jet or to a disk wind. In the latter case, the upper limit of the outflow rotation velocity implies an origin in the inner 15 AU of the disk.