A single distance sample of molecular outflows from high-mass young stellar objects
Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Egerton Wharf, Birkenhead CH41 1LD, UK
2 : FCRAO, 619 Lederle Graduate Research Center, University of Massachusetts, Amherst, MA 01003, USA
Corresponding author: N. A. Ridge, email@example.com
Accepted: 22 August 2001
We have made 12CO 2-1 and 1-0 maps of eleven molecular outflows associated with intermediate to high-mass young stellar objects (YSOs) in order to establish whether the correlations between outflow parameters and source bolometric luminosity hold in the high-mass regime. It is important to consider the effects of Malmquist-type biases when looking at high-mass YSOs, as they are generally much more distant than their low mass counterparts. We therefore chose only objects located at ~2 kpc. We find that the relations show much more scatter than is seen in similar studies of low-mass YSOs. We also find that the mass-spectrum is significantly steeper in high-mass outflows, indicating a larger mass-fraction at lower velocities, a low collimation factor (~1-2) and no Hubble-like relationship.
Key words: stars: formation / stars: winds, outflows / ISM: jets and outflows / ISM: molecules
© ESO, 2001