The high-velocity molecular flows near young stellar objects
Abstract
The results of a search for high-velocity molecular gas associated with star forming molecular clouds are reported. Faint, high-velocity (ΔV ≥ 30 km s-1)12CO emission is frequently found near buried infrared sources. In most clouds, the high-velocity gas is observed over an extended area having a typical radius around 1018 cm and exhibits bipolar structure with the redshifted emission formed in a different region from the corresponding blueshifted emission. Analysis of the CO line emission indicates that typical flows have masses in the range M ≈ 0.3 - 100 M_sun;, velocities in the range V ≈ 10 - 50 km s-1, and lifetimes as distinctly recognizable dynamical entities of around t ≈ 104 yr. The kinematics of the high-velocity gas are best explained as outflows from the vicinity of the associated infrared sources. However, it appears that the ionized stellar winds proposed to explain infrared line and radio continuum observations toward many of these sources cannot be driving the energetic molecular flows. The presence of high-velocity outflow in molecular clouds indicates an unanticipated phase of energetic mass loss associated with the birth and early evolution of stars.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 1983
- DOI:
- 10.1086/160729
- Bibcode:
- 1983ApJ...265..824B
- Keywords:
-
- Carbon Monoxide;
- Interstellar Gas;
- Molecular Flow;
- Stellar Evolution;
- Stellar Winds;
- Early Stars;
- Gas Flow;
- Infrared Radiation;
- Mass;
- Molecular Clouds;
- Spectral Line Width;
- Velocity Distribution;
- Astrophysics