 |
|
| EPoS Contribution |
|
Formation of Dense Cores in the Taurus
Molecular Cloud
Alvaro Hacar Observatorio Astronomico Nacional, Madrid, Spain | |
| We have investigated the formation of pre-stellar dense cores in the Taurus molecular cloud, the prototype of isolated, low-mass star formation. We have observed two regions, L1517 and the B213 filament, mapping both the dense cores and the surrounding gas from which the cores have condensed. We have also made use of the new understanding of core chemistry, that allows us to distinguish between gas at different evolutionary stages. From these observations, we find that the dense cores in the two regions are embedded in large, filamentary structures of gas that have kinematic properties similar to the cores, and in particular, a very low level of (subsonic) turbulence. Velocity coherence, therefore, seems not to be restricted to the interior of dense cores (sizes < 0.1 pc), as originally thought, but to dominate the intermediate-density gas over sizes close to 0.5 pc. Such a large-scale velocity pattern suggests that velocity coherence precedes core formation, and that the high density that characterizes the cores does not result from compression by gas flows, but from gravitational fragmentation of subsonic gas. | |
| Collaborators: M. Tafalla , OAN, Spain |
Suggested Session:
Chemistry,
Cores and Collapse,
Molecular Clouds |