| Description |
Outflows play a crucial role in star formation, since they carry away
angular momentum from the protostars that drive them, allowing
accretion to continue and the protostars to grow. They also represent
a fossil record of the mass loss from their young hosts, providing
valuable insights to the processes that govern accretion and outflow.
Though jets and molecular outflows have been the subject of much
scrutiny, the mechanisms responsible for launching and collimating
the gas are still unclear and the relationship between the narrow optical
jets and larger molecular outflows they accompany has still to be
determined.
In order to understand the vital role of outows in star formation, a
detailed characterization of their physical, chemical and kinematical
properties is essential. Accurate values for the mass, mass transport
rate and momentum in outows can then be derived to test competing
formation scenarios, and the shock conditions can be determined. The
HH111 jet and associated molecular outflow and CO bullets represent
an excellent prototype of these outflow phenomena in which to
accomplish this. We therefore propose to obtain a complete physical,
chemical and kinematical picture of the hot molecular gas in the
HH111 jet with Herschel by performing HIFI observations of selected
CO rotational lines, SPIRE FTS mapping spectroscopy of the outflow
region and SPIRE and PACS photometric maps of the same region.
Together, these observations will enable a comprehensive study of
the molecular gas and dust contained in the HH111 outflow, allowing
an unparalleled determination of its physical properties and the role
it plays in the mass loss from the central protostar. This, in turn, will
give key insights into the mechanisms that power outflow phenomena
in general. |
