| 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. |
