Water fountains from protostars - the signposts of UV-illuminated shocked gas
Water vapor is ubiquitous in star forming regions across various mass regimes and evolutionary stages. Particularly impressive is the wealth of water lines seen toward low-mass protostars during the main accretion/ ejection phases (Class 0/I) where water traces warm and dense gas associated with the outflows and accounts for the bulk of total far-infrared line cooling.
In my talk I will show how the close connection between water and highly-excited CO as revealed by Herschel makes it possible to discriminate between different models of shocks and respective physical conditions in the protostellar environments. In particular, I will emphasize that shocks illuminated by UV photons from the accreting protostar are necessary to account for the observed low water abundance, and thus matching the far-infrared observations. In this way, Herschel has opened our eyes to the energetic lives of young stars, revealing new physical processes not previously seen from the ground.
Ostatnia aktualizacja: 17.11.2016 10:58