WISHes coming true: low-mass protostars as chemical fountains
Abstract
Water is a key molecule for tracing the chemical and physical processes taking place during the formation of low-mass stars in the Galaxy. Water is a unique molecule for tracing all physical components of a star-forming object: cold quiescent gas in the outer envelope, warm gas in the inner turbulent envelope, the molecular jet, shocks along the outflow cavity walls and UV-heated cavity walls. The "Water in star-forming regions with Herschel" (WISH; van Dishoeck et al. 2011) program uses a combination of high spectral and spatial resolution observations of water and related molecules to study each component and its associated chemistry. The chemistry is directly reflected in the physical processes listed above: molecule formation on grain mantles, non-thermal and thermal desorption from grain surfaces to the gas phase, molecule survival, destruction and reformation under extreme shock conditions and photo-dissociation and -chemistry. Recent results from WISH will be presented here. These include a detailed comparison of the properties of water across the entire sample of some 30 low-mass young stellar objects observed, and reveal how the chemistry and physics couple over a wide range of temperatures and densities. A comparison will also be made to other chemical tracers, such as CH3OH, a well-known grain-surface product. Interpreting these data requires a combination of state-of-the-art chemical and physical models. New advances in the 2D modeling, interpretation and understanding of the densest parts of the interstellar medium surrounding protostars will be highlighted.
- Publication:
-
The Molecular Universe
- Pub Date:
- May 2011
- Bibcode:
- 2011IAUS..280E..10K