the shock reaction of molecular clouds to the supersonic outflows from embedded young stars is being studied. notable observable consequences include (1) extensive bipolar eruptions of cool high-momentum material surrounding or adjacent to (2) compact regions of hot shocked gas. the hot gas can be observed with iso in the lines of vibrationally-excited molecular hydrogen. strong lines are expected in the range 5-10 microns which originate from transitions within each vibrational level. none of these lines have ever been observed in interstellar gas. therefore, success here would establish a new path for investigating the nature of hot molecular gas in general. advanced shock modelling of existing data demonstrate that these are easily measurable in some objects and are of special diagnostic value. the sws would perform here individual observations of a group of four lines between 4.9 and 6 mu. the data will provide a tight link between components (1) and (2) noted above. this link has been problematic with ground-based observations especially for embedded stars. the expected higher transparency offered by iso will enable us to determine whether or not the co-deduced momentum can be jet or wind driven. this will be derived from the intrinsic power of the shock. the line ratios will inform us of how the shock operates - whether rapid heating, gradual dissociation, water cooling etc. - which could provide basic knowledge of the materials from which stars form. to this purpose, the lines and sources are chosen so that excitation temperatures and column densities can be derived extremely accurately and related to the nature of the source.
Instrument
SWS02
Temporal Coverage
1996-10-28T22:11:53Z/1996-10-29T04:15:09Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the world's first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths.
European Space Agency, 1998, Molecular Hydrogen In Bipolar Outflows: High-Vibrational Pure-Rotational Transitions, 1.0, European Space Agency, https://doi.org/10.5270/esa-twg4z1h
