we propose high resolution spectroscopic observations with the iso satellite toward a number of unexplored southern star-forming regions in order to determine their physical and chemical state. the chemical composition of the gas is strongly influenced by interaction with the dust, and is an excellent probe of the evolutionary stage of the object. key molecules for observations are co2, h2o, oh, c2h2, ch3 and ch4, none of which can be observed from the ground from a southern hemisphere site. the data will provide insight into the amount of grain surface processing and the atomic hydrogen, carbon and/or oxygen content of the initial collapsing cloud. the excitation temperatures of the molecules will provide clues to the mechanism for returning molecules from the grains to the gas (thermal evaporation vs shock disruption of icy mantles). detailed chemical modeling should allow accurate constraints on the time scales associated with these processes. together with complementary iso observations of solid state features proposed by others and our existing ground-based (sub)millimeter data, these observations will provide a unique data set of both the gas and the dust component for the same line of sight for a number of star forming regions.
Instrument
SWS06 , SWS07
Temporal Coverage
1996-03-11T18:18:25Z/1996-03-18T08:59:22Z
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, 1999, The Chemical State Of Southern High-Mass Star-Forming Regions, 1.0, European Space Agency, https://doi.org/10.5270/esa-7z9qkac
