we propose to make high quality observations of the 2.75 micron feature of interstellar hydrated silicates which has been recently discovered by iso towards cyg.ob2 #12. a number of sources suffering from extinction by the diffuse interstellar medium are selected. together with guaranteed time data of dense clouds sources and of mass-loosing giant stars our program could reveal the importance of hydration for grains in various interstellar environments. this information could yield important clues on the origin and evolution of interstellar silicates, i.e., whether cold formation in the interstellar medium or hot formation in the outflow of stars dominate. showing considerable variation in different materials, comparison of high quality spectra of the hydration band with laboratory analog materials could furthermore clarify the composition of interstellar minerals.
Instrument
SWS06
Temporal Coverage
1997-02-20T23:19:40Z/1997-03-28T18:41:42Z
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.
