astronomical observational studies are proposed to determine the composition, abundance, distribution, and evolution of organic molecules (namely aliphatic hydrocarbons and nitriles) on dust grains in the interstellar medium. the ultimate goal is to understand the processes involved in the formation of these prebiogenic compounds, their chemical evolution, and the relationship between the compounds in the diffuse and dense interstellar clouds. a significant step toward this goal can be achieved by measuring the infrared spectrum in the 4500-500 cm-1 (2.0-20.0 um) region in astronomical objects which span the evolutionary range from diffuse clouds through quiescent dense molecular clouds. this proposal will only focus a subset of these observations, which will complement ongoing ground-based and airborne (kuiper airborne observatory) studies. the objective for this proposal is to study the diffuse ism dust with iso observations over two wavelength regions that either cannot be studied from the ground at all (4.05 - 4.5 um) or sufficiently well (3.2- 3.4 um). the observations proposed target three spectral regions that are essential to understanding the distrbution of carbon among nitriles and hydrocarbons. the three carbonbearing compounds of interest are nitriles (4.35 - 4.45 um), polycyclic aromatic hydrocarbons in absorption (3.3 um), and the related c-d stretch (4.1 - 4.3 um). ground based studies of the aliphatic hydrocarbon (3.4 um) and isonitrile (4.62um) absorption features in diffuse and dense clouds,respectively, are currently underway.the portions of the spectrum that we cannot look at from the ground may hold important keys to the overall distribution of carbon among these several types of organic materials.
Instrument
SWS01 , SWS06
Temporal Coverage
1996-03-30T15:01:16Z/1997-03-15T17:55:53Z
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 Organic Component Of Interstellar Dust In Diffuse Clouds, 1.0, European Space Agency, https://doi.org/10.5270/esa-02kqwrb
