Organics and Ices in Galactic Dust
Hydrocarbon absorption (3.4 μm) along several different sightlines through the galaxy indicates that the dust carrier lies in the diffuse interstellar medium (DISM). Correlations of the hydrocarbon and silicate absorption features suggest an increased abundance of both in the direction of the galactic center. Dense molecular clouds do not exhibit the same type of 3.4 μm feature as seen in the DISM, which is puzzling in light of dust cycling times. Laboratory organics produced by different processes are compared to the DISM features. The 3.4 μm feature has now been detected in other galaxies, which suggests that the widespread distribution of organic material in our own galaxy may be common to other galaxies as well.
KeywordsInterstellar Medium Molecular Cloud Galactic Center Dense Cloud Interstellar Dust
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