منابع مشابه
Evolution of interstellar ices.
Infrared observations, combined with realistic laboratory simulations, have revolutionized our understanding of interstellar ice and dust, the building blocks of comets. Ices in molecular clouds are dominated by the very simple molecules H2O, CH3OH, NH3, CO, CO2, and probably H2CO and H2. More complex species including nitriles, ketones, and esters are also present, but at lower concentrations....
متن کاملDesorption From Interstellar Ices
The desorption of molecular species from ice mantles back into the gas phase in molecular clouds results from a variety of very poorly understood processes. We have investigated three mechanisms; desorption resulting from H2 formation on grains, direct cosmic ray heating and cosmic ray induced photodesorption. Whilst qualitative differences exist between these processes (essentially deriving fr...
متن کاملSynthesis of prebiotic glycerol in interstellar ices.
Contemporary mechanisms for the spontaneous formation of glycerol have not been able to explain its existence on early Earth. The exogenous origin and delivery of organic molecules to early Earth presents an alternative route to their terrestrial in situ formation since biorelevant molecules like amino acids, carboxylic acids, and alkylphosphonic acids have been recovered from carbonaceous chon...
متن کاملFormation of Interstellar Ices behind Shock Waves
We have used a coupled dynamical and chemical model to examine the chemical changes induced by the passage of an interstellar shock in well shielded regions. Using this model we demonstrate that the formation of H2O in a shock will be followed in the post–shock phase by depletion of the water molecules onto the grain surfaces. To attempt to discriminate between the creation of ices behind shock...
متن کاملCosmic Ray Compaction of Porous Interstellar Ices
We studied the compaction of microporous vapor-deposited ice films under irradiation with different ions in the 80Y400 keVenergy range.We found that porosity decreases exponentially with irradiation fluence, with amean compaction area per ion that scales linearlywith the stopping power of the projectile S above a threshold St 1⁄4 4 eV8 . The experiments roughly follow a universal dependence of ...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 2013
ISSN: 1365-2966,0035-8711
DOI: 10.1093/mnras/sts601