Fundamental data on the desorption of pure interstellar ices

Brown, Wendy A and Bolina, Amandeep S (2007) Fundamental data on the desorption of pure interstellar ices. Monthly Notices of the Royal Astronomical Society, 374 (3). 1006 - 1014. ISSN 0035-8711

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Abstract

The desorption of molecular ices from grain surfaces is important in a number of astrophysical environments including dense molecular clouds, cometary nuclei and the surfaces and atmospheres of some planets. With this in mind, we have performed a detailed investigation of the desorption of pure water, pure methanol and pure ammonia ices from a model dust-grain surface. We have used these results to determine the desorption energy, order of desorption and the pre-exponential factor for the desorption of these molecular ices from our model surface. We find good agreement between our desorption energies and those determined previously; however, our values for the desorption orders, and hence also the pre-exponential factors, are different to those reported previously. The kinetic parameters derived from our data have been used to model desorption on time-scales relevant to astrophysical processes and to calculate molecular residence times, given in terms of population half-life as a function of temperature. These results show the importance of laboratory data for the understanding of astronomical situations whereby icy mantles are warmed by nearby stars and by other dynamical events.

Item Type: Article
Keywords: molecular data, molecular processes, methods : laboratory, ISM : molecules, TEMPERATURE-PROGRAMMED DESORPTION, ABSORPTION INFRARED-SPECTROSCOPY, MOLECULAR-HYDROGEN FORMATION, AMORPHOUS WATER ICE, THERMAL-DESORPTION, HETEROGENEOUS RECOMBINATION, GRAPHITE
Schools and Departments: School of Life Sciences > Chemistry
Subjects: Q Science
Depositing User: Deeptima Massey
Date Deposited: 21 Jul 2014 13:23
Last Modified: 24 Mar 2017 05:42
URI: http://sro.sussex.ac.uk/id/eprint/48654

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