Microscopic simulations of laboratory and interstellar ice structure and chemistry. Issue Volume 15:Issue S350(2019) (April 2019)

• Record Type: Journal Article
• Authors: Garrod, Robin T.; Clements, Aspen R.
• Editors: Salama, Farid; Linnartz, Harold
• Is Part Of: Proceedings of the International Astronomical Union. Volume 15:Issue S350(2019)
• Page Start: 429
• Page End: 430
• Publication Date: 2019-04
• Subjects: ISM: molecules, -- ISM: dust, -- methods: numerical, -- methods: laboratory; Astronomy -- Congresses; Astronomy -- Periodicals; 520
• DOI: 10.1017/S1743921319009414
• Languages: English
• ISSNs: 1743-9213

Abstract

Abstract: We describe recent simulations of interstellar and laboratory ices using the 3-D, off-lattice microscopic Monte Carlo kinetics model MIMICK . The simulations indicate that interstellar ices are capable of achieving porous structures, dependent on physical conditions. In some cases, such structures may be filled as they are formed, by mobile/volatile species such as H2 that become trapped in those structures. Simulations of laboratory water-ice deposition using MIMICK suggest that an additional non-thermal diffusion mechanism is required to reproduce the high degree of porosity achieved for experimental ices at temperatures less than ~80 K. This mechanism is related to the deposition process itself. Simulations of temperature-programmed desorption of mixed molecular ices are ongoing. The interstellar models have also recently been developed to incorporate a full gas-phase chemistry, coupled with the grain-surface chemistry.