title: Grain formation modulated by molecular hydrogen evaporation in the interstellar medium.
abstract: A mechanism for grain growth and formation in the interstellar medium is proposed. In this mechanism, hydrogen molecules act as moderators. The process begins when they physisorb to the surface of the grain. Then, when a collision with a heavy atom occurs, the bonding energy is carried away by the evaporation of hydrogen molecules. Estimates are made of the number of hydrogen molecules bound to the surface of a grain that would be sufficient to facilitate this mechanism at 13 K for amorphous carbon and 8 K for a silicate grain.
authors.affiliation: Department of Chemistry and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA.
authors.forename: A
authors.initials: A
authors.lastname: Reber
authors.forename: K S
authors.initials: KS
authors.lastname: Kostov
authors.forename: R S
authors.initials: RS
authors.lastname: Berry