Efficiency of Molecular Hydrogen Formation on Silicates

Abstract

We report on laboratory measurements of molecular hydrogen formation and recombination on an olivine slab as a function of surface temperature under conditions relevant to those encountered in the interstellar medium. On the basis of our experimental evidence, we recognize that there are two main regimes of H coverage that are of astrophysical importance; for each of them we provide an expression giving the production rate of molecular hydrogen in interstellar clouds.

Accepted for publications in: Astrophysical Journal Letters. Corresponding author: Gianfranco Vidali: [email protected] (http://physics.syr.edu/research/surface_physics/)