2014/03/20 by L. Reboussin, Laura Reboussin, Valentine Wakelam +4 · 3 citations
Chemistry · Physics and Astronomy · #Advanced Chemical Physics Studies #Astrochemistry #Astrophysics #Astrophysics and Star Formation Studies #Chemical physics #Chemistry #Condensed matter physics #Cosmic dust #Cosmic ray #Diffusion #Galaxy #Interstellar medium #Molecular Spectroscopy and Structure #Molecule #Particle (ecology) #Physical chemistry #Physics #Quantum mechanics #Quantum tunnelling #Surface (topology) #Surface diffusion #Thermal #Thermal fluctuations #Thermodynamics #astro-ph.GA
paper · pdf · doi:10.1093/mnras/stu462
12 pages, 24 figures
arxiv created 2014/03/20 · openalex publication_date 2014/04/17 · arxiv updated 2015/06/19 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Grain-surface reactions play an essential role in interstellar chemistry, since dust grain catalyzes reactions at its surface allowing for the formation of molecules. We used a chemical model in which both gas-phase and grain-surface reactions occur and studied particularly the diffusion mechanisms on the surface of the grains. Surface reactions can occur via thermal hopping when species cross over a potential barrier or via quantum tunnelling when species cross through this barrier. We show that the thermal diffusion (hopping) can be much more efficient after a cosmic ray particle collides with a dust grain, heating it to a peak temperature of 70 K. We present here the results of numerical simulations after including the quantum tunnelling mechanism for species H, H2, and O and considering the effect of cosmic ray particle collision on the surface reactions. As a consequence, the gas-phase and grain-surface abundances are affected and we show that more complex molecules can be formed in molecular clouds.