English

Enhanced production of HD and D_2 molecules on small dust grains in diffuse clouds

Astrophysics 2009-11-10 v1

Abstract

Motivated by recent observations of deuterated molecules in the interstellar medium, we examine the production of HD and D2_2 molecules on dust grain surfaces. A mechanism for the enhanced production of these deuterated molecules is studied. This mechanism applies on grain surfaces on which D atoms stick more strongly than H atoms, under conditions of low flux and within a suitable range of temperatures. It is shown that under these conditions the production rates of HD and D2_2 are greatly enhanced (vs. the H2_2 production rate) compared with the expected rates based on the adsorption of gas-phase atomic abundances of D and H. The enhancement in the formation rate of HD is comparable with the enhancement due to gas-phase ion-molecule reactions in diffuse clouds.

Keywords

Cite

@article{arxiv.astro-ph/0311524,
  title  = {Enhanced production of HD and D_2 molecules on small dust grains in diffuse clouds},
  author = {Azi Lipshtat and Ofer Biham and Eric Herbst},
  journal= {arXiv preprint arXiv:astro-ph/0311524},
  year   = {2009}
}

Comments

This is a preprint of an article accepted for publication in Monthly Notices of The Royal Astromnomical Society