Grain Dynamics in Photodissociation Regions
Abstract
We discuss the forces on grains exposed to anisotropic radiation fields, including the usual ``radiation pressure'' force and also recoil forces due to photoemitted electrons, photodesorbed hydrogen atoms, and hydrogen molecules which form on the grain surface. We show that these forces can lead to grain dynamics in photodissociation regions which result in enhanced dust-to-gas ratios. Since the gas heating is probably dominated by photoelectric emission from dust, this might explain the unusually high gas temperatures inferred from ISO observations of molecular hydrogen in photodissociation regions.
Keywords
Cite
@article{arxiv.astro-ph/9812468,
title = {Grain Dynamics in Photodissociation Regions},
author = {Joseph C. Weingartner and Bruce T. Draine},
journal= {arXiv preprint arXiv:astro-ph/9812468},
year = {2007}
}
Comments
LaTeX (4 pages, 4 eps figures, uses iso98.sty and twocolumn.sty macros); to appear in "The Universe as Seen by ISO", Eds. P. Cox and M.F. Kessler, ESA Special Publications Series (SP-427)