Herschel Space Observatory - Theoretical Research Proposal #1004

The physics and chemistry of diffuse molecular clouds: theoretical studies motivated by Herschel

Principal Investigator: David Neufeld
           Institution: Johns Hopkins Univ

Co-Investigators: 
Mark Wolfire, University of Maryland
Michael Kaufman, San Jose State Univ

Dollars Approved: 200025

Abstract:
We propose to undertake a theoretical investigation of the physics and chemistry
within diffuse and translucent molecular clouds, motivated by the great
observational opportunities presented by Herschel.  Our study will focus on simple
hydride molecules and molecular ions that will be detectable with Herschel: these
include H2O, H3O+, OH+, HF, HCl, and HCl+.  These species promise to provide
critical clues about the chemical processes operating in molecular clouds, and will
address key questions related to the importance of high-temperature reactions in
so-called cold molecular clouds, the importance of gas-grain processes within the
interstellar medium, and the ionization level in molecular clouds.  We will make use
of – and extend – existing theoretical models for the chemistry of molecules
containing the elements carbon, oxygen, flourine and chlorine.