Award Date

1-1-2004

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Physics

First Committee Member

Stephen Lepp

Number of Pages

30

Abstract

This study concerns the cooling that occurs in molecular clouds. The contribution to the cooling in these clouds by collisions between hydrogen molecules and helium atoms was investigated. The semi-classical method was used to calculate the rate coefficients for all He-induced H2 ro-vibrational transitions, and these were compared with previous quantum mechanical calculations. The steady state ro-vibrational level populations were found and used to compute the cooling function over a range of temperatures and densities. The time required to reach steady state is discussed, and a comparison is made of the results to corresponding values in thermodynamic equilibrium. The cooling function is compared to a previous quantum mechanical calculation. The suitability of the semi-classical method is discussed.

Keywords

Atoms; Collisions; Cooling; Helium; Hydrogen; Molecules

Controlled Subject

Astronomy

File Format

pdf

File Size

634.88 KB

Degree Grantor

University of Nevada, Las Vegas

Language

English

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