Doctor of Philosophy (PhD)
Physics and Astronomy
First Committee Member
Second Committee Member
Third Committee Member
Fourth Committee Member
Number of Pages
This dissertation develops a model for the response of the transition points in the density profiles from atomic (H0) to molecular (H2) hydrogen in a photodissociation region (PDR) due to a hard X-ray flux (HXR). A model for a steady-state PDR due to the photodissociation of H2 by the far-ultraviolet (FUV) Lyman-Werner radiation band is presented both analytically and computa- tionally. A steady state X-ray dissociation region (XDR) from an HXR in the 1 - 100 keV energy range is also developed both analytically and computationally. An analytic model is then developed by combining these two different steady state models. The inclusion of the hard X-rays gives rise to additional ionization in the PDR from secondary electrons which also leads to the generation of an internal FUV radiation field. Computational results for the density profiles and the response of the transition point of the PDR due to the HXR flux are given. A simple analytic formula based upon the separate PDR and XDR is then given which can provide an approximation to the transition point due to their combination.
Astrophysics and Astronomy
University of Nevada, Las Vegas
Colarch, Gregory Joseph, "The Response of Atomic-to-Molecular Hydrogen Transition Points in Photodissociation Regions Due to a Hard X-Ray Spectrum" (2023). UNLV Theses, Dissertations, Professional Papers, and Capstones. 4660.
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