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Restriction data tranferred 2014-07-01T11:13:46-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis Thesis U of I Only 3471910 http://hdl.handle.net/2142/25205 en 1990 Gerald Ernst Nedoluha polarized radiation astrophysical masers Watson, W.D. Nedoluha, Gerald Ernst 2011-06-01T15:59:26Z 2011-06-01T15:59:26Z 10000-01-01 1990 "Polarized emission from astrophysical masers can provide important information about physical conditions in both star forming and circumstellar environments. Calculations are performed which give the spectra of the emergent maser radiation for different magnetic fields, radiative intensities, decay rates, and pumping rates thought to be appropriate in astrophysical masing regions. Results are obtained which for the first time make it possible to study the linear polarization of radiatively saturated masers when the stimulated emission rate and the Zeeman frequency are comparable, a regime which is of importance for nonparamagnetic masing molecules (i.e. H20, SiO, CH30H, H2CO) in astrophysics. The change in both the amount of linear polarization and its position angle as a function of the stimulated emission rate is followed through this regime. A striking feature of maser emission from OH molecules is the tendency for one of the circular polarizations to dominate the emission spectrum. The two mechanisms which may explain these observations both involve a masing gas in a velocity gradient These mechanisms are studied by calculating the emergent spectra of the radiation without making the ""large velocity gradient"" approximation which has always been made in previous calculations of masing in a velocity gradient. Eliminating this approximation leads to previously unsuspected narrow line profiles even in regions where large velocity gradients are present, as well as to polarized spectra that resemble those of the observations." Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-06-01T15:59:26Z No. of bitstreams: 1 1990_nedoluha.pdf: 4604747 bytes, checksum: dfd9d3bb1a96217062dd5ecd62e8feda (MD5) Made available in DSpace on 2011-06-01T15:59:26Z (GMT). No. of bitstreams: 1 1990_nedoluha.pdf: 4604747 bytes, checksum: dfd9d3bb1a96217062dd5ecd62e8feda (MD5) Previous issue date: 1990 Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-06-01T15:59:26Z Item is restricted indefinitely. star formation circumstellar environments The transfer of polarized radiation in astrophysical masers in the presence of magnetic fields Dissertation / Thesis text Physics Physics University of Illinois at Urbana-Champaign Dissertation Ph.D.