Propagation of radiation in astrophysical media: Gravitational lenses and astrophysical masers

In Part I the time variability of the radiation emitted by astrophysical masers is studied by numerically solving the system of time dependent non-linear partial differential equations of radiative transfer through a masing gas. The calculations demonstrate for the first time how oscillations, with periods which are comparable to the light travel time through the maser, might develop as a result of radiative instabilities. In addition, we perform a linear stability analysis of the radiative transfer equations and the rate equations for the molecular populations of the masing transition. We use this stability analysis to determine the conditions and parameters for which an astrophysical maser would become unstable. Our results are in agreement with recent observations of astrophysical masers in which fluctuations are found on time scales as short as one thousand seconds.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Scappaticci, Gerardo Angelo

Contributors dc:contributor

• Watson, W.D.

• Physics, Astronomy and Astrophysics

Statement dc:rights

• Copyright 1992 Scappaticci, Gerardo Angelo

Language dc:language

eng

Identifier

AAI9305679
(UMI)AAI9305679

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/21822