Physical Sciences and Mathematics Commons^™

Fluctuations In Astronomical Masers, Moshe Elitzur

Physics and Astronomy Faculty Publications

The radiation of astronomical masers fluctuates on the time scale 1/Gamma, where Gamma is the levels' loss rate. These intensity fluctuations reflect fluctuations of the level poulations around their mean, steady state values over the length scale λ_c = c/Γ. In saturated masers, the intensity fluctuations are dominated by passage through the unsaturated core. The effects of the saturated zones and of the seed radiation that the masers amplify can be neglected.

These fluctuations may have been detected in recent observations by Clegg and Cordes (1991) of Galactic H II/OH masers, providing a possible direct determination of the …

Radiative Transfer In Astronomical Masers. Iii. Filamentary Masers, Moshe Elitzur, Christopher F. Mckee, David J. Hollenbach

Physics and Astronomy Faculty Publications

This paper, the last in a series, presents the complete solution of a filamentary maser. The contribution of rays emanating from the filament sidewall is essential for the solution self-consistency during saturation. We develop an integral equation to calculate this contribution, devise an iteration scheme to solve it, and perform the first two iterations. The solution provides complete expressions for the distributions of intensity and flux across the source as functions of position and direction with regard to the axis. One consequence of radiation beaming, somewhat surprising at first, is that the filament appears smaller when viewed off-axis, at angles …