A Nonlocal Calculation of Circumstellar OH Masers

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Session 81 -- Stellar Winds and Outflows
Display presentation, Friday, January 14, 9:30-6:45, Salons I/II Room (Crystal Gateway)

[81.06] A Nonlocal Calculation of Circumstellar OH Masers

A. J. Collison (UIUC), G. E. Nedoluha (NRL)

We present calculations for circumstellar OH masers which explicitly account for the nonlocal interaction throughout the masing region. Excitation temperatures and observed emission are calculated for all four ground state maser lines. All other transitions are treated using a modified Sobolev approximation. Calculations are performed within the context of a simplified dust/outflow model which provides the pumping conditions and their variation with radius. Total velocity relaxation is implicitly assumed in the calculations. We find general agreement with the qualitative results of earlier work (Collison \& Nedoluha, ApJ, 10 Feb 94 issue) and agree with the conclusions of Alcock \& Ross (1986, ApJ, 305, 837) who showed that observed profiles can not be produced by a smooth, spherically symmetric wind model of the outflow.

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