A new coordinate transformation is developed which greatly simplifies the application of boundary conditions in studies of surface stability. The effect of radiation pressure on RayleighTaylor instabilities is examined for surfaces and slabs in the optically thin (fully compressible treatment) and optically thick (incompressible) limits. The ratio of the wave period to the recombination time has a striking effect on the stability of optically thick structures. In applying these results to QSO emission-line clouds, we find that (1) very optically thin clouds are unstable at their far side (leading edge) but the instability may not grow significantly during the cloud lifetime, (2) clouds which are just optically thick but fully ionized can be stabilized at both surfaces, and (3) optically thick clouds having significant amounts of neutral gas on their leading edges or clouds pushed from the rear by winds or other surface forces are strongly unstable and cannot persist. Subject headings: hydrodynamics - quasars
No takes yet. Share an insight, caveat, or question.
Mathews et al. (1977) studied this question.