On the radiative damping of p-modes in solar magnetic flux concentrations

In a generalization of a work describing the propagation of compressive disturbances in a radiating fluid, we include the dynamical influence of a uniform magnetic field. The radiating fluid is treated to be gray, in LTE and assumed to obey the Eddington approximation. We apply these results to the interaction of solar p-modes with sunspots in the context of a simple model. For physical conditions representative of the solar envelope and for a variety of embedded magnetic structures, the temperature fluctuations associated with compressive waves are reduced inside the magnetic regions. Hence, radiative damping of these disturbances is suppressed to an extent that depends upon the nature of the mode (fast or slow magnetoacoustic) and the propagation direction relative to the uniform background field. This conclusion raises some interesting predictions concerning the observational signatures of compressive waves in the solar envelope