On model predictions of the power spectral density of radial solar p modes |
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| Authors: | W J Chaplin G Houdek Y Elsworth D O Gough G R Isaak R New |
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| Institution: | School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT;Institute of Astronomy, University of Cambridge, Cambridge CB3 0HA;Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge CB3 0WA;South African Astronomical Observatory, PO Box 9, Observatory 7935, South Africa;School of Science &Mathematics, Sheffield Hallam University, Sheffield S1 1WB |
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| Abstract: | We investigate the frequency dependence of the power spectral density of low-degree solar p modes by comparing measurements with the results of a stochastic-excitation model. In the past it was common practice to use the total power in such investigations. Using the maximum of the power spectral density instead provides a direct comparison with the measured mode heights in the observed power spectrum. This method permits a more careful calibration of the adjustable parameters in the excitation model, a model which we present here, for the first time, in a format that precisely and unambiguously relates the amplitudes of the modes of oscillation to the Reynolds stress in the equilibrium model. We find that errors in the theory of the linear mode damping rates, particularly at low frequency, have a dramatic impact on the predictions of the mode heights in the spectral density, whereas parameter changes in the stochastic excitation model, within a plausible domain of parameter space, have a comparatively small effect. |
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| Keywords: | convection Sun: helioseismology |
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