High‐Frequency and High‐Wavenumber Solar Oscillations

Abstract
We determine the frequencies of solar oscillations covering a wide range of degree (100< l <4000) and frequency (1.5 < u<10 mHz) using the ring diagram technique applied to power spectra obtained from MDI (Michelson Doppler Imager) data. The f-mode ridge extends up to degree of approximately 3000, where the line width becomes very large, implying a damping time which is comparable to the time period. The frequencies of high degree f-modes are significantly different from those given by the simple dispersion relation omega^2=gk. The f-mode peaks in power spectra are distinctly asymmetric and use of asymmetric profile increases the fitted frequency bringing them closer to the frequencies computed for a solar model.Comment: Revised version. 1.2 mHz features identified as artifacts of data analysis. Accepted for publication in Ap

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