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 <ν<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 ω^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.

Revised version. 1.2 mHz features identified as artifacts of data analysis. Accepted for publication in ApJ

References in corpus (1)

• Ring diagram analysis of near-surface flows in the Sun

Cited by in corpus (6)

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• Constructing and Characterising Solar Structure Models for Computational Helioseismology
• Effect of asymmetry in peak profiles on solar oscillation frequencies
• Comparison of High-degree Solar Acoustic Frequencies and Asymmetry between Velocity and Intensity Data