Intermediate degree solar oscillations

Spectra of solar intensity oscillations in the degree range ℓ = 20–98 were obtained with a 92% duty cycle over a 50 hour period from the geographic South Pole. After correction for solar rotation, the spectra have been averaged over azimuthal order m and fit with Lorentzian functions to provide valu...

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Bibliographic Details
Published in:Symposium - International Astronomical Union
Main Authors: Duvall, T. L., Harvey, J. W., Pomerantz, M. A.
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 1988
Subjects:
Online Access:http://dx.doi.org/10.1017/s0074180900157687
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0074180900157687
Description
Summary:Spectra of solar intensity oscillations in the degree range ℓ = 20–98 were obtained with a 92% duty cycle over a 50 hour period from the geographic South Pole. After correction for solar rotation, the spectra have been averaged over azimuthal order m and fit with Lorentzian functions to provide values of background noise, amplitude, frequency and line width for 636 oscillation modes. The background noise is nearly independent of frequency in the range containing strong p-modes. The amplitude envelope shows little dependence on ℓ value and a frequency dependence similar to that of Doppler oscillations but shifted to higher frequency. Line widths increase at higher frequency and at higher ℓ values.