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Solar 5-min Oscillation Amplitude Anisotropy and Doppler Velocity Systematics

  • J. R. Kuhn
  • C. M. O’Neill
  • L. B. Gilliam
Conference paper
Part of the International Astronomical Union / Union Astronomique Internationale book series (IAUS, volume 123)

Abstract

Several measurements of 5-min velocity amplitudes have yielded confusing and conflicting information on the l and m dependence of the modal excitation (Kuhn and O’hanlon, 1983 - henceforth KO; Deubner, 1985; and Hill et al. 1985). We have obtained considerably more data than was described in KO using similar observing techniques. Additional analysis has illuminated a systematic effect related to the finite spatial resolution, and line asymmetry of the data that can lead to errors in inferred velocity amplitudes. Even though Doppler shifts are calculated from the Fraunhofer line center positions the effect can lead to 5-min oscillation amplitude errors at the 10 percent or greater level. Line wing observations should be more susceptible, and comparable resolution 2-dimensional data may be less sensitive to this systematic.

Keywords

Point Spread Function Line Profile Doppler Velocity Velocity Amplitude Line Wing 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© International Astronomical Union 1988

Authors and Affiliations

  • J. R. Kuhn
    • 1
  • C. M. O’Neill
    • 1
  • L. B. Gilliam
    • 2
  1. 1.Physics DepartmentPrinceton UniversityPrincetonUSA
  2. 2.National Solar ObservatoryNOAO SunspotUSA

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