Astron. Astrophys. 323, 231-234 (1997)

1. Introduction

The fine structure, or m dependence, in the spectrum of solar oscillations is customarily described by the a -coefficients of Duvall, Harvey and Pomerantz (1986) as,

where is the cyclic frequency of an individual -mode, , P is a Legendre polynomial, and N is the order of the Legendre expansion provided by the observers. The are the radial order, angular degree and azimuthal order of the oscillation, respectively.

We consider the symmetry of the fine structure about the centroid () frequency. The symmetric part (the odd-a 's) arises from the linear effect of the Sun's rotation. The antisymmetric part (the even-a 's), which is linked to the latitudinal variation of the solar activity, is the subject of this paper.

© European Southern Observatory (ESO) 1997

Online publication: June 5, 1998

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