Cross-Correlation Technique in Individual Splitting Determination
Abstract
We review here the cross-correlation technique applied to the individual splitting measurement in Golf data. We perform the cross-correlation of the same multiplet taken from two different power spectra: in the ideal situation, the result is looking like a triplet of Lorentzian for l = 1 (5 for l = 2 and 7 for l = 3) with a constant separation given by the splitting (Lazrek et al. 1996). We use a continuous time serie of 18-months Golf data, whith no frequency shift due to the solar cycle (Fierry Fraillon et al. 1998), and we can then produce 6 differents realisations of the same multiplet corresponding to a 3-months spectral resolution. A sidereal value of the splitting is then deduced for each n,l modes using the average of the corresponding 15 cross-correlations. The results show the independence of the splitting as a function of the order n, and the agreement with a rigid solar core rotation.
- Publication:
-
Structure and Dynamics of the Interior of the Sun and Sun-like Stars
- Pub Date:
- 1998
- Bibcode:
- 1998ESASP.418..161F