SOLAR P-MODE FREQUENCIES FROM THE IRIS NETWORK

The Iris network for helioseismology has operated since 1989. We prese nt tables of solar p-mode frequencies for observations taken during th e four summer seasons from 1989 to 1992. This analysis uses the techni que of maximum likelihood fitting and a chi(2)(2) model for the probab ility density function of the spectrum. The simultaneous fitting of od d and even pairs of peaks strengthens the identification of the l = 3 eigenmodes and improves the error bars on the 0 - 2 group. The frequen cies are in good agreement with other observational results and with t heoretical values for the D-0 and the Delta nu parameters of the asymp totic approximation. A decrease of 0.25 +/- 0.12 mu Hz is seen between the 1989 and the 1992 data sets. The change is associated with the de crease of solar activity and is comparable with results of previous st udies.