FLAG HARE-AND-HOUNDS EXERCISE: ON THE EXTRACTION OF SECTORAL MODE SPLITTINGSFROM FULL-DISC, SUN-AS-A-STAR DATA

摘要

We report on results from the Fitting at Low-Angular degree Group (FLAG) Hare-and-Hounds exercise. Ten members of the group fitted an artificial 9.5-yr dataset that was constructed by the lead author to mimic full-disc Doppler velocity observations of the Sun. The sectoral mode splittings were the first parameter estimates chosen for scrutiny. The splittings of the different 'hounds' were found to show similar features as a function of frequency that are associated with realization noise in the data. However, there was noticeable disagreement between results at ι = 2 and 3. Evidence is presented that suggests this probably reflects the different way in which the fitters modelled the m-component height ratios in modes with more than two visible resonant peaks.