Bibcode
Chaplin, W. J.; Appourchaux, T.; Baudin, F.; Boumier, P.; Elsworth, Y.; Fletcher, S. T.; Fossat, E.; García, R. A.; Isaak, G. R.; Jiménez, A.; Jiménez-Reyes, S. J.; Lazrek, M.; Leibacher, J. W.; Lochard, J.; New, R.; Pallé, P.; Régulo, C.; Salabert, D.; Seghouani, N.; Toutain, T.; Wachter, R.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 369, Issue 2, pp. 985-996.
Advertised on:
6
2006
Citations
39
Refereed citations
28
Description
We report on results from the first solar Fitting at Low-Angular degree
Group (solar FLAG) hare-and-hounds exercise. The group is concerned with
the development of methods for extracting the parameters of low-l solar
p-mode data (`peak bagging'), collected by Sun-as-a-star observations.
Accurate and precise estimation of the fundamental parameters of the p
modes is a vital pre-requisite of all subsequent studies. Nine members
of the FLAG (the `hounds') fitted an artificial 3456-d data set. The
data set was made by the `hare' (WJC) to simulate full-disc Doppler
velocity observations of the Sun. The rotational frequency splittings of
the l = 1, 2 and 3 modes were the first parameter estimates chosen for
scrutiny. Significant differences were uncovered at l = 2 and 3 between
the fitted splittings of the hounds. Evidence is presented that suggests
this unwanted bias had its origins in several effects. The most
important came from the different way in which the hounds modelled the
visibility ratio of the different rotationally split components. Our
results suggest that accurate modelling of the ratios is vital to avoid
the introduction of significant bias in the estimated splittings. This
is of importance not only for studies of the Sun, but also of the solar
analogues that will be targets for asteroseismic campaigns.
Solar FLAG URL: http://bison.ph.bham.ac.uk/~wjc/Research/FLAG.html
E-mail: wjc [at] bison.ph.bham.ac.uk (wjc[at]bison[dot]ph[dot]bham[dot]ac[dot]uk) ‡
George Isaak passed away in 2005 June 5, prior to the completion of this
work. He is greatly missed by us all.