Bibcode
Gabriel, A. H.; Baudin, F.; Boumier, P.; García, R. A.; Turck-Chièze, S.; Appourchaux, T.; Bertello, L.; Berthomieu, G.; Charra, J.; Gough, D. O.; Pallé, P. L.; Provost, J.; Renaud, C.; Robillot, J.-M.; Roca Cortés, T.; Thiery, S.; Ulrich, R. K.
Bibliographical reference
Astronomy and Astrophysics, v.390, p.1119-1131 (2002)
Advertised on:
8
2002
Journal
Citations
74
Refereed citations
54
Description
With over 5 years of GOLF data having some 90% continuity, a new attempt
has been made to search for possible solar g modes. Statistical methods
are used, based on the minimum of assumptions regarding the solar
physics; namely that mode line-widths are small compared with the
inverse of the observing time, and that modes are sought in the
frequency interval 150 to 400 mu Hz. A number of simulations are carried
out in order to understand the expected behaviour of a system consisting
principally of a solar noise continuum overlaid with some weak sharp
resonances. The method adopted is based on the FFT analysis of a time
series with zero-padding by a factor of 5. One prominent resonance at
284.666 mu Hz coincides with a previous tentative assignment as one
member of an n=1, l=1, p-mode multiplet. Components of two multiplets,
previously tentatively identified as possible g-mode candidates from the
GOLF data in 1998, continue to be found, although their statistical
significance is shown to be insufficient, within the present assumption
regarding the nature of the signal. An upper limit to the amplitude of
any g mode present is calculated using two different statistical
approaches, according to either the assumed absence (H0 hypothesis) or
the assumed presence (H1 hypothesis) of a signal. The former yields a
slightly lower limit of around 6 mm/s.