Bibcode
García, R. A.; Turck-Chièze, S.; Jiménez-Reyes, S. J.; Ballot, J.; Pallé, P. L.; Eff-Darwich, A.; Mathur, S.; Provost, J.
Bibliographical reference
Proceedings of SOHO 18/GONG 2006/HELAS I, Beyond the spherical Sun (ESA SP-624). 7-11 August 2006, Sheffield, UK. Editor: Karen Fletcher. Scientific Editor: Michael Thompson, Published on CDROM, p.23.1
Advertised on:
10
2006
Citations
2
Refereed citations
1
Description
In the present work we show robust indications of the existence of g
modes in the Sun using 10 years of GOLF data. The present analysis is
based on the exploitation of the collective properties of the predicted
low-frequency (25 to 140 microHz) g modes: their asymptotic nature,
which implies a quasi equidistant separation of their periods for a
given angular degree (l). The Power Spectrum (PS) of the Power Spectrum
Density (PSD), reveals a significant structure indicating the presence
of features (peaks) in the PSD with near equidistant periods
corresponding to l=1 modes in the range n=-4 to n=-26. The study of its
statistical significance of this feature was fully undertaken and
complemented with Monte Carlo simulations. This structure has a
confidence level better than 99.86% not to be due to pure noise.
Furthermore, a detailed study of this structure suggests that the
gravity modes have a much more complex structure than the one initially
expected (line-widths, magnetic splittings...). Compared to the latest
solar models, the obtained results tend to favor a solar core rotating
significantly faster than the rest of the radiative zone. In the
framework of the Phoebus group, we have also applied the same
methodology to other helioseismology instruments on board SoHO and
ground based networks.