Global low frequency acoustic modes after half a solar cycle aboard SOHO: An improved view of the nuclear core

Solar global oscillations have now been measured for more than 20 years. The study of these modes has contributed to improve, along time, the description of the solar core. We have now a proper access to this part of the Sun, with ground networks observing for more than 10 years and the three instruments aboard SOHO in a quasi continuous mode for now half a cycle. In this talk, we show the advantages of the global acoustic modes measured at low frequency. They are due to their longer lifetime and the reduced influence of the turbulent and variable surface effects. As a consequence, we have converged last year, after 30 years of unsucess, to a boron-8 emitted neutrino flux in perfect agreement with the better understood detection of these neutrinos on earth. The splitting at low frequency is also now properly determined but the extracted rotation information is still limited in the core. It contains nevertheless the first dynamical vision of this part of the radiative zone. We will focus on it up to the end of the SOHO mission, together with the gravity mode region and the possible internal signature of the magnetic field. Some limits are given on these observables. Further improvements of their detectability are under study and will be mentioned.