  The SoHO spacecraft made astrophysicists achieve a major breakthrough in the
knowledge of the Sun. In helioseismology, both GOLF and MDI experiments aboard
SoHO greatly improve the accuracy of seismic data. More specifically, the
detection of an enhanced number of low degree low order modes improves the
accuracy on the sound speed and density profiles in the solar core. After a
description of these profiles, we build solar seismic models. Different models
are considered and enable us to derive precise emitted neutrino fluxes. These
ones are validated by the seismic data and are in agreement with the recent
detected neutrinos, assuming 3 neutrino flavors. The seismic models are also
used to put limits on large scale magnetic fields in the solar interior. This
analysis puts some upper bounds of about 3x10^7 G in the radiative zone. Such a
field could slightly improve the emitted neutrino flux, which remains in
agreement with the Sudbury Neutrino Observatory result of 2001. From the models
we deduce gravity mode predictions, and the electron and neutron radial
densities that are useful to calculate the neutrino oscillations. We also begin
to discuss how the external magnetic field may influence such quantities.
