EDP Sciences
Free access
Issue
A&A
Volume 391, Number 2, August IV 2002
Page(s) 725 - 739
Section The Sun
DOI http://dx.doi.org/10.1051/0004-6361:20020837


A&A 391, 725-739 (2002)
DOI: 10.1051/0004-6361:20020837

Seismic tests for solar models with tachocline mixing

A. S. Brun1, 2, H. M. Antia3, S. M. Chitre4 and J.-P. Zahn2

1  JILA, University of Colorado, Boulder, CO 80309-0440, USA
2  LUTH, Observatoire de Paris-Meudon, 92195 Meudon, France
    e-mail: jean.paul-zahn@obspm.fr
3  Tata Institute of Fundamental Research, Homi Bhabha road, Mumbai 400005, India
    e-mail: antia@tifr.res.in
4  Department of Physics, University of Mumbai, Mumbai 400098, India
    e-mail: kumarchitre@hotmail.com

(Received 24 February 2002 / Accepted 31 May 2002 )

Abstract
We have computed accurate 1-D solar models including both a macroscopic mixing process in the solar tachocline as well as up-to-date microscopic physical ingredients. Using sound speed and density profiles inferred through primary inversion of the solar oscillation frequencies coupled with the equation of thermal equilibrium, we have extracted the temperature and hydrogen abundance profiles. These inferred quantities place strong constraints on our theoretical models in terms of the extent and strength of our macroscopic mixing, on the photospheric heavy elements abundance, on the nuclear reaction rates such as  S11 and  S34 and on the efficiency of the microscopic diffusion. We find a good overall agreement between the seismic Sun and our models if we introduce a macroscopic mixing in the tachocline and allow for variation within their uncertainties of the main physical ingredients. From our study we deduce that the solar hydrogen abundance at the solar age is $X_{\rm inv}=0.732\pm 0.001$ and that based on the 9Be photospheric depletion, the maximum extent of mixing in the tachocline is 5% of the solar radius. The nuclear reaction rate for the fundamental pp reaction is found to be $S_{11}(0)=4.06\pm 0.07$ 10-25 MeV barns, i.e., 1.5% higher than the present theoretical determination. The predicted solar neutrino fluxes are discussed in the light of the new SNO/SuperKamiokande results.


Key words: Sun: abundances -- Sun: interior -- Sun: oscillations -- neutrinos

Offprint request: A. S. Brun, sabrun@solarz.colorado.edu




© ESO 2002