相关论文: Solar models and electron screening
In this paper, we construct background solar models that are stable against convection, by modifying the vertical pressure gradient of Model S (Christensen-Dalsgaard et al., 1996, Science, 272, 1286) relinquishing hydrostatic equilibrium.…
We review recent advances concerning helioseismology, solar models and solar neutrinos. Particularly we address the following points: i) helioseismic tests of recent SSMs; ii) predictions of the Beryllium neutrino flux based on…
We examine the constraints imposed by helioseismic data on the solar heavy element abundances. In prior work we argued that the measured depth of the surface convection zone R_CZ and the surface helium abundance Y_surf were good metallicity…
Heavy element and helium diffusion are both included for the first time in this series of papers on precise solar models, along with improvements in the input data for nuclear reaction rates, the solar luminosity, the solar age, heavy…
We present our results concerning a systematical analysis of helioseismic implications on solar structure and neutrino production. We find Y$_{ph}=0.238-0.259$, $R_b/R_\odot=0.708-0.714$ and $\rho_b=(0.185-0.199)$ gr/cm$^3$. In the interval…
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…
In connection with the recent suggestion by Tsytovich et al. that opacity in the solar core could be overestimated, we consider the following questions: i) What would a 10\% opacity reduction imply for the solar neutrino puzzle? ii) Is…
Helioseismic observations have revealed many properties of the Sun: the depth and the helium abundance of the convection zone, the sound-speed and the density profiles in the solar interior. Those constraints have been used to judge the…
The predictions of an improved standard solar model are compared with the observations of the four solar neutrino experiments. The improved model includes premain sequence evolution, element diffusion, partial ionization effects, and all…
We report on an ongoing investigation into a seismic calibration of solar models designed for estimating the main-sequence age and a measure of the chemical abundances of the Sun. Only modes of low degree are employed, so that with…
Context. Acoustic waves in the Sun are affected by the atmospheric layers, but this region is often ignored in forward models due to the increase in computational cost. Aims. The purpose of this work is to take into account the solar…
Frequencies of intermediate-degree f-modes of the Sun seem to indicate that the solar radius is smaller than what is normally used in constructing solar models. We investigate the possible consequences of an error in radius on results for…
We have computed new solar models using the same stellar evolution code as described in Charbonnel, Vauclair and Zahn (1992). This code, originating from Geneva, now includes the computation of element segregation for helium and 12 heavier…
Solar evolutionary models are thus far unable to reproduce spectroscopic, helioseismic, and neutrino constraints consistently, resulting in the so-called solar modeling problem. In parallel, planet formation models predict that the evolving…
An improved standard solar model has been used to calculate the fluxes of standard solar neutrinos. It includes premain sequence evolution, element diffusion, partial ionization effects, and all the possible nuclear reactions between the…
Localized differences between the real sun and standard solar models are shown to be small. The sound speeds of the real and the standard model suns typically differ by less than 0.3% in the solar core.
The recent downward revision of solar photospheric abundances of Oxygen and other heavy elements has resulted in serious discrepancies between solar models and solar structure as determined through helioseismology. In this work we…
Improvements induced by helioseismology show that microscopic diffusion cannot be neglected in solar models. Helium and metal diffusion is now generally introduced in the computations. They cannot however explain the observed lithium…
Context. The most recent determination of the solar chemical composition, using a time-dependent, 3D hydrodynamical model of the solar atmosphere, exhibits a significant decrease of C, N, O abundances compared to their previous values.…
We evaluate the effect of electrostatic screening by ions and electrons on low-Z thermonuclear reactions in the sun. We use a mean field formalism and calculate the electron density of the screening cloud using the appropriate density…