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Related papers: Chemical Abundances from the Continuum

200 papers

We present a measurement of the abundance of Fe relative to H in the solar corona using a technique which differs from previous spectroscopic and solar wind measurements. Our method combines EUV line data from the CDS spectrometer on SOHO…

Astrophysics · Physics 2016-08-30 S. M. White , R. J. Thomas , J. W. Brosius , M. R. Kundu

We show that standard solar models are in good agreement with the helioseismologically determined sound speed and density as a function of solar radius, the depth of the convective zone, and the surface helium abundance, as long as those…

Astrophysics · Physics 2011-09-29 John N. Bahcall , Sarbani Basu , Marc Pinsonneault , Aldo M. Serenelli

We construct solar models with the newly calculated radiative opacities from the Opacity Project (OP) and recently determined (lower) heavy element abundances. We compare results from the new models with predictions of a series of models…

Astrophysics · Physics 2009-11-10 John N. Bahcall , Aldo M. Serenelli , Sarbani Basu

We redetermine the abundances of all iron group nuclei in the Sun, based on neutral and singly-ionised lines of Sc, Ti, V, Mn, Fe, Co and Ni in the solar spectrum. We employ a realistic 3D hydrodynamic model solar atmosphere, corrections…

Solar and Stellar Astrophysics · Physics 2014-12-17 Pat Scott , Martin Asplund , Nicolas Grevesse , Maria Bergemann , A. Jacques Sauval

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…

Astrophysics · Physics 2009-11-11 H. M. Antia , Sarbani Basu

A broad array of interstellar absorption features that appear in the ultraviolet spectra of bright sources allows us to measure the abundances and ionization states of many important heavy elements that exist as free atoms in the…

Astrophysics · Physics 2007-05-23 Edward B. Jenkins

Recent downward revision of solar heavy-element abundances using three-dimensional atmospheric model has introduced serious discrepancies between standard solar models and helioseismic inferences about solar structure. In this paper, we…

Astrophysics · Physics 2009-11-13 Chia-Hsien Lin , H. M. Antia , Sarbani Basu

We generate new standard solar models using newly analyzed nuclear fusion cross sections and present results for helioseismic quantities and solar neutrino fluxes. We discuss the status of the solar abundance problem and investigate whether…

Solar and Stellar Astrophysics · Physics 2015-05-27 Aldo M. Serenelli , Wick C. Haxton , Carlos Pena-Garay

We present a compiled catalogue of effective temperatures, surface gravities, iron and magnesium abundances, distances, velocity components, and orbital elements for stars in the solar neighborhood. The atmospheric parameters and iron…

Astrophysics · Physics 2009-11-10 T. V. Borkova , V. A. Marsakov

To study the structure of spatially unresolved features of the solar photosphere, we calculated the Stokes profiles of seven photospheric iron lines using two-dimensional nonstationary MHD models of solar granulation for various amounts of…

Solar and Stellar Astrophysics · Physics 2012-11-13 I. N. Atroshchenko , V. A. Sheminova

Standard solar models (SSM) are facing nowadays a new puzzle: the solar composition problem. New determinations of solar metal abundances lead SSM calculations to conflict with helioseismological measurements, showing discrepancies that…

Astrophysics · Physics 2008-11-18 Carlos Pena-Garay , Aldo Serenelli

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…

High Energy Physics - Phenomenology · Physics 2008-11-26 John N. Bahcall , M. H. Pinsonneault

Recently, new solar model atmospheres have been developed to replace classical 1D LTE hydrostatic models and used to for example derive the solar chemical composition. We aim to test various models against key observational constraints. In…

Solar and Stellar Astrophysics · Physics 2015-06-15 Tiago M. D. Pereira , Martin Asplund , Remo Collet , Irina Thaler , Regner Trampedach , Jorrit Leenaarts

Using archival Far Ultraviolet Spectroscopic Explorer (FUSE) and Hubble Space Telescope (HST) data, we have assembled a survey of eight sightlines through high-velocity cloud Complex C. Abundances of the observed ion species vary…

Astrophysics · Physics 2009-11-07 J. A. Collins , J. M. Shull , M. L. Giroux

We perform a quantitative analysis of the solar composition problem by using a statistical approach that allows us to combine the information provided by helioseimic and solar neutrino data in an effective way. We include in our analysis…

Solar and Stellar Astrophysics · Physics 2015-06-18 F. L. Villante , A. M. Serenelli , F. Delahaye , M. H. Pinsonneault

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…

Solar and Stellar Astrophysics · Physics 2010-05-05 F. Delahaye , M. H. Pinsonneault , L. Pinsonneault , C. J. Zeippen

Changes in the solar surface area covered by small-scale magnetic elements are thought to cause long-term changes in the solar spectral irradiance, which are important for determining the impact on Earth's climate. To study the effect of…

Solar and Stellar Astrophysics · Physics 2015-05-20 N. Afram , Y. C. Unruh , S. K. Solanki , M. Schuessler , A. Lagg , A. Voegler

The Sun is believed to have been the recipient of a substantial amount of metal-rich material over the course of its evolution, particularly in the early stages of the Solar System. With a long diffusion timescale, the majority of this…

Astrophysics · Physics 2009-11-07 R. A. Winnick , Pierre Demarque , Sarbani Basu , D. B. Guenther

We have evolved 10,000 solar models using 21 input parameters that are randomly drawn for each model from separate probability distributions for every parameter. We use the results of these models to determine the theoretical uncertainties…

Astrophysics · Physics 2008-11-26 John N. Bahcall , Aldo M. Serenelli , Sarbani Basu

Zirconium (Zr), together with strontium and yttrium, is an important element in the understanding of the Galactic nucleosynthesis. In fact, the triad Sr-Y-Zr constitutes the first peak of s-process elements. Despite its general relevance…

Solar and Stellar Astrophysics · Physics 2015-05-20 Elisabetta Caffau , Rosanna Faraggiana , Hans-Günter Ludwig , Piercarlo Bonifacio , Matthias Steffen