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Related papers: Solar oxygen abundance

200 papers

The purpose of this work is to better understand the confidence limits of the photospheric solar oxygen abundance derived from three-dimensional models using the forbidden [OI] line at 6300 \AA , including correlations with other parameters…

Solar and Stellar Astrophysics · Physics 2017-03-29 M. Cubas Armas , A. Asensio Ramos , H. Socas-Navarro

Accurate determination of photospheric solar abundances requires detailed modeling of the solar granulation and accounting for departures from local thermodynamical equilibrium (LTE). We argue that the forbidden C I line at 8727 A is…

Astrophysics · Physics 2009-11-07 Carlos Allende Prieto , David L. Lambert , Martin Asplund

We present the non-local thermodynamic equilibrium (non-LTE) calculations for O I with the updated model atom that includes quantum-mechanical rate coefficients for O I + H I inelastic collisions from the recent study of Barklem (2018). The…

Solar and Stellar Astrophysics · Physics 2018-08-23 Tatyana Sitnova , Lyudmila Mashonkina

An extremely high-resolution (> 10^5) high-S/N (> 10^3) solar spectrum has been used to measure 15 very weak first overtone (Delta v = 2) infrared OH lines, resulting in a low solar abundance of A(O) ~ 8.6 when MARCS, 3D, and spatially and…

Astrophysics · Physics 2009-11-10 Jorge Melendez

We study the solar photospheric abundance of singly ionized neodymium (Nd II) using high resolution spectroscopic data obtained by Fourier transform spectrograph (FTS). Based on the Local Thermodynamical Equilibrium (LTE) assumption, a new…

Solar and Stellar Astrophysics · Physics 2017-12-20 A. G. A. Abdelkawy , Abdelrazek M. K. Shaltout , M. M. Beheary , A. Bakry

We performed non-LTE calculations for O I with the plane-parallel model atmospheres for a set of stellar parameters corresponding to A-K type stars. The model atom of Przybilla et al. (2000) was updated using the best theoretical and…

Solar and Stellar Astrophysics · Physics 2013-02-06 T. M. Sitnova , L. I. Mashonkina , T. A. Ryabchikova

We present a new determination of the solar nitrogen abundance making use of 3D hydrodynamical modelling of the solar photosphere, which is more physically motivated than traditional static 1D models. We selected suitable atomic spectral…

Solar and Stellar Astrophysics · Physics 2010-11-22 E. Maiorca , E. Caffau , P. Bonifacio , M. Busso , R. Faraggiana , M. Steffen , H. -G. Ludwig , I. Kamp

A series of recent studies has placed the best estimates of the photospheric abundances of carbon and oxygen at log epsilon = 8.39 and 8.66, respectively. These values are ~ 40 % lower than earlier estimates. A coalition of corrections due…

Astrophysics · Physics 2007-05-23 Carlos Allende Prieto

The present-day abundance of beryllium in the solar atmosphere provides clues about mixing mechanisms within stellar interiors. However, abundance determinations based on the Be II 313.107 nm line are prone to systematic errors due to…

Solar and Stellar Astrophysics · Physics 2024-09-09 A. M. Amarsi , D. Ogneva , G. Buldgen , N. Grevesse , Y. Zhou , P. S. Barklem

We present three-dimensional (3D) non-local thermodynamic equilibrium (non-LTE) radiative transfer calculations for silicon in the solar photosphere, using an extensive model atom that includes recent, realistic neutral hydrogen collisional…

Solar and Stellar Astrophysics · Physics 2016-09-28 A. M. Amarsi , M. Asplund

The statistical equilibrium of neutral and ionised silicon in the solar photosphere is investigated. Line formation is discussed and the solar silicon abundance determined. High-resolution solar spectra were used to determine solar $\log…

Astrophysics · Physics 2009-11-13 J. R. Shi , T. Gehren , K. Butler , L. I. Mashonkina , G. Zhao

In this work we present new data that sets strong constraints on the solar oxygen abundance. Our approach, based on the analysis of spectro-polarimetric observations, is almost model-independent and therefore extremely robust. The asymmetry…

Astrophysics · Physics 2009-11-13 R. Centeno , H. Socas-Navarro

We present results from a series of observational tests to 3D and 1D solar models. In particular, emphasis is given to the line formation of atomic oxygen lines, used to derive the much debated solar oxygen photospheric abundance. Using…

Solar and Stellar Astrophysics · Physics 2009-09-24 Tiago M. D. Pereira , Martin Asplund , Dan Kiselman

Our ability to model the shapes and strengths of iron lines in the solar spectrum is a critical test of the accuracy of the solar iron abundance, which sets the absolute zero-point of all stellar metallicities. We use an extensive 463-level…

Solar and Stellar Astrophysics · Physics 2017-05-31 K. Lind , A. M. Amarsi , M. Asplund , P. S. Barklem , M. Bautista , M. Bergemann , R. Collet , D. Kiselman , J. Leenaarts , T. M. D. Pereira

Using realistic hydrodynamical simulations of the solar surface convection as 3D, time-dependent, inhomogeneous model atmospheres, the solar photospheric Si abundance has been determined to be log Si = 7.51 +- 0.04. This constitutes a…

Astrophysics · Physics 2008-11-26 M. Asplund

The OI 777 nm lines are among the most commonly used diagnostics for the oxygen abundances in the atmospheres of FGK-type stars. However, they form in conditions that are far from local thermodynamic equilibrium (LTE). We explore the…

Solar and Stellar Astrophysics · Physics 2015-12-09 A. M. Amarsi , M. Asplund , R. Collet , J. Leenaarts

We investigate the formation of neutral and singly ionized scandium lines in the solar photospheres. The research is aimed derive solar $\log gf\epsilon_{\odot}$(Sc) values for scandium lines, which will later be used in differential…

Astrophysics · Physics 2008-02-20 H. W. Zhang , T. Gehren , G. Zhao

Oxygen is a powerful tracer element of Galactic chemical evolution. Unfortunately, only a few oxygen lines are available in the ultraviolet-infrared stellar spectra for the reliable determination of its abundance. Moreover, oxygen…

Solar and Stellar Astrophysics · Physics 2014-09-11 A. Kucinskas , V. Dobrovolskas , P. Bonifacio , E. Caffau , H. -G. Ludwig , M. Steffen , M. Spite

The possibility of unaccounted for opacity sources in the UV for late-type stars has often been invoked to explain discrepancies between predicted and observed flux distributions and spectral line strengths. Such missing UV-opacity could…

Astrophysics · Physics 2009-11-10 M. Asplund

The solar abundances have undergone a major downward revision in the last decade, reputedly as a result of employing 3D hydrodynamical simulations to model the inhomogeneous structure of the solar photosphere. The very low oxygen abundance…

Solar and Stellar Astrophysics · Physics 2009-10-27 E. Caffau , H. -G. Ludwig , M. Steffen