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Related papers: The 3D non-LTE solar nitrogen abundance from atomi…

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Carbon abundances in late-type stars are important in a variety of astrophysical contexts. However C i lines, one of the main abundance diagnostics, are sensitive to departures from local thermodynamic equilibrium (LTE). We present a model…

Solar and Stellar Astrophysics · Physics 2019-04-24 A. M. Amarsi , P. S. Barklem , R. Collet , N. Grevesse , M. Asplund

A new model atom of nitrogen was developed using the energy levels of N I from laboratory measurements and also predicted in atomic structure calculations and the most up-to-date atomic data for computing radiative and collisional rates of…

Solar and Stellar Astrophysics · Physics 2024-06-18 L. I. Mashonkina , T. A. Ryabchikova

Carbon, nitrogen, and oxygen are the fourth, sixth, and third most abundant elements in the Sun. Their abundances remain hotly debated due to the so-called solar modelling problem that has persisted for almost $20$ years. We revisit this…

Solar and Stellar Astrophysics · Physics 2021-12-11 A. M. Amarsi , N. Grevesse , M. Asplund , R. Collet

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

Motivated by the controversy over the surface metallicity of the Sun, we present a re-analysis of the solar photospheric oxygen (O) abundance. New atomic models of O and Ni are used to perform Non-Local Thermodynamic Equilibrium (NLTE)…

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 solar photospheric oxygen abundance has been determined from [OI], OI, OH vibration-rotation and OH pure rotation lines by means of a realistic time-dependent, 3D, hydrodynamical model of the solar atmosphere. In the case of the OI…

Astrophysics · Physics 2009-07-09 M. Asplund , N. Grevesse , A. J. Sauval , C. Allende Prieto , D. Kiselman

Accurately known stellar lithium abundances may be used to shed light on a variety of astrophysical phenomena such as Big Bang nucleosynthesis, radial migration, ages of stars and stellar clusters, and planet engulfment events. We present a…

Solar and Stellar Astrophysics · Physics 2020-10-30 E. Wang , T. Nordlander , M. Asplund , A. M. Amarsi , K. Lind , Y. Zhou

CONTEXT: In recent years, the solar chemical abundances have been studied in considerable detail because of discrepant values of solar metallicity inferred from different indicators, i.e., on the one hand, the "sub-solar" photospheric…

Solar and Stellar Astrophysics · Physics 2015-05-13 E. Caffau , E. Maiorca , P. Bonifacio , R. Faraggiana , M. Steffen , H. -G. Ludwig , I. Kamp , M. Busso

The solar oxygen abundance has undergone a major downward revision in the last decade, the most noticeable one being the update including 3D hydrodynamical simulations to model the solar photosphere. Up to now, such an analysis has been…

The Oxygen abundance in the solar photosphere, and consequently the solar metallicity itself, is still a controversial issue with far-reaching implications in many areas of Astrophysics. This paper presents a new determination obtained by…

Solar and Stellar Astrophysics · Physics 2015-04-29 H. Socas-Navarro

The solar chemical abundances studied in considerable detail because of discrepant values of solar metallicity inferred from different indicators, where in the present work we have used 28 suitable atomic spectral solar nitrogen lines,…

Solar and Stellar Astrophysics · Physics 2018-09-17 Sameh I. S , M. M. Beheary , Abdelrazek M. K. Shaltout

The solar photospheric oxygen abundance is still widely debated. Adopting the solar chemical composition based on the "low" oxygen abundance, as determined with the use of three-dimensional (3D) hydrodynamical model atmospheres, results in…

Solar and Stellar Astrophysics · Physics 2016-08-08 M. Steffen , D. Prakapavičius , E. Caffau , H. -G. Ludwig , P. Bonifacio , R. Cayrel , A. Kučinskas , W. C. Livingston

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

Aims: we seek to provide additional tests of the line formation of theoretical 3D solar photosphere models. In particular, we set out to test the spatially-resolved line formation at several viewing angles, from the solar disk-centre to the…

Solar and Stellar Astrophysics · Physics 2015-05-14 Tiago M. D. Pereira , Dan Kiselman , Martin Asplund

We study the formation of O I and OH spectral lines in three-dimensional hydrodynamic models of the solar photosphere. The line source function of the O I 777 nm triplet is allowed to depart from local thermodynamic equilibrium (LTE),…

Astrophysics · Physics 2007-05-23 Dan Kiselman , Åke Nordlund

Neutral sodium is an important tracer of the Galactic chemical evolution, a powerful diagnostic of different stellar populations, and the subject of detailed studies of exoplanet atmospheres via transmission spectroscopy. This work aims to…

Solar and Stellar Astrophysics · Physics 2026-05-06 G. Canocchi , E. X. Wang , A. M. Amarsi , K. Lind , M. Racca

Silver is an important light neutron-capture element whose stellar abundances help constrain the origin of the weak r-process. The Sun is an important reference point for such studies; moreover, being a moderately volatile element in CI…

Solar and Stellar Astrophysics · Physics 2026-05-08 Sema Caliskan , Anish M. Amarsi , Per Jönsson , Nicolas Grevesse , Bijaya K. Sahoo

Solar oxygen abundance measurements based on the O I near-infrared triplet have been a much-debated subject for several decades since non-local thermodynamic equilibrium (NLTE) calculations with 3D radiation-hydrodynamics model atmospheres…

Solar and Stellar Astrophysics · Physics 2023-04-12 A. G. M. Pietrow , R. Hoppe , M. Bergemann , F. Calvo

Aluminium plays a key role in studies of the chemical enrichment of the Galaxy and of globular clusters. However, strong deviations from LTE (non-LTE) are known to significantly affect the inferred abundances in giant and metal-poor stars.…

Solar and Stellar Astrophysics · Physics 2017-11-28 Thomas Nordlander , Karin Lind
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