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

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NLTE line formation calculations of FeI in the solar atmosphere are extended to include weak optical lines. Previously established atomic models are used to discriminate between different ways of treating collisional interaction processes.…

Astrophysics · Physics 2009-11-07 T. Gehren , A. J. Korn , J. Shi

The solar argon abundance cannot be directly derived by spectroscopic observations of the solar photosphere. The solar Ar abundance is evaluated from solar wind measurements, nucleosynthetic arguments, observations of B stars, HII regions,…

Astrophysics · Physics 2009-11-13 Katharina Lodders

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

We present nitrogen abundance measurements based on the low-ionisation [NII]6583 emission line for 588 galaxies between 1.5<z<7.0 from the JWST Advanced Deep Extragalactic Survey (JADES). We detect the temperature-sensitive [OIII]4363…

Accurate spectroscopic lithium abundances are essential in addressing a variety of open questions, such as the origin of a uniform lithium content in the atmospheres of metal-poor stars (Spite plateau) or the existence of a correlation…

Solar and Stellar Astrophysics · Physics 2020-07-01 A. Mott , M. Steffen , E. Caffau , K. G. Strassmeier

In this work, we investigated the nitrogen and oxygen abundances in a sample of galaxies with Low Ionization Nuclear Emission Regions (LINERs) in their nucleus. Optical spectroscopic data (3 600 - 10 000 {\AA}) of 40 LINERs from the Mapping…

The chemical compositions of stars encode the history of the universe and are thus fundamental for advancing our knowledge of astrophysics and cosmology. However, measurements of elemental abundances ratios, and our interpretations of them,…

Solar and Stellar Astrophysics · Physics 2024-01-02 Karin Lind , Anish Mayur Amarsi

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

The recent downward revision of the solar photospheric abundances now leads to severe inconsistencies between the theoretical predictions for the internal structure of the Sun and the results of helioseismology. There have been claims that…

Astrophysics · Physics 2009-11-13 T. Morel , K. Butler

Context: Recent works with improved model atmospheres, line formation, atomic and molecular data, and detailed treatment of blends, have resulted in a significant downward revision of the solar oxygen abundance. Aims: Considering the…

Astrophysics · Physics 2009-11-13 Jorge Melendez , Martin Asplund

We present a detailed spectroscopic analysis of nitrogen abundances in 91 solar-type stars, 66 with and 25 without known planetary mass companions. All comparison sample stars and 28 planet hosts were analysed by spectral synthesis of the…

Astrophysics · Physics 2016-08-16 A. Ecuvillon , G. Israelian , N. C. Santos , M. Mayor , R. J. García López , S. Randich

Non-local thermodynamical equilibrium (non-LTE) line formation for neutral and singly-ionized iron is considered through a range of spectral types when the effective temperature varies from 6500 K up to 8500 K, the gravity from log g = 4…

Solar and Stellar Astrophysics · Physics 2011-04-25 L. Mashonkina

The infrared (IR) range is extremely useful in the context of chemical abundance studies of the gas-phase interstellar medium (ISM) due to the large variety of ionic species traced in this regime, the negligible effects from dust…

Manganese (Mn) is a key Fe-group elements, commonly employed in stellar population and nucleosynthesis studies to explore the role of SN Ia. We have developed a new non-local thermodynamic equilibrium (NLTE) model of Mn, including new…

The lithium abundances in metal-poor halo stars are of importance for cosmology, galaxy evolution and stellar structure. In an attempt to study possible systematic errors in the derived Li abundances, the line formation of LiI lines has…

Astrophysics · Physics 2011-05-23 M. Asplund , M. Carlsson , A. Botnen

We report on non-LTE Ne abundances for a sample of B-type stellar members of the Orion Association. The abundances were derived by means of non-LTE fully metal-blanketed model atmospheres and extensive model atoms with updated atomic data.…

Astrophysics · Physics 2009-11-11 Katia Cunha , Ivan Hubeny , Thierry Lanz

In this review we discuss possible systematic errors inherent in classical 1D LTE abundance analyses of late-type stars for the light elements (here: H, He, Li, Be and B). The advent of realistic 3D hydrodynamical model atmospheres and the…

Solar and Stellar Astrophysics · Physics 2015-05-18 Martin Asplund , Karin Lind

The solar photospheric Fe abundance has been determined using realistic ab initio 3D, time-dependent, hydrodynamical model atmospheres. The study is based on the excellent agreement between the predicted and observed line profiles directly…

Astrophysics · Physics 2007-05-23 M. Asplund , AA. Nordlund , R. Trampedach , R. F. Stein

We investigate statistical equilibrium of neutral and singly-ionized strontium in late-type stellar atmospheres. Particular attention is given to the completeness of the model atom, which includes new energy levels, transition…

Solar and Stellar Astrophysics · Physics 2015-06-05 M. Bergemann , C. J. Hansen , M. Bautista , G. Ruchti

The chemical composition of the Sun is a fundamental yardstick in astronomy, relative to which essentially all cosmic objects are referenced. We reassess the solar abundances of all 83 long-lived elements, using highly realistic solar…

Solar and Stellar Astrophysics · Physics 2021-09-29 M. Asplund , A. M. Amarsi , N. Grevesse