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Related papers: NLTE study of scandium in the Sun

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Following our solar work, we perform NLTE calculations of the Mn abundance for fourteen stars with [Fe/H] from 0 to -2.5, mainly to show how NLTE affects Mn abundances in cool stars of different metallicities.The spectrum synthesis and Mn…

Astrophysics · Physics 2009-11-13 Maria Bergemann , Thomas Gehren

Strontium has proven itself to be one of the most important neutron-capture elements in the study of metal-poor stars. Thanks to the strong absorption lines of Sr, they can be detected even in the most metal-poor stars and also in…

The possibility of significant systematic errors due to the use of 1D homogeneous atmospheres in lithium-abundance determinations of cool stars motivates a study of non-local-thermodynamic-equilibrium (NLTE) effects on Li I line formation…

Astrophysics · Physics 2009-10-30 Dan Kiselman

In this work, we present a photospheric solar silicon abundance derived using CO5BOLD model atmospheres and the LINFOR3D spectral synthesis code. Previous works have differed in their choice of a spectral line sample and model atmosphere as…

Solar and Stellar Astrophysics · Physics 2022-12-16 S. A. Deshmukh , H. -G. Ludwig , A. Kučinskas , M. Steffen , P. S. Barklem , E. Caffau , V. Dobrovolskas , P. Bonifacio

We investigate departures from local thermodynamic equilibrium (NLTE) in the line formation of neutral and singly ionised iron lines and their impact on spectroscopic stellar parameters. The calculations are performed for an extensive grid…

Solar and Stellar Astrophysics · Physics 2015-06-05 Karin Lind , Maria Bergemann , Martin Asplund

The non-local thermodynamic equilibrium (NLTE) line formation of neutral boron in the atmospheres of cool stars are investigated. Our results confirm that NLTE effects for the B I resonance lines, which are due to a combination of…

Solar and Stellar Astrophysics · Physics 2010-04-07 Kefeng Tan , Jianrong Shi , Gang Zhao

The lifetimes of 17 even-parity levels (3d5s, 3d4d, 3d6s, and 4p$^2$) in the region 57743-77837 cm$^{-1}$ of singly ionised scandium (\ion{Sc}{ii}) were measured by two-step time-resolved laser induced fluorescence spectroscopy. Oscillator…

Solar and Stellar Astrophysics · Physics 2017-08-23 A. Pehlivan Rhodin , M. T. Belmonte , L. Engstrom , H. Lundberg , H. Nilsson , H. Hartman , J. C. Pickering , C. Clear , P. Quinet , V. Fivet , P. Palmeri

The non-local thermodynaic equilibrium (non-LTE) line formation for the two ions of zirconium is considered through a range of spectral types when the Zr abundance varies from the solar value down to [Zr/H] = -3. The model atom was built…

Solar and Stellar Astrophysics · Physics 2015-05-27 A. Velichko , L. Mashonkina , H. Nilsson

We constructed a comprehensive model atom for C\ione\ -- C\ii\ using the most up-to-date atomic data available and evaluated the non-local thermodynamic equilibrium (NLTE) line formation for C\ione\ and C\ii\ in classical 1D models…

Solar and Stellar Astrophysics · Physics 2016-08-17 S. A. Alexeeva , T. A. Ryabchikova , L. I. Mashonkina

The generally adopted value for the solar abundance of indium is over six times higher than the meteoritic value. We address this discrepancy through numerical synthesis of the 451.13 nm line on which all indium abundance studies are based,…

Astrophysics · Physics 2009-11-13 N. Vitas , I. Vince , M. Lugaro , O. Andriyenko , M. Gosic , R. J. Rutten

Context: The stable element hafnium (Hf) and the radioactive element thorium (Th) were recently suggested as a suitable pair for radioactive dating of stars. The applicability of this elemental pair needs to be established for stellar…

Astrophysics · Physics 2009-11-13 Elisabetta Caffau , L. Sbordone , H. -G. Ludwig , P. Bonifacio , M. Steffen , N. T. Behara

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

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 constructed a comprehensive model atom for NeI -- NeII using the most up-to-date atomic data available and evaluated the non-local thermodynamic equilibrium (NLTE) line formation for NeI and NeII in classical 1D models representing the…

Solar and Stellar Astrophysics · Physics 2020-06-24 Sofya Alexeeva , Tianxiang Chen , Tatyana Ryabchikova , Weibin Shi , Kozo Sadakane , Masayoshi Nishimura , Gang Zhao

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

Solar photospheric abundances and CI-chondrite compositions are reviewed and updated to obtain representative solar system abundances of the elements and their isotopes. The new photospheric abundances obtained here lead to higher solar…

Solar and Stellar Astrophysics · Physics 2025-02-18 Katharina Lodders , Maria Bergemann , Herbert Palme

The non-local thermodynamical equilibrium (NLTE) line formation of Y I and Y II is considered in 1D LTE model atmospheres of F-G-K-type stars. The model atom was constructed with the most up-to-date atomic data, including quantum cross…

Solar and Stellar Astrophysics · Physics 2023-09-06 Sofya Alexeeva , Yu Wang , Gang Zhao , Feng Wang , Yong Wu , Jianguo Wang , Hongliang Yan , Jianrong Shi

Aiming at testing the validity of our magnesium atomic model and investigating the effects of non-local thermodynamical equilibrium (NLTE) on the formation of the H-band neutral magnesium lines, we derive the differential Mg abundances from…

Solar and Stellar Astrophysics · Physics 2017-01-25 Junbo Zhang , Jianrong Shi , Kaike Pan , Carlos Allende Prieto , Chao Liu

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

Extensive statistical-equilibrium calculations on neutral sulfur and zinc were carried out, in order to investigate how the non-LTE effect plays a role in the determination of S and Zn abundances in F, G, and K stars. Having checked on the…