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相关论文: Statistical equilibrium of silicon in the solar at…

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Aims. The statistical equilibrium of neutral and ionized silicon in the atmospheres of metal-poor stars is discussed. Non-local thermodynamic equilibrium effects are investigated and the silicon abundances in metal-poor stars determined.…

太阳与恒星天体物理 · 物理学 2015-05-13 J. R. Shi , T. Gehren , L. Mashonkina , G. Zhao

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…

天体物理学 · 物理学 2008-02-20 H. W. Zhang , T. Gehren , G. Zhao

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…

太阳与恒星天体物理 · 物理学 2016-09-28 A. M. Amarsi , M. Asplund

Nitrogen is an important element in various fields of stellar and Galactic astronomy, and the solar nitrogen abundance is crucial as a yardstick for comparing different objects in the cosmos. In order to obtain a precise and accurate value…

太阳与恒星天体物理 · 物理学 2020-04-29 A. M. Amarsi , N. Grevesse , J. Grumer , M. Asplund , P. S. Barklem , R. Collet

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)…

The properties of non-statistical equilibrium ionization of silicon and oxygen ions are analyzed in this work. We focus on four solar targets (quiet sun, coronal hole, plage, quiescent active region, AR, and flaring AR) as observed with the…

太阳与恒星天体物理 · 物理学 2016-01-27 Juan Martinez-Sykora , Bart De Pontieu , Viggo H. Hansteen , Boris V. Gudiksen

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…

太阳与恒星天体物理 · 物理学 2022-12-16 S. A. Deshmukh , H. -G. Ludwig , A. Kučinskas , M. Steffen , P. S. Barklem , E. Caffau , V. Dobrovolskas , P. Bonifacio

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.…

天体物理学 · 物理学 2009-11-07 T. Gehren , A. J. Korn , J. Shi

In this paper we investigate statistical equilibrium of Ti in the atmospheres of late-type stars. The Ti I/Ti II level populations are computed with available experimental atomic data, except for photoionization and collision induced…

太阳与恒星天体物理 · 物理学 2015-05-20 Maria Bergemann

Determinations of the solar oxygen content relying on the neutral forbidden transition at 630 nm depend upon the nickel abundance, due to a Ni I blend. Here we rederive the solar nickel abundance, using the same ab initio 3D hydrodynamic…

天体物理学 · 物理学 2009-01-27 Pat Scott , Martin Asplund , Nicolas Grevesse , A. Jacques Sauval

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,…

太阳与恒星天体物理 · 物理学 2018-09-17 Sameh I. S , M. M. Beheary , Abdelrazek M. K. Shaltout

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…

太阳与恒星天体物理 · 物理学 2024-06-18 L. I. Mashonkina , T. A. Ryabchikova

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…

天体物理学 · 物理学 2009-07-09 M. Asplund , N. Grevesse , A. J. Sauval , C. Allende Prieto , D. Kiselman

We investigated the reliability of our silicon atomic model and the influence of non-local thermodynamical equilibrium (NLTE) on the formation of neutral silicon (Si I) lines in the near-infrared (near-IR) H-band. We derived the…

太阳与恒星天体物理 · 物理学 2016-10-20 Junbo Zhang , Jianrong Shi , Kaike Pan , Carlos Allende Prieto , Chao Liu

We investigate the feasibility of the Si I infrared (IR) lines as Si abundance indicators for giant stars. We find that Si abundances obtained from the Si I IR lines based on the local thermodynamic equilibrium (LTE) analysis show large…

太阳与恒星天体物理 · 物理学 2016-05-25 Kefeng Tan , Jianrong Shi , Masahide Takada-Hidai , Yoichi Takeda , Gang Zhao

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…

太阳与恒星天体物理 · 物理学 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

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…

太阳与恒星天体物理 · 物理学 2015-05-13 E. Caffau , E. Maiorca , P. Bonifacio , R. Faraggiana , M. Steffen , H. -G. Ludwig , I. Kamp , M. Busso

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…

太阳与恒星天体物理 · 物理学 2015-05-20 Elisabetta Caffau , Rosanna Faraggiana , Hans-Günter Ludwig , Piercarlo Bonifacio , Matthias Steffen

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…

太阳与恒星天体物理 · 物理学 2014-12-17 Pat Scott , Martin Asplund , Nicolas Grevesse , Maria Bergemann , A. Jacques Sauval

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…

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