相关论文: Non-LTE Equivalent Widths for NII with Error Estim…
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…
Medium resolution J-band spectroscopy of individual red supergiant stars is a promising tool to investigate the chemical composition of the young stellar population in star forming galaxies. As a continuation of recent work on iron and…
Non-local thermodynamic equilibrium (NLTE) line formation for neutral and singly-ionized iron is considered through a range of stellar parameters characteristic of cool stars. A comprehensive model atom for Fe I and Fe II is presented. Our…
We performed the non-local thermodynamic equilibrium (non-LTE) calculations for Ti I-II with the updated model atom that includes quantum-mechanical rate coefficients for inelastic collisions with hydrogen atoms. We have calculated for the…
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.…
Oxygen abundance measurements are important for understanding stellar structure and evolution. Measured in Cepheids, they further provide clues on the metallicity gradient and chemo-dynamical evolution in the Galaxy. However, most of the…
We present a detailed study of the non-Local Thermodynamic Equilibrium (non-LTE) formation of the high-excitation neutral oxygen 777 nm triplet in MARCS model atmospheres representative of late-type stars with spectral types F to K. We…
Aluminium abundances of B-type stars were spectroscopically determined in order to get information about the galactic gas composition at the time of their formation. For this purpose, two AlII lines at 6243 and 4663A were employed. The…
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…
Knowing accurate Pb abundances of metal-poor stars provides constraints on the Pb production mechanisms in the early Galaxy. Accurately deriving Th abundances permits a nucleo-chronometric age determination of the star. We improve the…
We perform the non-local thermodynamic equilibrium (NLTE) calculations for Ca I-II with the updated model atom that includes new quantum-mechanical rate coefficients for Ca I + H I collisions from two recent studies, that is, by Barklem and…
Detailed simultaneous radiative transfer-statistical equilibrium calculations have been performed for lithium in atmospheres of solar metallicity G-M dwarfs and subgiants. Model atmospheres of stars with $3500 \le \Tf \le 6000$ K, $3.0 \le…
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…
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 near-IR HeI 10830A transition is a highly sensitive diagnostic for non-LTE effects in the helium atom. So far, non-LTE line-formation computations have failed to quantitatively reproduce observations of this line in the entire range of…
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…
We present the results of determination of the barium abundance considering the non-LTE (NLTE) effects in 172 dwarf stars in the metallicity range of -1< [Fe/H] <+0.3, assigned to different Galactic substructures by kinematic criteria. We…
Detailed chemical abundances of very metal-poor (VMP, [Fe/H] < -2) stars are important for better understanding the First Stars, early star formation and chemical enrichment of galaxies. Big on-going and coming high-resolution spectroscopic…
The Ca~II H \& K lines are among the few features available to infer the metallicity of extremely metal-poor stars from medium-resolution spectroscopy. Unfortunately, these lines can overlap with absorption produced in the intervening…
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…