相关论文: Formation of Li I lines in photospheric granulatio…
The astrophysically very interesting Li I 671 nm line has been observed with high spatial resolution in solar granulation with the intention to diagnose departures from local thermodynamic equilibrium (LTE) in the line formation. The…
NLTE effects - the errors caused by assuming local thermodynamic equilibrium (LTE) - on LiBeB abundance determinations for cool stars are discussed. These NLTE effects are significant in many cases for B I and Li I lines. The Be II 313 nm…
Non-local thermodynamic equilibrium (NLTE) effects in diagnostically important solar Fe I lines are important due to the strong sensitivity of Fe I to ionizing UV radiation, which may lead to a considerable under-population of the Fe I…
Different simplified approaches are used to account for the non-local thermodynamic equilibrium (NLTE) effects with 3D hydrodynamical model atmospheres. In certain cases, chemical abundances are derived in 1D NLTE and corrected for the 3D…
We study the formation of B I lines in a grid of cool stellar model atmospheres without the assumption of local thermodynamic equilibrium (LTE). The non-LTE modelling includes the effect of other lines blending with the B I resonance lines.…
We investigate the effects of horizontal radiative transfer (RT) a NLTE on important diagnostic iron lines in a realistic 3-D HD simulation. Using a multi-level atom we compute and compare widely used Fe I line profiles at 3 different…
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…
Based on detailed 2D radiation hydrodynamics (RHD) simulations, we have investigated the effects of photospheric temperature inhomogeneities induced by convection on spectroscopic determinations of the lithium abundance. Computations have…
In an effort to estimate the largely unknown effects of photospheric temperature fluctuations on spectroscopic abundance determinations, we have studied the problem of LTE line formation in the inhomogeneous solar photosphere based on…
Earlier studies have suggested that deviations from the local thermodynamic equilibrium (LTE) play a minor role in the formation of Be II 313 nm resonance lines in solar and stellar atmospheres. Recent improvements in the atomic data allow…
This paper forms the second part of our study on how the neglect of NLTE conditions in the formation of Fe I 6301.5 A and the 6302.5 A lines influences the atmosphere obtained by inverting their profiles in LTE. The main cause of NLTE…
The current analysis is dedicated to a detailed investigation of the non-Local Thermodynamic Equilibrium (NLTE) effects influencing the formation of the Fe I 6173 A line, which is widely used by many instruments including the Helioseismic…
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…
In the first three papers of this series, we investigated the formation of photospheric neutral iron lines in different atmospheres ranging from idealised flux tube models to complex three-dimensional magnetohydrodynamic (3D MHD)…
We investigate departures from LTE in the line formation of Fe for a number of well-studied late-type stars in different evolutionary stages. A new model of Fe atom was constructed from the most up-to-date theoretical and experimental…
We perform non-LTE calculations of lithium in late-type stars for a wide range of stellar parameters, including quantum mechanical cross-sections for collisions with neutral hydrogen and the negative hydrogen ion. Non-LTE abundance…
Non-local thermodynamical equilibrium (NLTE) line formation for Mg I and Mg II lines is considered in classical 1D-LTE model atmospheres of the Sun and 17 stars with reliable atmospheric parameters and in a broad range of spectral types:…
Convective motions in solar-type stellar atmospheres induce Doppler shifts that affect the strengths and shapes of spectral absorption lines and create slightly asymmetric line profiles. 1D LTE studies of elemental abundances are not able…
The formation of the resonance lines of neutral boron in solar-type stellar atmospheres is investigated taking into account effects of departures from local thermodynamic equilibrium (NLTE effects). The latter are due to a combination of…
We construct a comprehensive model atom for TiI-II using more than 3600 measured and predicted energy levels of TiI and 1800 energy levels of TiII, and quantum mechanical photoionisation cross-sections. Non-local thermodynamical equilibrium…