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We investigate the formation of neutral and singly ionized scandium lines in the solar photospheres. The research is aimed derive solar $log gfepsilon_{odot}$(Sc) values for scandium lines, which will later be used in differential abundance analyses of metal-poor stars. Extensive statistical equilibrium calculations were carried out for a model atom, which comprises 92 terms for ion{Sc}{i} and 79 for ion{Sc}{ii}. Photoionization cross-sections are assumed to be hydrogenic. Synthetic line profiles calculated from the level populations according to the NLTE departure coefficients were compared with the observed solar spectral atlas. Hyperfine structure (HFS) broadening is taken into account. The statistical equilibrium of scandium is dominated by a strong underpopulation of ion{Sc}{i} caused by missing strong lines. It is nearly unaffected by the variation in interaction parameters and only marginally sensitive to the choice of the solar atmospheric model. Abundance determinations using the ODF model lead to a solar Sc abundance of between $logepsilon_odot = 3.07$ and 3.13, depending on the choice of $f$ values. The long known difference between photospheric and meteoritic scandium abundances is confirmed for the experimental $f$-values.
The determination of the birth radius of the Sun is important to understand the evolution and consequent disruption of the Suns birth cluster in the Galaxy. Motivated by this fact, we study the motion of the Sun in the Milky Way during the last 4.6 G
Exploration of superconductivity in light element compounds has drawn considerable attention because those materials can easily realize the high $T_{c}$ superconductivity, such as ${mathrm{LnNi}}_{2}{mathrm{B}_{2}}{mathrm{C}}$ ($T_{c}$ =17 K), ${math
We report the discovery of thermal X-ray emission from the youngest Galactic supernova remnant G1.9+0.3, from a 237-ks Chandra observation. We detect strong K-shell lines of Si, S, Ar, Ca, and Fe. In addition, we detect a 4.1 keV line with 99.971% co
The new version of TLUSTY allows for the calculation of restricted NLTE in cool stars using pre-calculated opacity tables. We demonstrate that TLUSTY gives consistent results with MULTI, a well-tested code for NLTE in cool stars. We use TLUSTY to per
Based on radiation hydrodynamics modeling of stellar convection zones, a diffusion scheme has been devised describing the downward penetration of convective motions beyond the Schwarzschild boundary (overshoot) into the radiative interior. This schem