Neutral nickel (Ni I) is abundant in the solar atmosphere and is one of the important elements that contribute to the emission and absorption of radiation in the spectral range between 1900 and 3900 A. Previously, the Solar Radiation Physical Modeling (SRPM) models of the solar atmosphere considered only few levels of this species. Here we improve the Ni I atomic model by taking into account 61 levels and 490 spectral lines. We compute the populations of these levels in full NLTE using the SRPM code and compare the resulting emerging spectrum with observations. The present atomic model improves significantly the calculation of the solar spectral irradiance at near-UV wavelengths that are important for Earth atmo spheric studies, and particularly for ozone chemistry.
Both the quality and amount of astrophysical data are steadily increasing over time owing to the improvement of telescopes and their instruments. This requires corresponding evolution of the techniques used for obtaining and analyzing the resulting data. The infrared spectral range at 1.56 $μ$m usually observed by the GRegor Infrared Spectrograph (GRIS) at the GREGOR solar telescope has a width of around 30 $Å$ and includes at least 15 spectral lines. Normally, only a handful of spectral lines (five at most) are used in studies using GRIS because of the lack of atomic parameters for the others…
Chromospheric polarimetry through multi-line observations of the 850 nm spectral region
未来的太阳任务和地面望远镜的目标是了解太阳色球层的磁性。我们在Quintero Noda等人（2016）中进行了一项支持性研究，重点是红外Ca II 8542 A线，我们得出结论认为这是最佳候选者之一，因为它对从光球层到中间色球层的大范围大气高度敏感。然而，我们认为，值得尝试改进由这条线观察到的额外谱线产生的结果。在这方面，我们研究了邻近的太阳光谱，寻找能够增加对大气参数敏感性的谱线。有趣的是，我们发现了几个光球线，大大提高了光球的灵敏度磁场矢量。此外，它们位于靠近第二色球线，也属于钙II红外三重态，即钙II 8498 A线，并提高了在色球层的大气参数的灵敏度。我们的结论是，在Ca II 8542 A线附近的线，不仅增加了它的灵敏度，在所有层的大气参数，但它们也构成了一个很好的光谱窗口色球偏振测量。
The Stokes profiles of Fe I lines in the photosphere of the Sun are calculated within the Unno-Beckers-Landi-Dagl`Innocenti theory. Estimates of the magnetic strengthening of the lines were obtained. The changes in the Stokes profiles depending on the excitation potential, wavelength, equivalent width, Lande factor, micro-macroturbulent velocities, radial velocity, damping constant, atmospheric model, magnetic field strength and direction are considered. The graphically presented variations of the Stokes profiles make it possible to determine the initial values of the input parameters for solv…
Transiting ultra-hot Jupiters are ideal candidates to study the exoplanet atmospheres and their dynamics, particularly by means of high-resolution, high signal-to-noise ratio spectra. One such object is KELT-20b, orbiting the fast rotating A2-type star KELT-20. Many atomic species have already been found in its atmosphere, with blueshifted signals that hints at the presence of a day-to-night side wind. We aimed to observe the atmospheric Rossiter-McLaughlin effect in the ultra-hot Jupiter KELT-20b, and to study any variation of the atmospheric signal during the transit. For this purpose, we an…
Improving the parametrization of transport and mixing processes in planetary atmospheres: the importance of implementing the full Coriolis acceleration
