Related papers: LTE model atmopsheres MARCS, ATLAS and CO5BOLD
We investigate the observable characteristics of the extended atmospheres of AGB stars across a wide range of radio and (sub-)mm wavelengths using state-of-the-art 1D dynamical atmosphere and wind models over one pulsation period. We also…
Three-dimensional radiation-hydrodynamics (3D RHD) simulations of stellar surface convection provide valuable insights into many problems in solar and stellar physics. However, almost all 3D near-surface convection simulations to date are…
Models of thermal emission of neutron stars, presumably formed in their atmospheres, are needed to infer the surface temperatures, magnetic fields, chemical composition, and neutron star masses and radii from the observational data. This…
We have obtained ultra-high quality spectra (R=180,000; S/N>300) with unprecedented wavelength coverage (4400 to 7400 A) for a number of stars covering most of the HR diagram in order to test the predictions of models of stellar surface…
The correct interpretation of the large amount of complex data from next-generation (in particular, space-based) observational facilities requires a very strong theoretical underpinning. One can thus predict that in the near future the use…
The atmospheres of massive O-type stars (O stars) are dynamic, turbulent environments resulting from radiatively driven instabilities over the iron bump, located slightly beneath the stellar surface. Here, complex radiation hydrodynamic…
We describe a new method for the computation of opacity distribution functions (ODFs) useful to calculate one-dimensional model atmospheres in local thermal equilibrium (LTE). The new method is fast enough to be applied on current…
The Milky Way Galaxy is literally teeming with exoplanets; thousands of planets have been discovered, with thousands more planet candidates identified. Terrestrial-like planets are quite common around other stars, and are expected to be…
The OI 777 nm lines are among the most commonly used diagnostics for the oxygen abundances in the atmospheres of FGK-type stars. However, they form in conditions that are far from local thermodynamic equilibrium (LTE). We explore the…
Context - Exoplanetary upper atmospheres are low density environments where radiative processes can compete with collisional ones and introduce non-local thermodynamic equilibrium (NLTE) effects into transmission spectra. Aims - We develop…
We investigate the ability of both LTE and Non-LTE models to fit the near UV band absolute flux distribution and individual spectral line profiles of three standard stars for which high quality spectrophotometry and high resolution…
The influence of departures from local thermodynamic equilibrium (LTE) on neutral sulfur lines is considered. A grid of corrections is proposed to take into account the influence of departures from LTE for neutral sulfur lines in the…
We have taken K-band spectra covering 7 cooling flow clusters. The spectra show many of the 1-0S transitions of molecular Hydrogen, as well as some of the higher vibrational transitions, and some lines of ionized Hydrogen. The line ratios…
First results of the inversion of Stokes I and V profiles from plage regions near disk center are presented. Both low and high spatial resolution spectra of FeI 6301.5 and FeI 6302.5 A obtained with the Advanced Stokes Polarimeter (ASP)…
The knowledge of accurate stellar parameters is a key stone in several fields of stellar astrophysics, such as asteroseismology and stellar evolution. Although the parameters can be derived both via spectroscopy and multicolor photometry,…
We construct models of static, spherically symmetric shells supported by the radiation flux of a luminous neutron star in the Schwarzschild metric. The atmospheres are disconnected from the star and levitate above its surface. Gas pressure…
The paper describes the modelling of the structure and spectra of the hot accretion spots on the surface of young stars with taking into account departures from LTE for hydrogen and helium. It has been found that the existence of the ram…
A certain class of one-dimensional classical lattice models is considered. Using the method of abstract harmonic analysis explicit thermostatic properties of such models are derived. In particular, we discuss the low-temperature behavior of…
We present a detailed calculation of model atmospheres for DA white dwarfs. Our atmosphere code solves the atmosphere structure in local thermodynamic equilibrium with a standard partial linearization technique, which takes into account the…
In this research note, we outline the extension of the grid of upper atmosphere models first presented in Kubyshkina et al. (2018a). The original grid is based on a 1D hydrodynamic model and consists of about 7000 models covering planets of…