Related papers: Detailed Opacity Calculations for Stellar Models
Opacity enhancements for stellar interior conditions have been explored to explain observed pulsation frequencies and to extend the pulsation instability region for B-type main-sequence variable stars. For these stars, the pulsations are…
We have developed a public code, Optab, that outputs Rosseland, Planck, and two-temperature Planck mean gas opacity tables for radiation hydrodynamics simulations in astrophysics. The code is developed for modern high-performance computing,…
Optical depths of dense molecular gas are commonly used in Galactic and extragalactic studies to constrain the dense gas mass of the clouds or galaxies. The optical depths are often obtained based on spatially unresolved data, especially in…
Rich oscillation spectra of dwarf-like pulsators contain a wealth of information about the object interiors and, in particular, about macroscopic transport processes, which is the most difficult aspect of stellar physics. Examples of…
There is observational evidence that central compact objects (CCOs) in supernova remnants have moderately strong magnetic fields $B\sim10^{11}$ G. Meanwhile, available models of partially ionized hydrogen atmospheres of neutron stars with…
Red supergiants are massive evolved stars that contribute extensively to the chemical enrichment of our Galaxy. It has been shown that convection in those stars gives rise to large granules that cause surface inhomogeneities and shock waves…
In the last decades, stellar atmosphere models have become a key tool in understanding massive stars. Applied for spectroscopic analysis, these models provide quantitative information on stellar wind properties as well as fundamental…
We investigate the correlations in galaxy shapes between optical and radio wavelengths using archival observations of the COSMOS field. Cross-correlation studies between different wavebands will become increasingly important for precision…
Context. Realistic 3D time-dependent simulations of stellar near-surface convection employ the opacity binning method for efficient and accurate computation of the radiative energy exchange. The method provides several orders of magnitude…
This paper presents an overview of the radiative transfer problem of calculating the spectral line intensity and polarization that emerges from a (generally magnetized) astrophysical plasma composed of atoms and molecules whose excitation…
We study some effects the inclusion of the radiation energy component in the universe, Omega_r, can have on several quantities of interest for the large-scale structure of the universe in a LCDM cosmological simulation; started at a very…
We construct seismic models of the four double-mode radial $\delta$ Scuti stars adopting opacities from three databases: OPAL, OP and OPLIB. The aim is to find the models that fit the observed frequencies of the two radial modes and have…
This review paper outlines background information and covers recent advances made via the analysis of spectra and images of prominence plasma and the increased sophistication of non-LTE (ie when there is a departure from Local Thermodynamic…
Context. The solar irradiance is known to change on time scales of minutes to decades, and it is suspected that its substantial fluctua- tions are partially responsible for climate variations. Aims. We are developing a solar atmosphere code…
Non-LTE radiative transfer is a key tool for modern astrophysics: it is the means by which many key synthetic observables are produced, thus connecting simulations and observations. Radiative transfer models also inform our understanding of…
Atomic diffusion with radiative levitation is a major transport process to consider to explain abundance anomalies in Am stars. Radiative accelerations vary from one species to another, yielding different abundance anomalies at the stellar…
The Petersen diagram is a frequently used tool to constrain model parameters such as metallicity of radial double-mode pulsators. In this diagram the period ratio of the radial first overtone to the fundamental mode, P_1/P_0, is plotted…
We test our knowledge of the atomic opacity in the solar UV spectrum. Using the atomic data compiled in Paper I from modern, publicly available, databases, we perform calculations that are confronted with space-based observations of the…
Contex. Stellar spectra synthesis is essential for the characterization of potential planetary hosts. In addition, comprehensive stellar variability calculations with fast radiative transfer are needed to disentangle planetary transits from…
Until very recently the physical mechanism driving oscillations in $\beta$~Cep and other early type stars has been a mystery. The breakthrough came with the publication of new OPAL and OP opacity data. Model calculations with the new…