Related papers: Uncertainties in (E)UV model atmosphere fluxes
The spectra arising from the disks of nova-like variables show many of the features seen in stellar atmospheres. They are typically modelled either from an appropriated weighted set of stellar atmospheres or a disk atmosphere with energy is…
We use a spherical non-LTE fully line blanketed model atmosphere to fit the full multi-wavelength spectrum, including the extreme ultraviolet (EUV) continuum observed by the {\it Extreme Ultraviolet Explorer}, of the B2 II star \epscma. The…
Observation of coronal EUV spectral lines sensitive to different temperatures offers an opportunity to evaluate the thermal structure and flows in flaring atmospheres. This can be used to estimate the partitioning between the thermal and…
WMAP data when combined with ancillary data on free-free, synchrotron and dust allow an improved understanding of the spectrum of emission from each of these components. Here we examine the sky variation at intermediate latitudes using a…
We reinvestigate the UV spectrum of NGC1535 by means of recently developed fully line-blanketed non-LTE models. These new models account for the wind in spherical geometry while handling the atomic data in a very similar way to the TLUSTY…
WMAP data when combined with ancillary data on free-free, synchrotron and dust allow an improved understanding of the spectrum of emission from each of these components. Here we examine the sky variation at intermediate and high latitudes…
Featureless optical and ultraviolet (UV) spectra are a puzzling signature to emerge from recent observations of luminous fast blue optical transients (LFBOTs) and some tidal disruption events (TDEs). We describe the landscape of source and…
We present a comprehensive analysis of high-resolution, far-UV HST/STIS, FUSE, and optical spectra of 17 O stars in the SMC. Our analysis is based on NLTE metal line-blanketed model atmospheres calculated with our NLTE code TLUSTY. We…
Extreme ultraviolet (EUV) radiations (10--117 nm) from host stars play important roles in the ionization, heating, and mass loss from exoplanet atmospheres. Together with the host star's Lyman-alpha and far-UV (117--170 nm) radiation, EUV…
The intensity of the Cosmic UV background (UVB), coming from all sources of ionising photons such as star-forming galaxies and quasars, determines the thermal evolution and ionization state of the intergalactic medium (IGM) and is,…
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…
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…
Since the prediction of climate is mainly considered as a prediction of second kind, it is indispensable to assess the accuracy with which these boundary conditions can be determined so that we can find a reasonable answer, whether climate…
UV, optical, and near-IR spectra of Vega have been combined to test our understanding of stellar atmospheric opacities, and to examine the possibility of constraining chemical abundances from low-resolution UV fluxes. We have carried out a…
The TIRAMISU code, a new program for computing on-the-fly non-LTE molecular spectra and opacities for solving self-consistent radiative transfer problems in exoplanet atmospheres, is presented. The ultra-hot Jupiter KELT-20 b is used as a…
Based on a simple thermodynamical argument, we proposed a unified cloudy model (UCM) with a warm dust cloud deep in the photosphere. We showed, for the first time, that a single grid of model photospheres (Teff between 800 and 2600K) offers…
A new dataset of atomic oxygen and molecular nitrogen number density profiles, along with thermospheric temperature profiles between 180 and 500 km, has been developed. These profiles are derived from solar occultation measurements made by…
We present a brief description of the newly upgraded versions of the programs TLUSTY, version 208, and SYNSPEC, version 54. TLUSTY is used to generate model stellar atmospheres or accretion disks, and SYNSPEC produces detailed synthetic…
It is generally accepted that the atmospheres of cool/lukewarm stars of spectral types A and later are described well by LTE model atmospheres, while the O-type stars require a detailed treatment of NLTE effects. Here model atmosphere…
FUSE spectra of star-forming regions in nearby galaxies are compared to composite spectra of Lyman-break galaxies (LBGs), binned by strength of Lyman alpha emission and by mid-UV luminosity. Several far-UV spectral features, including lines…