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Related papers: Non-LTE Radiative Transfer with Turbospectrum

200 papers

We describe the first results from our project aimed at large-scale calculations of NLTE abundance corrections for important astrophysical atoms and ions. In this paper, the focus is on Fe which is a proxy of stellar metallicity and is…

Solar and Stellar Astrophysics · Physics 2015-05-30 Maria Bergemann , Karin Lind , Remo Collet , Martin Asplund

The advent of new and more powerful infrared spectrographs has significantly motivated the advancement of the study of atomic and molecular line lists and stellar atmosphere models. While optical abundance determinations rely on extensively…

Transmission spectroscopy is one of the premier methods used to probe the temperature, composition, and cloud properties of exoplanet atmospheres. Recent studies have demonstrated that the multidimensional nature of exoplanet atmospheres --…

Earth and Planetary Astrophysics · Physics 2022-04-20 Ryan J. MacDonald , Nikole K. Lewis

We present an updated version of SKIRT, a 3D Monte Carlo radiative transfer code developed to simulate dusty galaxies. The main novel characteristics of the SKIRT code are the use of a stellar foam to generate random positions, an efficient…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Maarten Baes , Joris Verstappen , Ilse De Looze , Jacopo Fritz , Waad Saftly , Edgardo Vidal Pérez , Marko Stalevski , Sander Valcke

Planetary studies demand precise and accurate stellar parameters as input to infer the planetary properties. Different methods often provide different results that could lead to biases in the planetary parameters. In this work, we present a…

Solar and Stellar Astrophysics · Physics 2014-10-22 M. Tsantaki , S. G. Sousa , N. C. Santos , M. Montalto , E. Delgado-Mena , A. Mortier , V. Adibekyan , G. Israelian

We have developed a radiative transfer code, CMFGEN, which allows us to model the spectra of massive stars and supernovae. Using CMFGEN we can derive fundamental parameters such as effective temperatures and surface gravities, derive…

High Energy Astrophysical Phenomena · Physics 2015-05-27 D. John Hillier

The copper abundances of 29 metal-poor stars are determined based on the high resolution, high signal-to-noise ratio spectra from the UVES spectragraph at the ESO VLT telescope. Our sample consists of the stars of the Galactic halo, thick-…

Solar and Stellar Astrophysics · Physics 2018-08-08 J. R. Shi , H. L. Yan , Z. M. Zhou , G. Zhao

We investigated the copper abundances for $64$ late-type stars in the Galactic disk and halo with effective temperatures from $5400$ K to $6700$ K and [Fe/H] from $-1.88$ to $-0.17$. For the first time, the copper abundances are derived…

Solar and Stellar Astrophysics · Physics 2015-06-24 H. L. Yan , J. R. Shi , G. Zhao

Strontium has proven itself to be one of the most important neutron-capture elements in the study of metal-poor stars. Thanks to the strong absorption lines of Sr, they can be detected even in the most metal-poor stars and also in…

We present a new grid of LTE model atmospheres for weakly magnetic (B<=10e10G) neutron stars, using opacity and equation of state data from the OPAL project and employing a fully frequency- and angle-dependent radiation transfer. We discuss…

Astrophysics · Physics 2009-11-07 B. T. Gaensicke , T. M. Braje , R. W. Romani

To reproduce the observed spectra and light curves originated in the neighborhood of compact objects requires accurate relativistic ray-tracing codes. In this work, we present Skylight, a new numerical code for general-relativistic ray…

High Energy Astrophysical Phenomena · Physics 2022-07-07 Joaquín Pelle , Oscar Reula , Federico Carrasco , Carlos Bederian

Context. The pursuit of more realistic spectroscopic modelling and consistent abundances has led us to begin a new series of papers designed to improve current solar and stellar abundances of various atomic species. To achieve this, we have…

Solar and Stellar Astrophysics · Physics 2020-02-12 A. J. Gallagher , M. Bergemann , R. Collet , B. Plez , J. Leenaarts , M. Carlsson , S. A. Yakovleva , A. K Belyaev

Non-local thermodynamical equilibrium (NLTE) line formation for Mg I and Mg II lines is considered in classical 1D-LTE model atmospheres of the Sun and 17 stars with reliable atmospheric parameters and in a broad range of spectral types:…

Solar and Stellar Astrophysics · Physics 2018-10-31 Sofya Alexeeva , Tatiana Ryabchikova , Lyudmila Mashonkina , Shaoming Hu

In the aim of determining accurate iron abundances in stars, this work is meant to empirically calibrate H-collision cross-sections with iron, where no quantum mechanical calculations have been published yet. Thus, a new iron model atom has…

Solar and Stellar Astrophysics · Physics 2016-09-30 Rana Ezzeddine , Thibault Merle , Bertrand Plez

The aim of this study is to analyse and determine elemental abundances for a large sample of distant B stars in the outer Galactic disk in order to constrain the chemical distribution of the Galactic disk and models of chemical evolution of…

Solar and Stellar Astrophysics · Physics 2015-06-22 G. A. Bragança , T. Lanz , S. Daflon , K. Cunha , C. D. Garmany , J. W. Glaspey , M. Borges Fernandes , M. S. Oey , T. Bensby , I. Hubeny

The program package SME (Spectroscopy Made Easy), designed to perform an analysis of stellar spectra using spectral fitting techniques, was updated due to adding new functions (isotopic and hyperfine splittins) in VALD and including grids…

Instrumentation and Methods for Astrophysics · Physics 2017-10-31 N. Piskunov , T. Ryabchikova , Yu. Pakhomov , T. Sitnova , S. Alexeeva , L. Mashonkina , T. Nordlander

We model the transport of cosmic ray nuclei in the Galaxy by means of a new numerical code. Differently from previous numerical models we account for a generic spatial distribution of the diffusion coefficient. We found that in the case of…

Astrophysics · Physics 2016-05-19 C. Evoli , D. Gaggero , D. Grasso , L. Maccione

We present a new radiative transfer code for axi-symmetric stellar atmospheres and compare test results against 1D and 2D models with and without velocity fields. The code uses the short characteristic method with modifications to handle…

Astrophysics · Physics 2009-11-11 J. Zsargo , D. J. Hillier , L. N. Georgiev

Older GCE models predict [K/Fe] ratios as much as 1 dex lower than those inferred from stellar observations. Abundances of potassium are mainly based on analyses of the 7698 $\AA$ resonance line, and the discrepancy between models and…

Context: Radiative feedback plays a crucial role in the formation of massive stars. The implementation of a fast and accurate description of the proceeding thermodynamics in pre-stellar cores and evolving accretion disks is therefore a main…

Solar and Stellar Astrophysics · Physics 2015-03-13 Rolf Kuiper , Hubert Klahr , Cornelis Dullemond , Wilhelm Kley , Thomas Henning
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