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Related papers: The NewEra model grid

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We present a grid of optical (3200--7200 \AA) synthetic spectra calculated with Tlusty/Synspec. The new NLTE model atmospheres include the most recent hydrogen Stark broadening profiles; were calculated in opacity sampling and limited to…

Solar and Stellar Astrophysics · Physics 2013-08-02 Peter Nemeth , Roy Østensen , Pier-Emmanuel Tremblay , Ivan Hubeny

Modern tools for modeling stellar evolution, such as MESA (Modules for Experiments in Stellar Astrophysics), offer state-of-the-art implementations of stellar theories. However, this parametric approach introduces many free parameters that…

Solar and Stellar Astrophysics · Physics 2026-02-10 O. Ziółkowska , R. Smolec , A. Thoul , R. Singh Rathour , V. Hocdé

Convective motions in solar-type stellar atmospheres induce Doppler shifts that affect the strengths and shapes of spectral absorption lines and create slightly asymmetric line profiles. 1D LTE studies of elemental abundances are not able…

Solar and Stellar Astrophysics · Physics 2018-10-10 G. Harutyunyan , M. Steffen , A. Mott , E. Caffau , G. Israelian , J. I. González Hernández , K. G. Strassmeier

Present grids of stellar atmosphere models are the workhorses in interpreting stellar observations, and determining their fundamental parameters. These models rely on greatly simplified models of convection, however, lending less predictive…

Solar and Stellar Astrophysics · Physics 2015-06-15 Regner Trampedach , Martin Asplund , Remo Collet , Åke Nordlund , Robert F. Stein

In this paper we investigate statistical equilibrium of Ti in the atmospheres of late-type stars. The Ti I/Ti II level populations are computed with available experimental atomic data, except for photoionization and collision induced…

Solar and Stellar Astrophysics · Physics 2015-05-20 Maria Bergemann

We describe our implementation of an extremely detailed model atom of singly ionized iron for NLTE computations in static and moving astrophysical plasmas. Our model atom includes 617 levels, 13675 primary permitted transitions and up to…

Astrophysics · Physics 2015-06-24 Peter H. Hauschildt , E. Baron

We present new ultra-metal-poor (UMP) stars parameters with [Fe/H]<-4.0 based on line-by-line non-local thermodynamic equilibrium (NLTE) abundances using an up-to-date iron model atom with a new recipe for non-elastic hydrogen collision…

Solar and Stellar Astrophysics · Physics 2017-10-11 Rana Ezzeddine , Anna Frebel , Bertrand Plez

One of the major tasks in interpretation of data from large-scale stellar surveys is to determine the fundamental atmospheric parameters such as effective temperature, surface gravity, and metallicity. In most on-going and upcoming…

Solar and Stellar Astrophysics · Physics 2015-06-16 L. Mashonkina

We present semi-empirical model chromospheres computed with the atmosphere code PHOENIX. The models are designed to fit the observed spectra of five mid- to late-type M dwarfs. Next to hydrogen lines from the Balmer series we used various…

Astrophysics · Physics 2009-11-11 B. Fuhrmeister , J. H. M. M. Schmitt , P. H. Hauschildt

We have analyzed the early optically thick ultraviolet spectra of Nova OS And 1986 using a grid of spherically symmetric, non-LTE, line-blanketed, expanding model atmospheres and synthetic spectra with the following set of parameters:…

We describe the atomic and molecular data that were used for the abundance analyses of FGK-type stars carried out within the Gaia-ESO Survey. We present an unprecedented effort to create a homogeneous line list, which was used by several…

A non-LTE (NLTE) abundance analysis was carried out for three extreme helium stars (EHes): BD+10 2179, BD-9 4395, and LS IV+6 002, from their optical spectra with NLTE model atmospheres. NLTE TLUSTY model atmospheres were computed with H,…

Solar and Stellar Astrophysics · Physics 2015-05-20 Gajendra Pandey , David L. Lambert

A contact interaction analysis is presented to search for new phenomena beyond the Standard Model in deep inelastic $e^\pm p \rightarrow e^\pm \, hadrons$ scattering. The data are collected with the H1 detector at HERA and correspond to…

High Energy Physics - Experiment · Physics 2012-08-27 H1 Collaboration

We study the implications of averaging methods with different reference depth scales for 3D hydrodynamical model atmospheres computed with the Stagger-code. The temporally and spatially averaged (hereafter denoted as <3D>) models are…

Solar and Stellar Astrophysics · Physics 2015-06-16 Zazralt Magic , Remo Collet , Wolfgang Hayek , Martin Asplund

Luminous BA-SGs allow topics ranging from NLTE physics and the evolution of massive stars to the chemical evolution of galaxies and cosmology to be addressed. A hybrid NLTE technique for the quantitative spectroscopy of BA-SGs is discussed.…

Astrophysics · Physics 2009-11-11 N. Przybilla , K. Butler , S. R. Becker , R. P. Kudritzki

We carried out a critical appraisal of the two theoretical models, Kurucz' ATLAS9 and PHOENIX/NextGen, for stellar atmosphere synthesis. Our tests relied on the theoretical fit of SEDs for a sample of 334 target stars along the whole…

Astrophysics · Physics 2009-11-10 E. Bertone , A. Buzzoni , M. Chavez , L. H. Rodriguez-Merino

Atmospheric parameters and chemical compositions for ten stars with metallicities in the region of -2.2< [Fe/H] <-0.6 were precisely determined using high resolution, high signal to noise, spectra. For each star the abundances, for 14 to 27…

The occurrence of multiple stars, dominantly binaries, is studied using the \textit{Gaia}-ESA DR2 catalogue. We apply the optimized statistical method that we previously developed for the analysis of 2D patterns. The field of stars is…

Astrophysics of Galaxies · Physics 2022-01-05 Petr Zavada , Karel Píška

Integrated light from distant galaxies is often compared to stellar population models via the equivalent widths of spectral features--spectral indices--whose strengths rely on the abundances of one or more elements. Such comparisons hinge…

Astrophysics · Physics 2009-06-23 A. Dotter , B. Chaboyer , J. W. Ferguson , H. -c. Lee , G. Worthey , E. Baron , D. Jevremovic