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Related papers: New Grids of ATLAS9 Model Atmospheres

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We present atmospheric parameters for about 300 stars of different chemical composition, whose spectra will be used to study the galactic enrichment of Fe and light elements. These parameters were derived using an homogenous iterative…

Astrophysics · Physics 2007-05-23 R. G. Gratton , E. Carretta , F. Castelli

We present a new grid of model photospheres for the SDSS-III/APOGEE survey of stellar populations of the Galaxy, calculated using the ATLAS9 and MARCS codes. New opacity distribution functions were generated to calculate ATLAS9 model…

Context. Cool star model atmospheres are a common tool for the investigation of stellar masses, ages and elemental abundance composition. Theoretical atmospheric models strongly depend on the atomic data used when calculating them. Aims. We…

Solar and Stellar Astrophysics · Physics 2015-05-13 F. Grupp , R. L. Kurucz , K. Tan

New grids of Atlas9 models have been calculated using revised convection parameters and updated opacity-distribution functions, for chemical compositions intended to be representative of solar, [M/H] = +0.3, +0.5, Large Magellanic Cloud…

Solar and Stellar Astrophysics · Physics 2015-05-20 Ian D. Howarth

A grid of ATLAS9 model atmospheres has been computed, spanning 3500 K <= T_eff <= 8000 K, 0.0 <= log g <= 5.0, -4.0 <= [M/H] <= 0.0, and -0.8 < [alpha/Fe] <= +1.2. These parameters are appropriate for stars in the red giant branch, subgiant…

Solar and Stellar Astrophysics · Physics 2011-10-26 Evan N. Kirby

We present several new sets of grids of model stellar atmospheres computed with modified versions of the ATLAS9 code. Each individual set consists of several grids of models with different metallicities ranging from [M/H] = -2.0 to +1.0…

We present the KOALA database, a new set of LTE, line-blanketed model atmospheres calculated with the code ATLAS9, together with the corresponding Opacity Distribution Functions and emergent fluxes. The latter were used also to calculated…

Solar and Stellar Astrophysics · Physics 2025-11-17 A. Mucciarelli , P. Bonifacio , C. Lardo

The Space Telescope Imaging Spectrograph (STIS) has measured the spectral energy distributions (SEDs) for several stars of types O, B, A, F, and G. These absolute fluxes from the CALSPEC database are fit with a new spectral grid computed…

Solar and Stellar Astrophysics · Physics 2017-05-10 Ralph C. Bohlin , Szabolcs Meszaros , Scott W. Fleming , Karl D. Gordon , Anton M. Koekemoer , Jozsef Kovacs

We present equivalent widths, improved model atmosphere parameters, and revised abundances for 14 species of 11 elements derived from high resolution optical spectroscopy of 311 metal-poor stars. All of these stars had their parameters…

Solar and Stellar Astrophysics · Physics 2025-02-27 Sanil Mittal , Ian U. Roederer

We have constructed a grid of about 10,000 spherically symmetric and plane-parallel models with the MARCS program, and make it available for public use. Parameter ranges are: Teff=2500 to 8000 K, log g =log(GM/R2)= -1 to 5 (cgs) with…

Lithium abundances in a sample of halo dwarfs have been redetermined by using the new T$_{eff}$ derived by Fuhrmann et al (1994) from modelling of the Balmer lines. These T$_{eff}$ are reddening independent, homogeneous and of higher…

Astrophysics · Physics 2007-05-23 P. Molaro , F. Primas , P. Bonifacio

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…

Astrophysics · Physics 2007-05-23 F. Kupka , N. E. Piskunov

We present a grid of spherically symmetric model atmospheres for young pre-MS stars. This grid spans the parameter range $2000\K \leq \Teff \leq 6800\K$ and $2.0 \leq \logg \leq 3.5$ for $M=0.1\Msun$, appropriate for low mass stars and…

Astrophysics · Physics 2010-04-29 France Allard , Peter H. Hauschildt , Andreas Schweitzer

We performed a uniform and detailed analysis of 1112 high-resolution spectra of FGK dwarfs obtained with the HARPS spectrograph at the ESO 3.6 m telescope (La Silla, Chile). Most stars have effective temperatures 4700 K < Teff < 6300 K and…

Astrophysics of Galaxies · Physics 2011-11-22 V. Zh. Adibekyan , N. C. Santos , S. G. Sousa , G. Israelian

The measurement of oxygen lines in metal-poor unevolved stars, in particular near-UV OH lines, can provide invaluable information on the properties of the Early Galaxy. Near-UV OH lines constitute an important tool to derive oxygen…

Astrophysics of Galaxies · Physics 2015-05-19 J. I. Gonzalez Hernandez , P. Bonifacio , H. -G. Ludwig , E. Caffau , N. T. Behara , B. Freytag

We compare the structures of model atmospheres and synthetic spectra calculated using different line lists for TiO and water vapor. We discuss the effects of different line list combinations on the model strutures and spectra for both dwarf…

Astrophysics · Physics 2010-05-17 France Allard , Peter H. Hauschildt , David Schwenke

S-type stars are late-type giants whose atmosphere is enriched in carbon and s-process elements because of either extrinsic pollution by a binary companion or intrinsic nucleosynthesis and dredge-up on the thermally-pulsing AGB. A large…

We present the analysis of an extensive set of new and literature high quality data concerning Fe, C, N, O, Na, and Mg, exploiting the Teff scale determined in Gratton et al. (1996), and the non-LTE abundance corrections computed in Gratton…

Astrophysics · Physics 2007-05-23 Eugenio Carretta , Raffaele Gratton , Chris Sneden

We report the first survey of chemical abundances in M and K dwarf stars using atomic absorption lines in high resolution spectra. We have measured Fe and Ti abundances in 35 M and K dwarf stars using equivalent widths measured from (lambda…

Astrophysics · Physics 2009-11-10 Vincent M. Woolf , George Wallerstein

An extremely high-resolution (> 10^5) high-S/N (> 10^3) solar spectrum has been used to measure 15 very weak first overtone (Delta v = 2) infrared OH lines, resulting in a low solar abundance of A(O) ~ 8.6 when MARCS, 3D, and spatially and…

Astrophysics · Physics 2009-11-10 Jorge Melendez
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