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The study of stellar parameters of planet-hosting stars, such as metallicity and chemical abundances, help us to understand the theory of planet formation and stellar evolution. Here, we present a catalogue of accurate stellar atmospheric…

Solar and Stellar Astrophysics · Physics 2015-03-11 S. Alves , L. Benamati , N. C. Santos , V. Zh. Adibekyan , S. G. Sousa , G. Israelian , J. R. De Medeiros , C. Lovis , S. Udry

In recent years a number of poorly studied chemical elements, such as phosphorus, sulphur, and strontium, have received special attention as important tracers of the Galactic chemical evolution. By exploiting the capabilities of the…

Solar and Stellar Astrophysics · Physics 2015-12-16 E. Caffau , S. Andrievsky , S. Korotin , L. Origlia , E. Oliva , N. Sanna , H. -G. Ludwig , P. Bonifacio

Oxygen abundances for a large sample of dwarf and giant stars kinematically selected to be part of the Galactic thin and thick disks have been determined from a non-LTE analysis of the O I triplet lines at 777 nm. The abundance analysis was…

Astrophysics · Physics 2009-11-11 I. Ramirez , C. Allende Prieto , D. L. Lambert

HARPS spectra with signal-to-noise ratios S/N > 600 at 6000 A were analysed with MARCS model atmospheres to obtain 1D LTE abundances of C, O, Na, Mg, Al, Si, Ca, Ti, Cr, Fe, Ni, Sr, and Y for 72 nearby solar-type stars with metallicities in…

Solar and Stellar Astrophysics · Physics 2020-08-19 P. E. Nissen , J. Christensen-Dalsgaard , J. R. Mosumgaard , V. Silva Aguirre , E. Spitoni , K. Verma.

Gaia Bp/Rp spectra for over two hundred million stars have great potential for mapping metallicity across the Milky Way. We aim to construct an alternative catalog of atmospheric parameters from Gaia Bp/Rp spectra by fitting them with…

The inference of stellar parameters (such as radius and mass) through asteroseismic forward modelling depends on the number, accuracy, and precision of seismic and atmospheric constraints. ESA's Gaia space mission is providing precise…

Solar and Stellar Astrophysics · Physics 2024-12-09 Benard Nsamba , Achim Weiss , Juma Kamulali

We present a new set of oscillator strengths for 142 FeII lines in the wavelength range 4000-8000 A. Our gf-values are both accurate and precise, because each multiplet was globally normalized using laboratory data (accuracy), while the…

Solar and Stellar Astrophysics · Physics 2009-11-13 Jorge Melendez , Beatriz Barbuy

Synthetic stellar spectra are extensively used for many different applications in astronomy, from stellar studies (such as in the determination of atmospheric parameters of observed stellar spectra), to extragalactic studies (e.g. as one of…

Solar and Stellar Astrophysics · Physics 2017-04-05 Jessica R. Kitamura , Lucimara P. Martins , Paula Coelho

We describe the technique of absorption line imaging of galaxy disks using the Taurus Tunable Filter on the Anglo-Australian Telescope and demonstrate its sensitivity to the behaviour of spectral features associated with Mg and Fe. Radial…

Astrophysics · Physics 2011-03-10 S. D. Ryder , Y. Fenner , B. K. Gibson

We present measurements of [Fe/H] for six M supergiant stars and three giant stars within 0.5 pc of the Galactic Center (GC) and one M supergiant star within 30 pc of the GC. The results are based on high-resolution (lambda / Delta lambda…

We compare abundances patterns in the Bulge for elements observed in stars and in planetary nebulae. Some alpha elements, like Mg and Ti, are overabundant respect to Fe, and others are not, like He, O, Si, S, Ar, Ca. The first ones favor a…

Astrophysics · Physics 2007-05-23 F. Cuisinier , J. Koppen , A. Acker , W. J. Maciel

In this paper, we aim to derive high-precision alpha-element abundances using CRIRES high-resolution IR spectra of 72 cool M giants of the inner Galactic bulge. Silicon, magnesium, and calcium abundances were determined by fitting a…

Astrophysics of Galaxies · Physics 2023-03-08 N. Nieuwmunster , G. Nandakumar , E. Spitoni , N. Ryde , M. Schultheis , R. M. Rich , P. S. Barklem , O. Agertz , F. Renaud , F. Matteucci

The structure, formation, and evolution of the Milky Way bulge is a matter of debate. Important diagnostics for discriminating between bulge models include alpha-abundance trends with metallicity, and spatial abundance and metallicity…

Astrophysics of Galaxies · Physics 2015-12-23 N. Ryde , M. Schultheis , V. Grieco , F. Matteucci , R. M. Rich , S. Uttenthaler

A variety of physical processes leading to different types of pulsations and chemical compositions is observed among A- and F-type stars. To investigate the underlying mechanisms responsible for these processes in stars with similar…

Solar and Stellar Astrophysics · Physics 2015-05-13 S. Hekker , Y. Fremat , P. Lampens , P. De Cat , E. Niemczura , O. L. Creevey , J. Zorec

We have obtained [Mg/Fe] measurements for 76.3% of the stars in the MILES spectral library used for understanding stellar atmospheres and stellar populations in galaxies and star clusters. These abundance ratios were obtained through (1) a…

Solar and Stellar Astrophysics · Physics 2015-05-27 Andre de Castro Milone , Anne E. Sansom , Patricia Sanchez-Blazquez

Context. White dwarfs can be used to study the structure and evolution of the Galaxy by analysing their luminosity function and initial mass function. Among them, the very cool white dwarfs provide the information for the early ages of each…

Instrumentation and Methods for Astrophysics · Physics 2014-05-08 J. M. Carrasco , S. Catalán , C. Jordi , P. E. Tremblay , R. Napiwotzki , X. Luri , A. C. Robin , P. M Kowalski

We analyse the abundance ratios of the light elements Mg, Ca, C and N, relative to Fe, for 147 red-sequence galaxies in the Coma cluster and the Shapley Supercluster. The sample covers a six-magnitude range in luminosity, from giant…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Russell J. Smith , John R. Lucey , Michael J. Hudson , Terry J. Bridges

Context. The measurement of $\alpha$-elements abundances provides a powerful tool to put constraints on chemical evolution and star formation history of galaxies. The majority of studies on the $\alpha$-element Sulfur (S) are focused on…

Astrophysics of Galaxies · Physics 2021-12-22 F. Lucertini , L. Monaco , E. Caffau , P. Bonifacio , A. Mucciarelli

Atmospheric parameters determined via spectral modelling are unavailable for many of the known magnetic early B-type stars. We utilized high-resolution spectra together with NLTE models to measure effective temperatures $T_{\rm eff}$ and…

Solar and Stellar Astrophysics · Physics 2019-02-20 M. E. Shultz , G. A. Wade , Th. Rivinius , E. Alecian , C. Neiner , V. Petit , J. P. Wisniewski , the MiMeS , BinaMIcS Collaborations

Recent advances from astronomical surveys have revealed spatial, chemical, and kinematical inhomogeneities in the inner region of the stellar halo of the Milky Way Galaxy. In particular, large spectroscopic surveys, combined with Gaia…

Astrophysics of Galaxies · Physics 2020-07-08 Deokkeun An , Timothy C. Beers