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Related papers: Cosmic variance in [O/Fe] in the Galactic disk

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We have re-evaluated empirical expressions for the abundance determination of N, O, Ne, S, Cl, Ar and Fe taking into account the latest atomic data and constructing an appropriate grid of photoionization models with state-of-the art model…

Astrophysics · Physics 2009-07-28 Y. I. Izotov , G. Stasinska , G. Meynet , N. G. Guseva , T. X. Thuan

We determined the chemical and kinematic properties of the Galactic thin and thick disk using a sample of 307,246 A/F/G/K-type giant stars from the LAMOST spectroscopic survey and Gaia DR2 survey. Our study found that the thick disk…

Astrophysics of Galaxies · Physics 2019-07-31 Yepeng Yan , Cuihua Du , Shuai Liu , Hefan Li , Jianrong Shi , Yuqin Chen , Jun Ma , Zhenyu Wu

The detailed age-chemical abundance relations of stars measures time-dependent chemical evolution.These trends offer strong empirical constraints on nucleosynthetic processes, as well as the homogeneityof star-forming gas. Characterizing…

Astrophysics of Galaxies · Physics 2022-03-23 Yuxi , Lu , Melissa Ness , Tobias Buck , Joel Zinn

We present fundamental stellar parameters and chemical abundances for a sample of 86 evolved stars with planets and for a control sample of 137 stars without planets. The analysis was based on both high S/N and resolution echelle spectra.…

Earth and Planetary Astrophysics · Physics 2015-01-28 E. Jofré , R. Petrucci , C. Saffe , L. Saker , E. Artur de la Villarmois , C. Chavero , M. Gómez , P. Mauas

The variation of metal production over time and its dilution in the interstellar medium depend on the star formation and gas accretion rates. Measuring age-chemistry relations across the Milky Way disk provides key constraints on the gas…

Astrophysics of Galaxies · Physics 2025-05-28 Valeria Cerqui , Misha Haywood , Owain Snaith , Paola Di Matteo , Laia Casamiquela

We present radial velocities and chemical abundance ratios of [Fe/H], [O/Fe], [Si/Fe], and [Ca/Fe] for 264 red giant branch (RGB) stars in three Galactic bulge off-axis fields located near (l,b)=(-5.5,-7), (-4,-9), and (+8.5,+9). The…

We analyse the evolution of the oxygen abundance gradient of star-forming galaxies with stellar mass Mstar > 10^9 Mo in the EAGK simulation over the redshift range z=[0, 2.5]. We find that the median metallicity gradient of the simulated…

Astrophysics of Galaxies · Physics 2022-01-05 Patricia B. Tissera , Yetli Rosas-Guevara , Emanuel Sillero , Susana E. Pedrosa , Tom Theuns , Lucas Bignone

High resolution, high S/N spectra have been obtained for a sample of 90 F and G main-sequence disk stars covering the metallicity range -1.0 < [Fe/H] < +0.1, and have been analysed in a parallel way to the work of Edvardsson et al. (1993).…

Astrophysics · Physics 2009-10-31 Y. Q. Chen , P. E. Nissen , G. Zhao , H. W. Zhang , T. Benoni

We present radial velocities and chemical abundances for nine stars in the old, distant open clusters Be 18, Be 21, Be 22, Be 32, and PWM 4. For Be 18 and PWM 4, these are the first chemical abundance measurements. Combining our data with…

Astrophysics of Galaxies · Physics 2015-06-05 David Yong , Bruce W. Carney , Eileen D. Friel

We present Na, Mg and Al abundances in a set of 98 stars with known giant planets, and in a comparison sample of 41 ``single'' stars. The results show that the [X/H] abundances (with X = Na, Mg and Al) are, on average, higher in stars with…

Astrophysics · Physics 2009-11-10 P. Beirao , N. C. Santos , G. Israelian , M. Mayor

(Abridged) We have used the atmospheric parameters, [alpha/Fe] abundances and radial velocities, determined from the Gaia-ESO Survey GIRAFFE spectra of FGK-type stars (iDR1), to provide a chemo-kinematical characterisation of the disc…

We present homogeneous and accurate iron abundances for almost four dozen (47) of Galactic Cepheids using high-spectral resolution (R$\sim$40,000) high signal-to-noise ratio (S/N $\ge$ 100) optical spectra collected with UVES at VLT. A…

We investigate the properties of the double sequences of the Milky Way discs visible in the [$\alpha$/Fe] vs [Fe/H] diagram. In the framework of Galactic formation and evolution, we discuss the complex relationships between age,…

We have measured the Li abundance of 18 stars with -2 <~ [Fe/H] ~< -1 and 6000 K <~ Teff <~ 6400 K, a parameter range that was poorly represented in previous studies. We examine the Galactic chemical evolution (GCE) of this element,…

We present an analysis of the chemical abundance properties of $\approx$650 star-forming galaxies at $z \approx0.6-1.8$. Using integral-field observations from the $K$-band Multi-Object Spectrograph (KMOS), we quantify the [NII]/H$\alpha$…

Thanks to tremendous experimental efforts, galactic cosmic-ray fluxes are being measured up to the unprecedented per cent precision level. The logarithmic slope of these fluxes is a crucial quantity that promises us information on the…

High Energy Astrophysical Phenomena · Physics 2025-03-21 M. Vecchi , P. -I. Batista , E. F. Bueno , L. Derome , Y. Génolini , D. Maurin

We highlight some results from our detailed abundance analysis study of 703 kinematically selected F and G dwarf stars in the solar neighbourhood. The analysis is based on spectra of high-resolution (R=45000 to 110000) and high…

Astrophysics of Galaxies · Physics 2015-05-30 T. Bensby , S. Feltzing

We analyse for the first time the radial abundance gradients of the disc stars of a disc galaxy simulated with our three dimensional, fully cosmological chemodynamical galaxy evolution code GCD+. We study how [Fe/H], [N/O], [O/Fe], [Mg/Fe]…

Astrophysics of Galaxies · Physics 2015-05-27 Awat Rahimi , Daisuke Kawata , Carlos Allende Prieto , Chris B. Brook , Brad K. Gibson , Alina Kiessling

We present chemical evolution models of the Galactic disk with different Z-dependent yields. We find that a moderate mass loss rate for massive stars of solar metallicity produces an excellent fit to the observed C/H and C/O gradients of…

Astrophysics of Galaxies · Physics 2011-02-08 Leticia Carigi , Manuel Peimbert

We have performed a NLTE analysis of the infrared oxygen triplet for a large number of cepheid spectra obtained with the Hobby-Eberly telescope. These data were combined with our previous NLTE results for the stars observed with Max Planck…

Solar and Stellar Astrophysics · Physics 2014-08-27 S. A. Korotin , S. M. Andrievsky , R. E. Luck , J. R. D. Lepine , W. J. Maciel , V. V. Kovtyukh
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