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

200 papers

HST trigonometric distances, photometric metallicities, isochronic ages from the second revised version of the Geneva--Copenhagen survey, and uniform spectroscopic Fe and Mg abundances from our master catalog are used to construct and…

Astrophysics of Galaxies · Physics 2015-05-28 V. A. Marsakov , V. V. Koval' , T. V. Borkova , M. V. Shapovalov

Over the last few years, many studies have found an empirical relationship between the abundance of a star and its age. Here we estimate spectroscopic stellar ages for 178 825 red-giant stars observed by the APOGEE survey with a median…

Phosphorus (P) is a critical element for life on Earth yet the cosmic production sites of P are relatively uncertain. To understand how P has evolved in the solar neighborhood, we measured abundances for 163 FGK stars over a range of -1.09…

Solar and Stellar Astrophysics · Physics 2022-07-21 Z. G. Maas , K. Hawkins , N. R. Hinkel , P. Cargile , S. Janowiecki , T. Nelson

The compositions of stars are a critical diagnostic tool for many topics in astronomy such as the evolution of our Galaxy, the formation of planets, and the uniqueness of the Sun. Previous spectroscopic measurements indicate a large…

New information on the relations between the Galactic disks, the halo, and satellite galaxies is being obtained from elemental abundances of stars having metallicities in the range -1.5 < [Fe/H] < -0.5. The first results for a sample of 26…

Astrophysics · Physics 2015-05-13 Poul E. Nissen , William J. Schuster

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 trends of chemical abundances and abundance ratios observed in stars of different ages, kinematics, and metallicities bear the imprints of several physical processes that concur to shape the host galaxy properties. By inspecting these…

The distributions of a galaxy's gas and stars in chemical space encodes a tremendous amount of information about that galaxy's physical properties and assembly history. However, present methods for extracting information from chemical…

Astrophysics of Galaxies · Physics 2018-02-14 Mark R. Krumholz , Yuan-Sen Ting

Our current knowledge of star-forming metallicity relies primarily on gas-phase oxygen abundance measurements. This may not allow one to accurately describe differences in stellar evolution and feedback driven by variations in iron…

Astrophysics of Galaxies · Physics 2024-06-19 Martyna Chruślińska , Ruediger Pakmor , Jorryt Matthee , Tadafumi Matsuno

In addition to comprehensive surveys of the Milky Way bulge, disk, and halo, the Apache Point Galactic Evolution Experiment (APOGEE) project observed seven dwarf spheroidal satellites (dSphs) of the Milky Way: Carina, Sextans, Sculptor,…

We study the metal abundances of F and G type stars in the Galactic disk and halo using the Canada-France-Hawaii Telescope Legacy Survey D4 field. For a sample of stars within 7 kpc of the Galactic plane, we derive mean abundance values of…

Astrophysics · Physics 2009-11-13 Y. Karatas , M. Kilic , O. Gunes , F. Limboz

A study of the O/Fe ratio in metal-poor main sequence and subgiant stars is presented using the [OI] 6300A line, the OI 7774A triplet, and a selection of weak FeII lines observed on high-resolution spectra acquired with the VLT UVES…

Astrophysics · Physics 2009-11-07 P. E. Nissen , F. Primas , M. Asplund , D. L. Lambert

We present oxygen abundances for 72 F and G dwarf stars in the solar neighbourhood. Using the kinematics of the stars we divide them into two sub-samples with space velocities that are typical for the thick and thin disks, respectively. The…

Astrophysics · Physics 2009-11-10 T. Bensby , S. Feltzing , I. Lundstrom

We find two chemically distinct populations separated relatively cleanly in the [Fe/H] - [Mg/Fe] plane, but also distinguished in other chemical planes, among metal-poor stars (primarily with metallicities [Fe/H] $< -0.9$) observed by the…

We explore to which extent stars within Galactic disk open clusters resemble each other in the high-dimensional space of their photospheric element abundances, and contrast this with pairs of field stars. Our analysis is based on abundances…

We present a study of the chemical abundances of Solar neighbourhood stars associated to dynamical structures in the Milky Way's (thick) disk. These stars were identified as overdensity in the eccentricity range 0.3< ecc < 0.5 in the…

Astrophysics of Galaxies · Physics 2015-06-22 Amina Helmi , Mary Williams , K. C. Freeman , J. Bland-Hawthorn , G. De Silva

We present sodium abundances for a sample of nearby stars. All results have been derived from NLTE statistical equilibrium calculations. The influence of collisional interactions with electrons and hydrogen atoms is evaluated by comparison…

Astrophysics · Physics 2009-11-10 J. R. Shi , T. Gehren , G. Zhao

... We confirm the well-established differences for [$\alpha$/Fe] at a given metallicity between the local thin and thick disks. For all the elements investigated, we find no chemical distinction between the bulge and the local thick disk,…

Solar and Stellar Astrophysics · Physics 2015-05-18 A. Alves-Brito , J. Melendez , M. Asplund , I. Ramirez , D. Yong

Photospheric C, N, and O abundances of 118 solar-analog stars were determined by applying the synthetic-fitting analysis to their spectra in the blue or near-UV region comprising lines of CH, NH, and OH molecules, with an aim of clarifying…

Solar and Stellar Astrophysics · Physics 2023-02-01 Yoichi Takeda

The metallicity distribution function (MDF) of the Galactic bulge features a multi-peak shape, with a metal-poor peak at [Fe/H]=-0.3 dex and a metal-rich peak at [Fe/H]=+0.3 dex. This bimodality is also seen in [alpha/Fe] versus [Fe/H]…

Astrophysics of Galaxies · Physics 2024-05-22 M. Molero , F. Matteucci , E. Spitoni , A. Rojas-Arriagada , R. M. Rich