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Related papers: Fluorine Abundances in the Galactic Disk

200 papers

The proto-Milky Way epoch forms the earliest stars in our Galaxy and sets the initial conditions for subsequent disk formation. Recent observations from APOGEE and H3 surveys showed that the [$\alpha$/Fe] ratio slowly declined between…

Astrophysics of Galaxies · Physics 2024-11-11 Boquan Chen , Yuan-Sen Ting , Michael Hayden

We present chemical abundances of 57 metal-poor stars that are likely constituents of the outer stellar halo in the Milky Way. Almost all of the sample stars have an orbit reaching a maximum vertical distance (Z_max) of >5 kpc above and…

Astrophysics of Galaxies · Physics 2015-05-14 M. Ishigaki , M. Chiba , W. Aoki

We have investigated the abundance of several chemical elements in two large stellar samples kinematically representative of the thin and the thick disks of the Galaxy. Chemical, kinematical and age data have been collected from high…

Astrophysics · Physics 2007-05-23 Pascal Girard , Caroline Soubiran

We have derived elemental abundances of O, Na, Mg, Al, Si, Ca, Ti, Cr, Mn, Fe, Co, Ni for 47 G and K dwarf, with [Me/H]>0.1 dex. The selection of stars was based on their kinematics as well as on their uvby-photometry. One sample of stars…

Astrophysics · Physics 2009-10-30 Sofia Feltzing , Bengt Gustafsson

Neutral fluorine (F I) lines are identified in the optical spectra of cool EHe stars. These are the first identification of F I lines in a star's spectrum, and provide the first measurement of fluorine abundances in EHe stars. The results…

Astrophysics · Physics 2011-02-11 Gajendra Pandey

Context. The formation and evolution of the Milky Way bulge is still largely an unanswered question. One of the most essential observables needed in its modelling are the metallicity distribution and the trends of the alpha elements as…

Astrophysics of Galaxies · Physics 2014-12-10 N. Ryde , M. Schultheis

We examine the \alpha-element abundance ratio, [\alpha/Fe], of 5620 stars, observed by the Sloan Extension for Galactic Understanding and Exploration survey in the region 6 kpc < R < 16 kpc, 0.15 kpc < |Z| < 1.5 kpc, as a function of…

We report on high resolution spectroscopy of four giant stars in the Galactic old open clusters Berkeley~29 and Saurer~1 obtained with HIRES at the Keck telescope. These two clusters possess the largest galactocentric distances insofar…

In the light of the new observational data related to fluorine abundances in the solar neighborhood stars, we present here chemical evolution models testing different fluorine nucleosynthesis prescriptions with the aim to best fit those new…

Astrophysics of Galaxies · Physics 2018-04-18 E. Spitoni , F. Matteucci , H. Jönsson , N. Ryde , D. Romano

[ABRIDGED] Based on high-resolution (R~42000 to 48000) and high signal-to-noise (S/N~50 to 150) spectra obtained with UVES/VLT, we present detailed elemental abundances (O, Na, Mg, Al, Si, Ca, Ti, Cr, Fe, Ni, Zn, Y, and Ba) and stellar ages…

The earliest assembly of the Milky Way remains poorly understood, yet the spatial, chemical, and kinematic properties of its most metal-poor stars provide a unique fossil record of its proto-Galaxy phase. Understanding how this ancient…

We report results from a survey of neutral fluorine (F I) in the interstellar medium. Data from the Far Ultraviolet Spectroscopic Explorer (FUSE) were used to analyze 26 lines of sight lying both in the galactic disk and halo, including…

Astrophysics · Physics 2008-11-26 Theodore Snow , Joshua Destree , Adam Jensen

Context. Recent observations of the Bulge, e.g., its X-shape, cylindrical stellar motions, and a potential fraction of young stars propose that it formed through secular evolution of the disk and not through gas dissipation and/or mergers,…

Astrophysics of Galaxies · Physics 2019-05-29 M. Lomaeva , H. Jönsson , N. Ryde , M. Schultheis , B. Thorsbro

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

Fluorine is a fairly good tracer of formation histories of multiple stellar populations in globular clusters as already revealed by several studies. Large variations in fluorine abundance in red giant stars of the globular cluster M22 have…

Solar and Stellar Astrophysics · Physics 2015-06-17 P. de Laverny , A. Recio-Blanco

From exploratory studies and theoretical expectations it is known that simplifying approximations in spectroscopic analysis (LTE, 1D) lead to systematic biases of stellar parameters and abundances. These biases depend strongly on surface…

Solar and Stellar Astrophysics · Physics 2017-10-04 Maria Bergemann , Remo Collet , Ralph Schoenrich , Rene Andrae , Mikhail Kovalev , Gregory Ruchti , Camilla J. Hansen , Zazralt Magic

We have performed new determinations of sulphur and silicon abundances for a sample of 26 disk stars based on high-resolution, high signal-to-noise spectra. The results indicate a solar [S/Fe] for [Fe/H] >-0.3, below which [S/Fe] increases…

Astrophysics · Physics 2009-11-07 Y. Q. Chen , P. E. Nissen , G. Zhao , M. Asplund

We present Fe, Si, and Ca abundances for 61 giants in Plaut's Window (l=-1,b=-8.5) and Fe abundances for an additional 31 giants in a second, nearby field (l=0,b=-8) derived from high resolution (R~25,000) spectra obtained with the Blanco…

Solar and Stellar Astrophysics · Physics 2015-05-27 Christian I. Johnson , R. Michael Rich , Jon P. Fulbright , Elena Valenti , Andrew McWilliam

We present metallicities for 487 red giants in the Carina dwarf spheroidal (dSph) galaxy that were obtained from FLAMES low-resolution Ca triplet (CaT) spectroscopy. We find a mean [Fe/H] of -1.91 dex with an intrinsic dispersion of 0.25…

We discuss the detailed composition of 28 extremely metal-poor dwarfs, 22 of which are from the Hamburg/ESO Survey, based on Keck Echelle spectra. Our sample has a median [Fe/H] of -2.7 dex, extends to -3.5 dex, and is somewhat less…