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Related papers: Abundance trends in the inner and outer Galactic d…

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[ABRIDGED] We determine Li abundances for a well-studied sample of 714 F and G dwarf, turn-off, and subgiant stars in the solar neighbourhood. The analysis is based on line synthesis of the Li line at 6707 {\AA} in high-resolution and high…

Astrophysics of Galaxies · Physics 2018-08-01 Thomas Bensby , Karin Lind

The Galactic bulge, that is the prominent out-of-plane over-density present in the inner few kiloparsecs of the Galaxy, is a complex structure, as the morphology, kinematics, chemistry and ages of its stars indicate. To understand the…

Astrophysics of Galaxies · Physics 2016-07-06 P. Di Matteo

We have studied 23 long-lived G dwarfs that belong to the thin disk and thick disk stellar populations. Abundances have been derived for 24 elements: O, Na, Mg, Al, Si, Ca, Ti, Sc, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, La, Ce, Nd,…

Astrophysics · Physics 2008-11-26 Mary-Margaret Brewer , Bruce W. Carney

We present a panoptic view of the stellar structure in the Galactic disk's outer reaches commonly known as the Monoceros Ring, based on data from Pan-STARRS1. These observations clearly show the large extent of the stellar overdensities on…

Recent spectroscopic observations in the Milky Way suggest that the chemically defined thick disk (stars with high [alpha/Fe] ratios and thus old) has a significantly smaller scale-length than the thin disk. This is in apparent…

Astrophysics of Galaxies · Physics 2015-06-24 I. Minchev , M. Martig , D. Streich , C. Scannapieco , R. S. de Jong , M. Steinmetz

We test competing models that aim at explaining the nature of stars in the Milky Way that are well away (|z|$\gtrsim$ 1kpc) from the midplane, the so-called thick disk: the stars may have gotten there through orbital migration, through…

Astrophysics of Galaxies · Physics 2015-05-19 Marion Dierickx , Rainer J. Klement , Hans-Walter Rix , Chao Liu

We present the Galactic model parameters for thin disc estimated by Sloan Digital Sky Survey (SDSS) data of 14 940 stars with apparent magnitudes $16<g_{o}\leq21$ in six intermediate latitude fields in the first Galactic quadrant.…

Astrophysics · Physics 2009-11-11 S. Bilir , S. Karaali , S. Ak , E. Yaz , E. Hamzaoglu

Photospheric abundances are presented for 27 elements from carbon to europium in 181 F-G dwarfs from a differential LTE analysis of high-resolution and high signal-to-noise spectra. Stellar $T_{\rm eff}$ were adopted from an infrared flux…

Astrophysics · Physics 2009-11-07 Bacham E. Reddy , Jocelyn Tomkin , David L. Lambert , Carlos Allende Prieto

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

The parameters and elemental abundances of atmospheres for ten thick-disk red giants was determined from high-resolution spectra by the method of model stellar atmospheres. The results of a comparative analysis of the [Na/Fe] abundances in…

Solar and Stellar Astrophysics · Physics 2013-12-12 Yu. V. Pakhomov

The recently emerging conviction that thick disks are prevalent in disk galaxies, and their seemingly ubiquitous old ages, means that the formation of the thick disk, perhaps more than any other component, holds the key to unravelling the…

Astrophysics · Physics 2009-11-10 Chris B. Brook , Brad K. Gibson , Hugo Martel , Daisuke Kawata

We aim at studying the abundance gradients along the Galactic disk and their dependence upon several parameters: a threshold in the surface gas density regulating star formation, the star formation efficiency, the timescale for the…

Astrophysics · Physics 2009-11-13 E. Colavitti , G. Cescutti , F. Matteucci , G. Murante

The Milky Way is widely considered to exhibit features of a rotational bar or quadrupole bar. In either case, the feature of the resonance of the Galactic bar should be present in the properties of the chemistry and kinematics, over a large…

Astrophysics of Galaxies · Physics 2024-04-09 Weixiang Sun , Han Shen , Biwei Jiang , Xiaowei Liu

In this work, a sample of planetary nebulae located in the inner-disk and bulge of the Galaxy is used in order to find the galactocentric distance which better separates these two populations, from the point of view of abundances.…

Astrophysics of Galaxies · Physics 2011-01-18 O. Cavichia , R. D. D. Costa , W. J. Maciel

We analyse a 10,000 star spectroscopic survey, focused on Galactic thick disk stars typically 2-5 kpc from the Sun, carried out using the AAOmega Spectrograph on the AAT. We develop methods for completeness-correction of the survey based on…

Astrophysics of Galaxies · Physics 2015-06-15 Apoorva Jayaraman , Gerard Gilmore , Rosemary F. G. Wyse , John E. Norris , Vasily Belokurov

The abundance of fluorine is determined from the (2-0) R9 2.3358 micron feature of the molecule HF for several dozen normal G and K stars in the Galactic thin disk from spectra obtained with the Phoenix IR spectrometer on the 2.1-m…

Solar and Stellar Astrophysics · Physics 2015-08-19 Catherine A. Pilachowski , Cameron Pace

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

High-resolution spectra of 13 core helium-burning stars in the thick disk of the Galaxy have been obtained with the SOFIN spectrograph on the Nordic Optical Telescope to investigate abundances of up to 22 chemical elements. Abundances of…

Astrophysics · Physics 2009-11-07 G. Tautvaisiene , B. Edvardsson , I. Tuominen , I. Ilyin

Exoplanet demographic surveys have revealed that close-in (${\lesssim}$1 au) small planets orbiting stars in the Milky Way's thick disk are ${\sim}50\%$ less abundant than those orbiting stars in the Galactic thin disk. One key difference…

Earth and Planetary Astrophysics · Physics 2024-12-10 Tim Hallatt , Eve J. Lee

The outer parts of the Milky Way disk are believed to be one of the main arenas where the accretion of external material in the form of dwarf galaxies and subsequent formation of streams is taking place. The Monoceros stream and the Canis…

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