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

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Over the last decade there have been a series of results supporting the hypothesis of the existence of a long thin bar in the Milky Way with a half-length of 4.5 kpc and a position angle of around 45 deg. This is apparently a very different…

Theories of thick disk formation can be differentiated by measurements of stellar elemental abundances. We have undertaken a study of metal-poor stars selected from the RAVE spectroscopic survey of bright stars to establish whether or not…

We have made the first attempt to derive the chemical properties of the Galactic disc at its very central part using high-resolution infrared spectroscopic observations of four classical Cepheids. Those stars are located at Galactocentric…

Astrophysics of Galaxies · Physics 2019-09-04 V. V. Kovtyukh , S. M. Andrievsky , R. P. Martin , S. A. Korotin , J. R. D. Lepine , W. J. Maciel , L. E Keir . , E. A. Panko

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

[ABRIDGED] We have determined carbon abundances for 51 dwarf stars and manganese abundances for 95 dwarf stars in two distinct and well defined stellar populations - the Galactic thin and thick disks. As these two populations have different…

Astrophysics · Physics 2009-04-14 Thomas Bensby , Sofia Feltzing

Over the last decade a series of results have lent support to the hypothesis of the existence of a long thin bar in the Milky Way with a half-length of 4.5 kpc and a position angle of around 45 deg. This is apparently a very different…

We present a kinematic analysis of a sample of 23,908 G- and K-type dwarfs in the Galactic disk. Based on the $\alpha$-abundance ratio, [$\alpha$/Fe], we separated our sample into low-$\alpha$ thin-disk and high-$\alpha$ thick-disk stars.…

Astrophysics of Galaxies · Physics 2020-06-17 Doo Ri Han , Young Sun Lee , Young Kwang Kim , Timothy C. Beers

Using a semi-analytical model of the evolution of the Milky Way, we show how secular evolution can create distinct overdensities in the phase space of various properties (e.g. age vs metallicity or abundance ratios vs age) corresponding to…

We present a brief summary of our current results on the stellar distribution and population gradients of the resolved stars in the surroundings of ~50 nearby disk galaxies, observed with space- (Hubble & Spitzer) and ground-based…

In this paper, we present low resolution (R=500) near-infrared spectra for selected and serendipitous sources in six inner in-plane Galactic fields, with the aim of analysing the stellar content present. From the equivalent widths of the…

Astrophysics · Physics 2009-11-13 C. González-Fernández , A. Cabrera-Lavers , P. L. Hammersley , F. Garzón

We aim to quantify the chemical and kinematical properties of the Galactic disks with a sample of 119,558 giant stars having abundances and 3D velocities taken or derived from the APOGEE DR17 and Gaia EDR3 catalogs. The Gaussian Mixture…

Astrophysics of Galaxies · Physics 2022-04-20 Guozhen Hu , Zhengyi Shao

We used red clump stars to measure the surface mass density of the Galactic disk in the solar neighbourhood. High resolution spectra of red clump stars towards the NGP have been obtained with the ELODIE spectrograph at OHP for Tycho-2…

Astrophysics · Physics 2009-11-11 O. Bienaymé , C. Soubiran , T. V. Mishenina , V. V. Kovtyukh , A. Siebert

This paper presents the chemical abundance analysis of a sample of 27 red giant stars located in 4 popolous intermediate-age globular clusters in the Large Magellanic Cloud, namely NGC 1651, 1783, 1978 and 2173. This analysis is based on…

Astrophysics · Physics 2009-11-13 A. Mucciarelli , E. Carretta , L. Origlia , F. R. Ferraro

The kinematical properties of the Galactic Thick Disk are studied using absolute proper motions from the SPM3 Catalog and 2MASS near-infrared photometry for a sample of ~1200 red giants in the direction of the South Galactic Pole. The…

We present a model for the [alpha/Fe]-[Fe/H] distribution of stars in the inner Galaxy, R=3-5 kpc, measured as a function of vertical distance |z| from the midplane by Hayden et al. (2015, H15). Motivated by an "upside-down" scenario for…

Astrophysics of Galaxies · Physics 2017-11-01 Jenna K. C. Freudenburg , David H. Weinberg , Michael R. Hayden , Jon A. Holtzman

... 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

This contribution presents an overview of the evolution of Li abundances in stars of the Galactic thin and thick discs, from the observational point of view. The focus is on Li abundances obtained by recent projects and surveys. To separate…

Solar and Stellar Astrophysics · Physics 2020-06-23 Rodolfo Smiljanic

We present the results of an analysis of Pan-STARRS1 Medium Deep Survey multi-band (g,r,i,z,y) images of a sample of 698 low-redshift disk galaxies that span broad ranges in stellar mass, star-formation rate, and bulge/disk ratio. We use…

Thick disks appear to be common in external large spiral galaxies and our own Milky Way also hosts one. The existence of a thick disk is possibly directly linked to the formation history of the host galaxy and if its properties is known it…

Astrophysics of Galaxies · Physics 2015-06-17 Thomas Bensby

We have re-estimated the surface density of the Galactic disk in the solar neighborhood within $\pm$ 0.4 kpc of the Sun using parallaxes and proper motions of a kinematically and spatially unbiased sample of 1476 old bright red giant stars…

Astrophysics · Physics 2009-11-10 V. I. Korchagin , T. M. Girard , T. V. Borkova , D. I. Dinescu , W. F. van Altena