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Related papers: Two-Component Galactic Bulge Probed with Renewed G…

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In this paper, we aim to derive high-precision alpha-element abundances using CRIRES high-resolution IR spectra of 72 cool M giants of the inner Galactic bulge. Silicon, magnesium, and calcium abundances were determined by fitting a…

Astrophysics of Galaxies · Physics 2023-03-08 N. Nieuwmunster , G. Nandakumar , E. Spitoni , N. Ryde , M. Schultheis , R. M. Rich , P. S. Barklem , O. Agertz , F. Renaud , F. Matteucci

... 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

While the number of stars in the Galactic bulge with detailed chemical abundance measurements is increasingly rapidly, the inner Galactic bulge ( |b| < 2$^\circ$) remains poorly studied, due to heavy interstellar absorption and photometric…

Astrophysics of Galaxies · Physics 2018-05-23 G. Nandakumar , N. Ryde , M. Schultheis , B. Thorsbro , H. Jönsson , P. S. Barklem , R. M. Rich , F. Fragkoudi

Recent spectroscopic surveys of the Galactic bulge have unambiguously shown that the bulge contains two main components, that are best separated in their iron content, but also differ in spatial distribution, kinematics, and abundance…

Astrophysics of Galaxies · Physics 2018-10-24 M. Zoccali , E. Valenti , O. A. Gonzalez

The Galactic bulge has a bimodal metallicity distribution function: different kinematic, spatial, and, potentially, age distributions characterize the metal-poor and metal-rich components. Despite this observed dichotomy, which argues for…

Astrophysics of Galaxies · Physics 2019-05-07 A. Rojas-Arriagada , M. Zoccali , M. Schultheis , A. Recio-Blanco , G. Zasowski , D. Minniti , H. Jönsson , R. E. Cohen

We selected Bulge stars from APOGEE DR17 cross-matched with astrometric data from \textit{Gaia} DR3. Bulge stars were divided into sub-samples with line-of-sight velocity dispersion analyzed and the peaks of MDF were detected by both…

Astrophysics of Galaxies · Physics 2025-10-29 Haoyang Liu , Cuihua Du , Zhongcheng Li , Jian Zhang , Mingji Deng

Observations of the stellar content of the Milky Way's bulge helps to understand the stellar content and evolution of distant galaxies. In this brief overview I will first highlight some recent work directed towards measuring the history of…

Astrophysics · Physics 2007-05-23 Jay A. Frogel

We study the evolution of nitrogen in the Galactic halo, thick disc, thin disc and bulge by comparing detailed chemical evolution models with recent observations. The models used in this work have already been constrained to explain the…

Astrophysics of Galaxies · Physics 2021-09-22 Valeria Grisoni , Francesca Matteucci , Donatella Romano

Adopting a single-zone framework, with accretion of primordial gas on a free-fall timescale, the chemical evolution of the Galactic bulge is calculated, assuming (i) a corresponding rapid timescale for star formation, and (ii) an initial…

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

Thin and Thick disk metallicities overlap, but alpha(Fe) relations differ; there is also a hiatus in time before the first thin-disk stars, with a minimum metallicity [Fe/H] = -0.6. Thus there are two `G-dwarf' problems. We fit metallicity…

Astrophysics · Physics 2016-11-03 B. E. J. Pagel

We study the enrichment histories for nine elements, C, four alpha-elements of Mg, Si, Ca, and Ti, Sc, and three iron-peak elements of Co, Ni, and Zn, by using a large number of stellar data, collected by the Stellar Abundances for Galactic…

Astrophysics of Galaxies · Physics 2015-06-17 Shimako Yamada , Takuma Suda , Yutaka Komiya , Wako Aoki , Masayuki Y. Fujimoto

Using the DR12 public release of APOGEE data, we show that thin and thick disk separate very well in the space defined by [$\alpha$/Fe], [Fe/H] and [C/N]. Thick disk giants have both higher [C/N] and higher [$\alpha$/Fe] than do thin disk…

Solar and Stellar Astrophysics · Physics 2015-09-03 T. Masseron , G. Gilmore

We aim at reproducing the chemical evolution of the bulge of M31 by means of a detailed chemical evolution model, including radial gas flows coming from the disk. We study the impact of the initial mass function, the star formation rate and…

Astrophysics of Galaxies · Physics 2015-06-23 M. M. Marcon-Uchida , F. Matteucci , G. A. Lanfranchi , E. Spitoni , V. Grieco

CONTEXT: [ABRIDGED]. For the Milky Way bulge, there are currently essentially no measurements of carbon in un-evolved stars, hampering our abilities to properly compare Galactic chemical evolution models to observational data for this still…

Astrophysics of Galaxies · Physics 2021-12-01 T. Bensby , A. Gould , M. Asplund , S. Feltzing , J. Meléndez , J. A. Johnson , S. Lucatello , A. Udalski , J. C. Yee

We update the treatment of chemical evolution in the Munich semi-analytic model, L-GALAXIES. Our new implementation includes delayed enrichment from stellar winds, supernovae type II (SNe-II) and supernovae type Ia (SNe-Ia), as well as…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Robert M. Yates , Bruno Henriques , Peter A. Thomas , Guinevere Kauffmann , Jonas Johansson , Simon D. M. White

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

Aims. The aim of this work is the study of abundances of the heavy elements Ba, La, Ce, Nd, and Eu in 56 bulge giants (red giant branch and red clump) with metallicities ranging from -1.3 dex to 0.5 dex. Methods. We obtained high-resolution…

Astrophysics of Galaxies · Physics 2016-01-20 M. Van der Swaelmen , B. Barbuy , V. Hill , M. Zoccali , D. Minniti , S. Ortolani , A. Gomez

We report detailed chemical abundance analysis of 27 RGB stars towards the Galactic bulge in Baade's Window for elements produced by massive stars: O, Na, Mg, Al, Si, Ca and Ti. All of these elements are overabundant in the bulge relative…

Astrophysics · Physics 2011-02-11 Jon. P. Fulbright , Andrew McWilliam , R. Michael Rich

We present radial velocities and chemical abundances of O, Na, Mg, Al, Si, Ca, Cr, Fe, Co, Ni, and Cu for a sample of 156 red giant branch stars in two Galactic bulge fields centered near (l,b)=(+5.25,-3.02) and (0,-12). The (+5.25,-3.02)…

Solar and Stellar Astrophysics · Physics 2015-06-22 Christian I. Johnson , R. Michael Rich , Chiaki Kobayashi , Andrea Kunder , Andreas Koch