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Related papers: Composition of the Galactic bulge

200 papers

We compute the chemical evolution of the Galactic bulge in the context of an inside-out model for the formation of the Milky Way. The model contains updated stellar yields from massive stars. The main purpose of the paper is to compare the…

Astrophysics · Physics 2009-11-13 Silvia K. Ballero , Francesca Matteucci , Livia Origlia , R. Michael Rich

Fluorine (19F) abundances are derived in a sample of 6 bulge red giants in Baade's Window. These giants span a factor of 10 in metallicity and this is the first study to define the behavior of 19F with metallicity in the bulge. The bulge…

Astrophysics · Physics 2009-11-13 K. Cunha , V. V. Smith , B. K. Gibson

Determining elemental abundances of bulge stars can, via chemical evolution modeling, help to understand the formation and evolution of the bulge. Recently there have been claims both for and against the bulge having a different…

Astrophysics of Galaxies · Physics 2017-02-08 H. Jönsson , N. Ryde , M. Schultheis , M. Zoccali

We present an abundance analysis based on high dispersion and high signal-to-noise ratio Keck spectra of a very highly microlensed Galactic bulge dwarf, OGLE-2007-BLG-349S, with Teff ~ 5400 K. The amplification at the time the spectra were…

Astrophysics · Physics 2009-11-13 Judith G. Cohen , Wenjin Huang , A. Udalski , Andrew Gould , Jennifer Johnson

Context. The measurement of $\alpha$-elements abundances provides a powerful tool to put constraints on chemical evolution and star formation history of galaxies. The majority of studies on the $\alpha$-element Sulfur (S) are focused on…

Astrophysics of Galaxies · Physics 2021-12-22 F. Lucertini , L. Monaco , E. Caffau , P. Bonifacio , A. Mucciarelli

This work explores the detailed chemistry of the Milky Way bulge using the HERMES spectrograph on the Anglo-Australian Telescope. Here we present the abundance ratios of 13 elements for 832 red giant branch and clump stars along the minor…

Astrophysics of Galaxies · Physics 2019-05-08 L. Duong , M. Asplund , D. M. Nataf , K. C. Freeman , M. Ness

We report chemical abundances of Na, Al, Zr, La, Nd, and Eu for 39 red giant branch (RGB) stars and 23 potential inner disk red clump stars located in Plaut-s low extinction window. We also measure lithium for a super Li-rich RGB star. The…

Solar and Stellar Astrophysics · Physics 2015-06-04 Christian I. Johnson , R. Michael Rich , Chiaki Kobayashi , Jon P. Fulbright

Lithium abundances are presented for 91 dwarf and subgiant stars in the Galactic bulge. The analysis is based on line synthesis of the 7Li line at 6707 {\AA} in high-resolution spectra obtained during gravitational microlensing events, when…

Astrophysics of Galaxies · Physics 2020-02-26 T. Bensby , S. Feltzing , J. C. Yee , J. A. Johnson , A. Gould , M. Asplund , J. Meléndez , S. Lucatello

We show that the Galactic bulge and disk share a similar, strong, decline in [O/Mg] ratio with [Mg/H]. The similarity of the [O/Mg] trend in these two, markedly different, populations suggests a metallicity-dependent modulation of the…

Astrophysics · Physics 2009-11-13 A. McWilliam , F. Matteucci , S. Ballero , R. M. Rich , J. P. Fulbright , G. Cescutti

We present chemical abundances in K and M red-giant members of the Galactic bulge derived from high-resolution infrared spectra obtained with the Phoenix spectrograph on Gemini-South. The elements studied are carbon, nitrogen, oxygen,…

Astrophysics · Physics 2008-11-26 Katia Cunha , Verne V. Smith

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

The atmospheric parameters and abundances of Mg, Si, Ca, and Ti have been determined for 20 stars using the Gaia DR2 parallaxes, high-resolution spectra, and the non-local thermodynamic equilibrium (non-LTE) line formation modeling. A…

Solar and Stellar Astrophysics · Physics 2019-09-04 Lyudmila Mashonkina , Maria Neretina , Tatyana Sitnova , Yuri Pakhomov

We analyze a high-resolution spectrum of a microlensed G-dwarf in the Galactic bulge, acquired when the star was magnified by a factor of 110. We measure a spectroscopic temperature, derived from the wings of the Balmer lines, that is the…

Astrophysics · Physics 2009-11-13 Jennifer A. Johnson , B. Scott Gaudi , Takahiro Sumi , Ian A. Bond , Andrew Gould

Oxygen and zinc in the Galactic bulge are key elements for the understanding of the bulge chemical evolution. Oxygen-to-iron abundance ratios provide a most robust indicator of the star formation rate and chemical evolution of the bulge.…

Solar and Stellar Astrophysics · Physics 2018-07-18 C. R. da Silveira , B. Barbuy , A. C. S. Friaça , V. Hill , M. Zoccali , M. Rafelski , O. A. Gonzalez , D. Minniti , A. Renzini , S. Ortolani

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

AIMS: We spectroscopically characterize the Galactic Bulge to infer its star formation timescale, compared to the other Galactic components, through the chemical signature on its individual stars. METHODS: We derived iron and oxygen…

Astrophysics · Physics 2010-01-07 M. Zoccali , A. Lecureur , B. Barbuy , V. Hill , A. Renzini , D. Minniti , Y. Momany , A. Gomez , S. Ortolani

High resolution (R$\sim$22,500) spectra for 400 red clump giants, in four fields within $\rm -4.8^{\circ} \lesssim b \lesssim -3.4^{\circ}$ and $\rm -10^{\circ} \lesssim l \lesssim +10^{\circ}$, were obtained within the GIRAFFE Inner Bulge…

AIMS. Our aims are twofold. First we aim to evaluate the robustness and accuracy of stellar parameters and detailed elemental abundances that can be derived from high-resolution spectroscopic observations of microlensed dwarf and subgiant…

Astrophysics of Galaxies · Physics 2015-05-13 T. Bensby , J. A. Johnson , J. Cohen , S. Feltzing , A. Udalski , A. Gould , W. Huang , I. Thompson , J. Simmerer , D. Adén

We present abundance analyses based on high dispersion and high signal-to-noise ratio Magellan spectra of two highly microlensed Galactic bulge stars in the region of the main sequence turnoff with Teff ~ 5650 K. We find that…

Solar and Stellar Astrophysics · Physics 2009-06-25 Judith G. Cohen , Ian B. Thompson , Takahiro Sumi , Ian Bond , Andrew Gould , Jennifer A. Johnson , Wenjin Huang , Greg Burley

We report the first abundance analysis of 17 M giant stars in the inner Galactic bulge at $(l,b)=(0\deg,-1\deg)$, based on $R=25,000$ infrared spectroscopy $(1.5-1.8 ~\mu \rm m)$ using NIRSPEC at the Keck telescope. Based on their…

Astrophysics · Physics 2009-11-13 R. Michael Rich , Livia Origlia , Elena Valenti