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Related papers: Composition of the Galactic bulge

200 papers

We present results for the evolution of the abundances of heavy elements (O, Mg, Al, Si, K, Ca, Cr, Mn, Ni and Fe) in the inner Galactic regions ($R_{GC} < 4$kpc). We adopt a detailed chemical evolution model already tested for the Galactic…

Astrophysics of Galaxies · Physics 2020-05-06 F. Matteucci , A. Vasini , V. Grisoni , M. Schultheis

We present the average abundances of the intermediate elements obtained by performing a stacked analysis of all the galaxy clusters in the archive of the X-ray telescope ASCA. We determine the abundances of Fe, Si, S, and Ni as a function…

Astrophysics · Physics 2009-11-10 W. H. Baumgartner , M. Loewenstein , D. J. Horner , R. F. Mushotzky

(Abridged) We reassess the alpha-element abundance ratios (Ne/O, S/O, Ar/O) with respect to metallicity in ~1000 spectra of Galactic and extragalactic HII regions and star-forming galaxies (SFGs) of the local Universe. Using the DEep…

Detailed elemental-abundance patterns of giant stars in the Galactic halo measured by APOGEE-2 have revealed the existence of a unique and significant stellar sub-population of silicon-enhanced ([Si/Fe]$\gtrsim +0.5$) metal-poor stars,…

Astrophysics of Galaxies · Physics 2021-01-04 José G. Fernández-Trincado , Timothy C. Beers , Dante Minniti

We present gas-phase abundances of carbon (C), $\alpha$-elements (O, Ne, Si, and Ar) and iron (Fe) obtained from stacked spectra of high-$z$ star-forming galaxies with the deep Near Infrared Spectrograph medium-resolution data from the…

We present an R=45,000 Keck spectrum of the microlensed Galactic bulge G-dwarf OGLE-2006-BLG-265, which has a high (~60) signal-to-noise ratio despite its short (15 min) exposure time because the source was magnified by A~135. While it is…

Measurements based on a large number of red giant stars suggest a broad metallicity distribution function (MDF) for the Galactic bulge, centered on [Fe/H]=-0.1. However, recently, a new opportunity emerged to utilize temporary flux…

Astrophysics of Galaxies · Physics 2011-02-11 T. Bensby , S. Feltzing , J. A. Johnson , A. Gal-Yam , A. Udalski , A. Gould , C. Han , D. Adén , J. Simmerer

We analyze the relations between the relative magnesium abundances, metallicities, and Galactic orbital elements for halo stars. We show that the relative magnesium abundances in protodisk halo stars are virtually independent of metallicity…

Astrophysics · Physics 2010-11-11 V. A. Marsakov , T. V. Borkova

The galaxy formation process in the $\Lambda$-Cold Dark Matter scenario can be constrained from the analysis of stars in the Milky Way's halo system. We examine the variation of chemical abundances in distant halo stars observed by the…

We analyze a sample of 3,944 low-resolution (R ~ 2000) optical spectra from the Sloan Digital Sky Survey (SDSS), focusing on stars with effective temperatures 5800 < Teff < 6300 K, and distances from the Milky Way plane in excess of 5 kpc,…

We have previously reported on chemical abundance trends with evolutionary state in the globular cluster NGC 6397 discovered in analyses of spectra taken with FLAMES at the VLT. Here, we reinvestigate the FLAMES-UVES sample of 18 stars,…

Solar and Stellar Astrophysics · Physics 2012-09-24 T. Nordlander , A. J. Korn , O. Richard , K. Lind

The presence of two stellar populations in the Milky Way bulge has been reported recently. We aim at studying the abundances and kinematics of stars in the outer bulge, thereby providing additional constraints on models of its formation.…

Astrophysics of Galaxies · Physics 2015-06-05 Stefan Uttenthaler , Mathias Schultheis , David. M. Nataf , Annie C. Robin , Thomas Lebzelter , B. Chen

Baade's window (BW) is one of the most observed Galactic bulge fields in terms of chemical abundances. Due to its low and homogeneous interstellar absorption it is considered as a calibration field for Galactic bulge studies. In the era of…

We determine the iron distribution function (IDF) for bulge field stars, in three different fields along the Galactic minor axis and at latitudes b=-4 deg, b=-6 deg, and b=-12 deg. A fourth field including NGC6553 is also included in the…

Astrophysics · Physics 2011-05-18 M. Zoccali , V. Hill , A. Lecureur , B. Barbuy , A. Renzini , D. Minniti , A. Gomez , S. Ortolani

Recent work has shown that most globular clusters have at least two chemically distinct components, as well as cluster-to-cluster differences in the mean [O/Fe], [Mg/Fe], and [Si/Fe] ratios at similar [Fe/H] values. In order to investigate…

Solar and Stellar Astrophysics · Physics 2015-06-05 Don A. VandenBerg , Peter A. Bergbusch , Aaron Dotter , Jason W. Ferguson , Georges Michaud , Jacques Richer , Charles Proffitt

We report abundance analysis for 6 M giant members of the old open cluster NGC6791, based on infrared spectroscopy (1.5-1.8 micron) at R=25,000, using the NIRSPEC spectrograph at the Keck II telescope. We find the iron abundance <[Fe/H]>=…

Astrophysics · Physics 2009-11-11 L. Origlia , E. Valenti , R. M. Rich , F. R. Ferraro

We derive abundance ratios for nine stars in the relatively high-metallicity bulge globular cluster NGC 6380. We find a mean cluster metallicity between [Fe/H]$= -0.80$ and $-0.73$, with no clear evidence for a variation in iron abundances…

We present Na, Mg and Al abundances in a set of 98 stars with known giant planets, and in a comparison sample of 41 ``single'' stars. The results show that the [X/H] abundances (with X = Na, Mg and Al) are, on average, higher in stars with…

Astrophysics · Physics 2009-11-10 P. Beirao , N. C. Santos , G. Israelian , M. Mayor

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

This paper explores the integrated-light characteristics of the Milky Way (MW) bulge and to what extent they match those of elliptical galaxies in the local universe. We model composite stellar populations with realistic abundance…

Astrophysics of Galaxies · Physics 2015-06-22 Baitian Tang , Guy Worthey , A. Bianca Davis