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Related papers: Individual Alpha Elements, C, N, and Ba in Early T…

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We have derived abundances of O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Fe, Ni and Ba for 43 metal-poor field stars in the solar neighbourhood with iron abundances [Fe/H] ranging from -0.4 to -3.0. Total abundance errors are estimated to about…

We analyse the abundance ratios of the light elements Mg, Ca, C and N, relative to Fe, for 147 red-sequence galaxies in the Coma cluster and the Shapley Supercluster. The sample covers a six-magnitude range in luminosity, from giant…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Russell J. Smith , John R. Lucey , Michael J. Hudson , Terry J. Bridges

CONTEXT:The detailed chemical abundances of extremely metal-poor (EMP) stars are key guides to understanding the early chemical evolution of the Galaxy. Most existing data are, however, for giant stars which may have experienced internal…

Based on a simple, but fairly successful, model of the chemical evolution of the Milky Way disk, we study the evolution of the abundances of the elements He, C, N, O, Ne, Mg, Al, Si, S, Ar and Fe. We use metallicity dependent yields for…

Astrophysics · Physics 2007-05-23 J. L. Hou , N. Prantzos , S. Boissier

Modern spectroscopy of early-type stars often aims at studying complex physical phenomena. Comparatively less attention is paid to identifying and studying the "normal" A- and B-type stars and testing how the basic atomic parameters and…

Solar and Stellar Astrophysics · Physics 2015-05-13 L. Fossati , T. Ryabchikova , S. Bagnulo , E. Alecian , J. Grunhut , O. Kochukhov , G. Wade

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

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

The abundances of the {\it rare} light elements, Li, Be, and B, provide clues about stellar structure and evolution, about Galactic evolution and about their nucleosynthesis, including production during the Big Bang. The abundances of the…

Astrophysics · Physics 2007-05-23 Ann Merchant Boesgaard

Although evidence is accumulating that abundance ratios in galaxies are often non-solar, they are far from understood. I resume the current evidence for non-solar abundance ratios, supplementing the recent review by Worthey (1998) with some…

Astrophysics · Physics 2007-05-23 Reynier Peletier

We discuss chemical enrichments of ~4000 SDSS early-type galaxies using as tracers the element abundance ratios [C/Fe], [N/Fe], [O/Fe], [Mg/Fe], [Ca/Fe] and [Ti/Fe]. We utilise the stellar population models of absorption line indices from…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Jonas Johansson , Daniel Thomas , Claudia Maraston

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

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 present abundance ratios for 23 elements with respect to Fe in a sample of stars with a wide range in luminosity, from luminous giants to stars near the turnoff, in the globular cluster M71. The analyzed spectra, obtained with HIRES at…

Astrophysics · Physics 2009-11-07 Solange V. Ramirez , Judith G. Cohen

We have investigated the poorly-understood origin of nitrogen in the early Galaxy by determining N abundances in 35 extremely metal-poor halo giants (22 stars have [Fe/H]<-3.0) using the C and O abundances determined in Paper V. Because any…

The source of hot gas in elliptical galaxies is thought to be due to stellar mass loss, with contributions from supernova events and possibly from infall from a surrounding environment. This picture predicts supersolar values for the…

High Energy Astrophysical Phenomena · Physics 2011-02-11 Jun Ji , Jimmy A. Irwin , Alex Athey , Joel N. Bregman , Edward J. Lloyd-Davies

We have analyzed ASCA data of 27 early-type galaxies, and studied the properties of their X-ray emitting ISM (Inter Stellar Medium) in detail. We found that overlapping lines and free-bound continuum cause strong coupling in the derived…

Astrophysics · Physics 2015-06-24 Kyoko Matsushita , Takaya Ohashi , Kazuo Makishima

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

We present the iron abundance and abundance ratios for 18 elements with respect to Fe in a sample of stars with a wide range in luminosity from luminous giants to stars near the turnoff in the globular cluster M5. The analyzed spectra,…

Astrophysics · Physics 2009-11-07 Solange V. Ramirez , Judith G. Cohen

We present high-quality ground-based spectroscopic observations of 54 supergiant H II regions in 50 low-metallicity blue compact galaxies with oxygen abundances 12 + log O/H between 7.1 and 8.3. We use the data to determine abundances for…

Astrophysics · Physics 2009-10-31 Y. I. Izotov , T. X. Thuan

The present sample of nearby bulgelike dwarf stars has kinematics and metallicities characteristic of a probable inner disk or bulge origin. Ages derived by using isochrones give 10-11 Gyr for these stars and metallicities are in the range…

Astrophysics · Physics 2009-11-07 Luciana Pompeia , Beatriz Barbuy , Michel Grenon