English
Related papers

Related papers: Complexity on Small Scales III: Iron and alpha Ele…

200 papers

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…

We have derived element abundances in 310 emission-line galaxies from the Early Data Release of the Sloan Digital Sky Survey (SDSS) for which the [O {\sc iii}] 4363 emission line was detected, allowing abundance determination by direct…

Astrophysics · Physics 2009-11-10 Y. I. Izotov , G. Stasinska , N. G. Guseva , T. X. Thuan

Large numbers of low-to-medium resolution spectra of M-type dwarf stars from both the local Galactic disk and halo are available from various surveys. In order to fully exploit these data, we develop a template-fit method using a set of…

Solar and Stellar Astrophysics · Physics 2020-03-11 Neda Hejazi , Sebastien Lepine , Derek Homeier , R. Michael Rich , Michael M. Shara

We present a detailed abundance analysis of 8 stars selected as extremely metal poor candidates from the Hamburg/ESO Survey (HES). For comparison, we have also analysed 3 extremely metal-poor candidates from the HK survey, and 3 additional…

We outline the results of a study of the chemical composition of 14 stars in the Sagittarius dwarf spheroidal galaxy (Sgr dSph). For the Sgr dSph stars with [Fe/H]>-1 the abundances are highly unusual, showing a striking enhancement in…

Astrophysics · Physics 2007-05-23 Andrew McWilliam , Tammy A. Smecker-Hane

The recent introduction of high resolution/large spectral range spectrographs provided the opportunity to investigate in detail the chemical composition of classical Cepheids. This paper is focussed on new abundance determinations for iron…

Astrophysics · Physics 2009-11-13 B. Lemasle , P. Francois , G. Bono , M. Mottini , F. Primas , M. Romaniello

Spectral data on early type galaxies is analyzed for chemical abundance with an emphasis on obtaining detailed abundances for the elements O and Si in addition to C, N, Na, Mg, Ca, Fe, and Ba. The abundance trends with velocity dispersion…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Guy Worthey , Baitian Tang , Jedidiah Serven

We present the first models allowing one to explore in a consistent way the influence of changes in the alpha-element-to-iron abundance ratio on the high-resolution spectral properties of evolving stellar populations. The models cover the…

Astrophysics · Physics 2008-01-08 P. Coelho , G. Bruzual , S. Charlot , A. Weiss , B. Barbuy , J. Ferguson

We have observed ten red giant stars in four old Large Magellanic Cloud globular clusters with the high-resolution spectrograph MIKE on the Magellan Landon Clay 6.5-m telescope. The stars in our sample have up to 20 elemental abundance…

Astrophysics · Physics 2009-11-13 Jennifer A. Johnson , Inese I. Ivans , Peter B. Stetson

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

We present abundances of carbon and oxygen as well as abundance ratios 12C/13C for a sample of carbon stars in the LMC, SMC, Carina, Sculptor and Fornax dwarf galaxies. The overall metallicities in these dwarf galaxies are lower than in the…

Astrophysics · Physics 2007-05-23 R. Wahlin , K. Eriksson , B. Gustafsson , K. H. Hinkle , D. L. Lambert , N. Ryde , B. Westerlund

We present radial velocities, Fe, and Al abundances for 180 red giant branch (RGB) stars in the Galactic globular cluster Omega Centauri ($\omega$ Cen). The majority of our data lie in the range 11.0$<$V$<$13.5, which covers the RGB from…

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

We report on detailed abundances of giants in the Galactic bulge, measured with the HIRES echelle spectrograph on the 10-m Keck telescope. We also review other work on the bulge field population and globular clusters using Keck/HIRES. Our…

Astrophysics · Physics 2015-06-24 R. M. Rich , A. McWilliam

We present new observations of copper and zinc abundances in 90 metal-poor stars, belonging to the metallicity range -3< [Fe/H] < -0.5. The present study is based on high resolution spectroscopic measurements collected at the Haute Provence…

Astrophysics · Physics 2009-11-07 T. V. Mishenina , V. V. Kovtyukh , C. Soubiran , C. Travaglio , M. Busso

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

We present the first in a series of papers studying the X-ray properties of 28 early type galaxies spanning ~3 orders of magnitude in L_x. We report emission-weighted constraints for Fe, O, Ne, Mg, Si, S and Ni. We find no evidence of the…

Astrophysics · Physics 2009-11-10 Philip J. Humphrey , David A. Buote

We carried out a homogeneous abundance study for various elements, including $\alpha$-elements, iron peak elements and $n$-capture elements for 35 metal-poor stars with a wide metallicity range ($-3.0\lesssim$[Fe/H]$\lesssim-0.5$).…

Astrophysics · Physics 2008-06-02 Jeong-Deok Lee , Sang-Gak Lee , Kang-Min Kim

We measure chemical abundance ratios and radial velocities in four massive (i.e., young) [alpha/Fe]-rich red giant stars using high-resolution high-S/N spectra from ESPaDOnS fed by Gemini-GRACES. Our differential analysis ensures that our…

We present a Magellan/MIKE high-resolution (R ~ 35,000) spectrum of the ancient star SD 1313-0019 which has an iron abundance of [Fe/H] = -5.0, paired with a carbon enhancement of [C/Fe] ~ 3.0. The star was initially identified by Allende…

Solar and Stellar Astrophysics · Physics 2015-09-23 Anna Frebel , Anirudh Chiti , Alexander P. Ji , Heather R. Jacobson , Vinicius M. Placco