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Related papers: Heavy elements and chemical enrichment in globular…

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We have carried out a detailed abundance analysis for 21 elements in a sample of 25 stars with a wide range in luminosity from luminous giants to stars near the main sequence turnoff in the globular cluster M13 and in a sample of 13 stars…

Astrophysics · Physics 2009-10-12 Judith G. Cohen , Jorge Melendez

This research forms part of an investigation into heavy element abundances in Asymptotic Giant Branch (AGB) stars in various stellar environments. Seven giant stars in the southern globular cluster 47 Tuc have been observed using the…

Astrophysics · Physics 2008-11-26 E. C. Wylie , P. L. Cottrell , C. A. Sneden , J. C. Lattanzio

We present the abundances of 23 elements, including 11 heavy elements (Cu, Zn, Sr, Y, Zr, Ba, La, Ce, Nd, Sm, Eu) for up to 86 metal-poor (-2 < [Fe/H] < -1) subgiants. We use KORG, a state of the art spectral synthesis package, to derive…

Solar and Stellar Astrophysics · Physics 2025-12-03 Emily J. Griffith , Marissa Blum , David H. Weinberg , Jennifer A. Johnson , Tawny Sit , Ilya Ilyin , Klaus G. Strassmeier

We present the LTE abundance analysis of high resolution spectra for red giant stars in the peculiar bulge globular cluster NGC 6388. Spectra of seven members were taken using the UVES spectrograph at the ESO VLT2 and the multiobject FLAMES…

We have observed high-dispersion echelle spectra of red giant members in the five open clusters NGC 1342, NGC 1662, NGC 1912, NGC 2354 and NGC 2447 and determined their radial velocities and chemical compositions. These are the first…

Solar and Stellar Astrophysics · Physics 2015-06-17 Arumalla B. S. Reddy , Sunetra Giridhar , David L. Lambert

In this paper we refine our method for the abundance analysis of high resolution spectroscopy of the integrated light of unresolved globular clusters (GCs). This method was previously demonstrated for the analysis of old ($>$10 Gyr) Milky…

Astrophysics of Galaxies · Physics 2015-05-27 J. E. Colucci , R. A. Bernstein , S. A. Cameron , A. McWilliam

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 report the abundance analysis of one red giant branch star in the metal-poor outer halo globular cluster NGC 5694. We obtain [Fe/H] = -1.93, based on the ionized lines, and our metallicity measurement is in good agreement with previous…

Astrophysics · Physics 2009-11-11 Jae-Woo Lee , Mercedes Lopez-Morales , Bruce W. Carney

The aim of this work is to determine abundances of neutron-capture elements for thin- and thick-disc F, G, and K stars in several sky fields near the north ecliptic pole and to compare the results with the Galactic chemical evolution…

Abundances for Fe, O, and the alpha-elements (Mg, Si, Ca, and Ti) have been derived from high resolution spectra of a sample of about one hundred dwarfs with high precision parallaxes measured by HIPPARCOS. The stars have metal abundances…

Astrophysics · Physics 2007-05-23 R. G. Gratton , E. Carretta , G. Clementini , C. Sneden

We present a strictly line-by-line differential analysis of a moderately $r$-process-enhanced star ($r$-I: HD~107752) with respect to a strongly $r$-process-enhanced star ($r$-II: CS~31082-0001) to investigate the possible common origin of…

The formation of sdBs is still puzzling, as is the chemical composition of their atmospheres. While helium and other light elements are depleted relative to solar values, heavy elements are highly enriched. Diffusion processes in the hot,…

Astrophysics · Physics 2008-04-09 S. Geier , U. Heber , R. Napiwotzki

We present a study of accurate stellar parameters and iron abundances for 39 giants and 16 dwarfs in the 13 open clusters IC2714, IC4651, IC4756, NGC2360, NGC2423, NGC2447 (M93), NGC2539, NGC2682 (M67), NGC3114, NGC3680, NGC4349, NGC5822,…

Astrophysics · Physics 2009-11-13 N. C. Santos , C. Lovis , G. Pace , J. Melendez , D. Naef

With the exception of Terzan 5, all the Galactic globular clusters that possess significant metallicity spreads, such as omega Cen and M22, are preferentially the more luminous clusters with extended horizontal branches. Here we present…

Detailed chemical composition studies of stars with enhanced abundances of neutron-capture elements can provide observational constraints for neutron-capture nucleosynthesis studies and clues for understanding their contribution to the…

Solar and Stellar Astrophysics · Physics 2016-08-31 Upakul Mahanta , Drisya Karinkuzhi , Aruna Goswami , Kalpana Duorah

Context. Open clusters are ideal test particles to study the chemical evolution of the Galactic disc. However the existing high-resolution abundance determinations, not only of [Fe/H], but also of other key elements, is largely insufficient…

Astrophysics of Galaxies · Physics 2015-05-28 R. Carrera , E. Pancino

Based on high-resolution spectra obtained with Magellan/MIKE, we present a chemo-dynamical analysis for 27 near main-sequence turnoff metal-poor stars, including 20 stars analyzed for the first time. The sample spans a range in [Fe/H] from…

Astrophysics of Galaxies · Physics 2023-05-10 Mohammad K. Mardini , Anna Frebel , Leyatt Betre , Heather Jacobson , John E. Norris , Norbert Christlieb

Almost several decades after the discovery of the first multiple populations in galactic globular clusters (GC) the debate on their formation is still extremely current and NGC2808 remains one of the best benchmark to test any scenario for…

Solar and Stellar Astrophysics · Physics 2018-07-18 Marcella Di Criscienzo , Paolo Ventura , Francesca D'Antona , Flavia Dell'Agli , Marco Tailo

Globular clusters (GCs) are spheroidal concentrations typically containing of the order of 10^5 to 10^6, predominantly old, stars. Historically, they have been considered as the closest counterparts of the idealized concept of "simple…

Solar and Stellar Astrophysics · Physics 2015-05-14 A. A. R. Valcarce , M. Catelan

Using the 2dF multi-fibre instrument on the AAT, moderate resolution spectra have been obtained for a large sample of stars on the main sequence and at the turnoff in the unusual globular cluster omega Centauri. We investigate the behaviour…

Astrophysics · Physics 2009-11-11 G. S. Da Costa , Laura Stanford , John E. Norris , R. D. Cannon