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Related papers: Neutron-capture elements in the metal-poor globula…

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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

Stellar mass and metallicity are factors that affect the neutron-capture process. Due to this, the enrichment of the ISM and the abundance of neutron-capture elements vary with time, making them suitable probes for the Galactic chemical…

Astrophysics of Galaxies · Physics 2019-11-06 Rebecca Forsberg , Henrik Jönsson , Nils Ryde , Francesca Matteucci

Recent observations of r-process-enriched metal-poor star abundances reveal a non-uniform abundance pattern for elements $Z\leq47$. Based on non-correlation trends between elemental abundances as a function of Eu-richness in a large sample…

We obtain the chemical abundances of six barium stars and two CH subgiant stars based on the high signal-to-noise ratio and high resolution Echelle spectra. The neutron capture process elements Y, Zr, Ba, La, Eu show obvious overabundance…

Astrophysics · Physics 2009-11-13 G. Q. Liu , Y. C. Liang , L. Deng

We present the homogeneous abundance analysis for a combined sample of 185 giants in the bulge globular cluster (GC) NGC 6388. Our results are used to describe the multiple stellar populations and differences or analogies with bulge field…

Astrophysics of Galaxies · Physics 2023-09-06 Eugenio Carretta , Angela Bragaglia

We present the chemical abundances of Fe, alpha- and neutron-capture elements in 12 metal-poor Small Magellanic Cloud (SMC) giant stars, observed with the high-resolution spectrographs UVES/VLT and MIKE/Magellan. These stars have [Fe/H]…

Our aim is to measure accurate, homogeneous neutron-capture element abundances for the sample of 32 EMP giant stars studied earlier in this series, including 22 stars with [Fe/H] $< -$3.0. Based on high-resolution, high S/N spectra from the…

We present new abundance determinations of neutron-capture elements Ge, Zr, Os, Ir, and Pt in a sample of 11 metal-poor (-3.1 <= [Fe/H] <= -1.6) Galactic halo giant stars, based on Hubble Space Telescope UV and Keck I optical…

The enrichment history of heavy neutron-capture elements in the Milky Way disc provides fundamental information about the chemical evolution of our Galaxy and about the stellar sources that made those elements. In this work we give new…

Astrophysics of Galaxies · Physics 2019-02-13 T. Mishenina , M. Pignatari , T. Gorbaneva , S. Bisterzo , C. Travaglio , F. K. Thielemann , C. Soubiran

Analysis of HST STIS ultraviolet spectra of two hot extreme helium stars (EHes): V1920 Cyg and HD 124448 provide the first measurements of abundances of neutron-capture elements for EHes. Although the two stars have similar abundances for…

Astrophysics · Physics 2009-11-10 Gajendra Pandey , David L. Lambert , N. Kameswara Rao , C. Simon Jeffery

The chemical abundances of the very metal-poor double-enhanced stars are excellent information for setting new constraints on models of neutron-capture processes at low metallicity. These stars are known as s+r stars, since they show…

Astrophysics · Physics 2009-11-11 Bo Zhang , Kun Ma , Guide Zhou

We have determined Al, $\alpha$, Fe-peak, and neutron capture elemental abundances for five red giant branch (RGB) stars in the Galactic globular cluster M10. Abundances were determined using equivalent width analyses of moderate resolution…

We describe images of the center of the dense globular cluster M15 (NGC 7078) obtained with the Hubble Space Telescope Wide Field and Planetary Camera 2 (WFPC2). Data taken in the F336W, F439W, and F555W filters (approximately U, B, and V)…

Astrophysics · Physics 2009-10-28 Puragra Guhathakurta , Brian Yanny , Donald P. Schneider , John N. Bahcall

HD 140283 is a nearby (V=7.7) subgiant metal-poor star, extensively analysed in the literature. Although many spectra have been obtained for this star, none showed a signal-to-noise (S/N) ratio high enough to enable a very accurate…

Solar and Stellar Astrophysics · Physics 2012-11-06 C. Siqueira Mello , B. Barbuy , M. Spite , F. Spite

Neutron(n)-capture elements (atomic number Z>30), which can be produced in planetary nebula (PN) progenitor stars via s-process nucleosynthesis, have been detected in nearly 100 PNe. This demonstrates that nebular spectroscopy is a…

Solar and Stellar Astrophysics · Physics 2015-05-30 N. C. Sterling , M. C. Witthoeft , D. A. Esteves , P. C. Stancil , A. L. D. Kilcoyne , R. C. Bilodeau , A. Aguilar

Neutron(n)-capture elements are produced by s-process nucleosynthesis in low- and intermediate-mass AGB stars, and therefore can be enriched in planetary nebulae (PNe). In the last ten years, n-capture elements have been detected in more…

Solar and Stellar Astrophysics · Physics 2017-11-15 N. C. Sterling

We present the distributions of elemental abundance ratios using chemodynamical simulations which include four different neutron capture processes: magneto-rotational supernovae, neutron star mergers, neutrino driven winds, and electron…

Astrophysics of Galaxies · Physics 2018-12-19 Christopher Haynes , Chiaki Kobayashi

In this study we investigate the chemical enrichment of the rapid neutron-capture process in the Small Magellanic Cloud (SMC). We measure [Eu/Fe] abundance ratios in 209 giant stars that are confirmed members of the SMC, providing the first…

Astrophysics of Galaxies · Physics 2025-11-13 Samuele Anoardo , Alessio Mucciarelli , Marco Palla , Lorenzo Santarelli , Carmela Lardo , Donatella Romano

We have obtained high-resolution spectra of 32 giants in the open cluster NGC 7789 using the Wisconsin-Indiana-Yale-NOAO Hydra spectrograph. We explore differences in atmospheric parameters and elemental abundances caused by the use of the…

We investigate the enrichment in elements produced by the slow neutron-capture process ($s$-process) in the globular clusters M4 (NGC 6121) and M22 (NGC 6656). Stars in M4 have homogeneous abundances of Fe and neutron-capture elements, but…

Solar and Stellar Astrophysics · Physics 2014-10-13 Luke J. Shingles , Amanda I. Karakas , Raphael Hirschi , Cherie K. Fishlock , David Yong , Gary S. Da Costa , Anna F. Marino