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Related papers: The Evolution of Copper in the Globular Cluster Om…

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We propose a new chemical evolution model aimed at explaining the chemical properties of globular clusters (GC) stars. Our model depends upon the existence of (i) a peculiar pre-enrichment phase in the GC's parent galaxy associated with…

Astrophysics of Galaxies · Physics 2009-11-13 Andrea Marcolini , Brad K. Gibson , Amanda I. Karakas , Patricia Sanchez-Blazquez

The Milky Way bulge is an important tracer of the early formation and chemical enrichment of the Galaxy. The abundances of different iron-peak elements in field bulge stars can give information on the nucleosynthesis processes that took…

Solar and Stellar Astrophysics · Physics 2020-08-19 H. Ernandes , B. Barbuy , A. Friaça , V. Hill , M. Zoccali , D. Minniti , A. Renzini , S. Ortolani

The Hubble Space Telescope has been used to obtain WFPC2 (V,I) photometry for a sample of 10,000 red giant stars in the outer halo of the giant elliptical NGC 5128. Comparison with the fiducial RGBs of Milky Way globular clusters and model…

Astrophysics · Physics 2009-10-31 G. L. H. Harris , W. E. Harris , G. B. Poole

Elemental abundances of carbon, nitrogen, oxygen, magnesium, aluminum, and silicon are presented for a sample of twelve rapidly rotating OB star (v sin i > 60 km s^-1) members of the Cep OB2, Cyg OB3 and Cyg OB7 associations. The abundances…

Astrophysics · Physics 2009-11-07 Simone Daflon , Katia Cunha , Keith Butler , Verne V. Smith

We present age estimates for over 8100 sub-giant branch (SGB) stars in Omega Centauri ($\omega$ Cen) to study its star formation history. Our large data set, which combines multi-wavelength HST photometry with MUSE metallicities, provides…

We present new medium-band uvby Stromgren and broad-band VI photometry for the central regions of the globular cluster Omega Cen. From this photometry we have obtained differential reddening estimates relative to two other globular clusters…

We present results of a search for optical counterparts of X-ray sources in and toward the globular cluster Omega Centauri (NGC 5139) using the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope. The ACS data consist of a…

Solar and Stellar Astrophysics · Physics 2015-06-12 Adrienne M. Cool , Daryl Haggard , Tersi Arias , Michelle Brochmann , Jason Dorfman , April Gafford , Vivian White , Jay Anderson

Recent work suggests that galaxy evolution, and the build-up of stellar mass (M*) over cosmic time, is characterized by changes with redshift of star formation rate (SFR) and oxygen abundance (O/H). In a companion paper, we have compiled a…

Astrophysics of Galaxies · Physics 2016-08-31 Leslie Hunt , Pratika Dayal , Laura Magrini , Andrea Ferrara

Historically, photometry has been largely used to identify stellar populations (MPs) in Globular Clusters (GCs) by using diagrams that are based on colours and magnitudes that are mostly sensitive to stars with different metallicities or…

Solar and Stellar Astrophysics · Physics 2020-07-29 A. P. Milone , A. F. Marino , A. Renzini , C. Li , S. Jang , E. P. Lagioia , M. Tailo , G. Cordoni , M. Carlos , E. Dondoglio

We conducted an investigation on the chemical abundances of 4,316 stars in the red giant branch (RGB) phase from the recently released APO-K2 catalogue. Our aim was to characterize the abundance trends of the single elements with…

Astrophysics of Galaxies · Physics 2024-07-09 G. Valle , M. Dell'Omodarme , P. G. Prada Moroni , S. Degl'Innocenti

We present a spectroscopic search for halo field stars that originally formed in globular clusters. Using moderate-resolution SDSS-III/SEGUE-2 spectra of 561 red giants with typical halo metallicities (-1.8 < [Fe/H] < -1.0), we identify 16…

Astrophysics of Galaxies · Physics 2015-05-30 Sarah L. Martell , Jason P. Smolinski , Timothy C. Beers , Eva K. Grebel

We present chemical abundances for O, Na, Mg, Al, Si, Ca, Ti and Fe in eight red giants and one turnoff star in the metal rich globular cluster 47 Tuc, based on spectroscopy with the MIKE high resolution spectrograph on the Magellan 6.5-m…

Astrophysics · Physics 2009-11-13 Andreas Koch , Andrew McWilliam

Sc and Mn abundances are determined for 119 F and G main-sequence stars with -1.4 < [Fe/H] < +0.1, representing stars from the thin disk, the thick disk and the halo. The results indicate that Sc behaves like an alpha-element, showing a…

Astrophysics · Physics 2007-05-23 P. E. Nissen , Y. Q. Chen , W. J. Schuster , G. Zhao

We present a detailed study of the composition of 20 M giants in the Galactic center with 15 of them confirmed to be in the Nuclear Star Cluster. As a control sample we have also observed 7 M giants in the Milky Way Disk with similar…

[ABRIDGED] Metal-rich globular clusters provide important tracers of the formation of our Galaxy. Moreover, and not less important, they are very important calibrators for the derivation of properties of extra-galactic metal-rich stellar…

Astrophysics · Physics 2009-11-13 S. Feltzing , F. Primas , R. A. Johnson

Although globular clusters are generally chemically homogeneous, substantial abundance variations are sometimes seen even among unevolved main sequence stars, especially for the CNO group of elements. Multi-object intermediate-dispersion…

Astrophysics · Physics 2007-05-23 Russell Cannon , Gary Da Costa , John Norris , Laura Stanford , Barry Croke

The results of determining the metallicity, age, helium mass fraction (Y) and abundances of the elements C, N, Mg, Ca, Mn, Ti and Cr by moderate resolution spectra for four globular clusters in the galaxy M 31: Bol 6, Bol 20, Bol 45 and Bol…

Astrophysics of Galaxies · Physics 2022-01-19 M. I. Maricheva

We present a chemical composition analysis of 36 giant stars in the mildly metal-poor globular cluster M5 (NGC 5904). The analysis makes use of high resolution data acquired at the Keck I telescope as well as a re-analysis of high…

The discovery of the Sagittarius dwarf galaxy, which is being tidally disrupted by and merging with the Milky Way, supports the view that the halo of the Galaxy has been built up at least partially by the accretion of similar dwarf systems.…

Studying the abundances in metal-poor globular clusters is crucial for understanding the formation of the Galaxy and the nucleosynthesis processes in the early Universe. We observed 13 red giant stars from the metal-poor globular cluster…

Solar and Stellar Astrophysics · Physics 2025-05-08 Avrajit Bandyopadhyay , Rana Ezzeddine , Vinicius M. Placco , Anna Frebel , David S Aguado , Ian U. Roederer