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Related papers: M22: A [Fe/H] Abundance Range Revealed

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We present the first high spectral resolution abundance analysis of two newly discovered Galactic globular clusters, namely Mercer 5 and 2MASS GC02 residing in regions of high interstellar reddening in the direction of the Galactic center.…

Solar and Stellar Astrophysics · Physics 2015-06-23 Francisco Penaloza , Peter Pessev , Sergio Vasquez , Jura Borissova , Radostin Kurtev , Manuela Zoccali

The stellar system omega Centauri is well known for the large range in abundance among its member stars. Recent work has indicated that the globular cluster M22 (NGC 6656) also possesses an internal abundance range, albeit substantially…

Solar and Stellar Astrophysics · Physics 2015-05-19 G. S. Da Costa , A. F. Marino

In this letter, the results of our low-resolution spectroscopic survey for identifying the hydrogen-deficient (H-deficient) stars in the red giant sample of the globular cluster Omega Cen are reported. Spectral analyses were carried out on…

Solar and Stellar Astrophysics · Physics 2015-06-22 B. P. Hema , Gajendra Pandey

We discuss oxygen and iron abundance patterns in K and M red-giant members of the Galactic bulge and in the young and massive M-type stars inhabiting the very center of the Milky Way. The abundance results from the different bulge studies…

Astrophysics · Physics 2009-11-13 K. Cunha , V. Smith , K. Sellgren , R. Blum , S. Ramirez , D. Terndrup

We have obtained high-res, high S/N ratio CCD echelle spectra of 10 bright red giants in 3 GCs (47Tuc, NGC6752 and NGC6397) roughly spanning the range of metallicities of the galactic GC system; they reveal no evidence of star to star…

Astrophysics · Physics 2009-07-28 E. Carretta , R. G. Gratton

The [Sr/Ba] and [Y/Ba] scatter observed in some galactic halo stars that are very metal-poor stars and in a few individual stars of the oldest known Milky Way globular cluster NGC 6522,have been interpreted as evidence of early enrichment…

Solar and Stellar Astrophysics · Physics 2015-06-22 B. Barbuy , C. Chiappini , E. Cantelli , E. Depagne , M. Pignatari , R. Hirschi , G. Cescutti , S. Ortolani , V. Hill , M. Zoccali , D. Minniti , M. Trevisan , E. Bica , A. Gómez

We present a new method for the determination of [Fe/H] for globular clusters. This new method is based on moderate resolution (R~1500) near-IR spectroscopy in the K-band of 6 to 10 of the brightest giants in a cluster. Our calibration is…

Astrophysics · Physics 2009-11-06 J. A. Frogel , A. W. Stephens , S. Ramirez , D. L. DePoy

We present abundances of several light, alpha, Fe-peak, and neutron-capture elements for 66 red giant branch (RGB) stars in the Galactic globular cluster Omega Centauri. Our observations lie in the range 12.0<V<13.5 and focus on the…

Solar and Stellar Astrophysics · Physics 2011-02-11 Christian I. Johnson , Catherine A. Pilachowski , R. Michael Rich , Jon P. Fulbright

We present elemental abundances for 855 red giant branch (RGB) stars in the globular cluster Omega Centauri (w Cen) from spectra obtained with the Blanco 4m telescope and Hydra multifiber spectrograph. The sample includes nearly all RGB…

Solar and Stellar Astrophysics · Physics 2015-05-19 Christian I. Johnson , Catherine A. Pilachowski

We have obtained high-resolution, high S/N spectra for six red giants in omega Cen: three belonging to the recently discovered, metal-rich Red Giant Branch (RGB-a, Pancino et al. 2000) and three to the metal intermediate population…

Astrophysics · Physics 2009-10-08 E. Pancino , L. Pasquini , V. Hill , F. R. Ferraro , M. Bellazzini

Fluorine is a fairly good tracer of formation histories of multiple stellar populations in globular clusters as already revealed by several studies. Large variations in fluorine abundance in red giant stars of the globular cluster M22 have…

Solar and Stellar Astrophysics · Physics 2015-06-17 P. de Laverny , A. Recio-Blanco

We perform a comparative study of the ex--situ second--parameter pair globular clusters (GCs) M30 and M92, having similar metallicities but different horizontal branch morphologies. We obtain the similar mean primordial carbon abundances…

Astrophysics of Galaxies · Physics 2025-01-10 Jae-Woo Lee

We present a technique that applies spectral synthesis to medium resolution spectroscopy (MRS, R ~ 6000) in the red (6300 A < lambda < 9100 A) to measure [Fe/H] and [alpha/Fe] of individual red giant stars over a wide metallicity range. We…

Astrophysics · Physics 2008-08-09 Evan N. Kirby , Puragra Guhathakurta , Christopher Sneden

We report new metallicity determinations for 39 red giants in a 220 square arcminute region, 1.8 degrees southwest of the bar of the Large Magellanic Cloud. These abundance measurements are based on spectroscopy of the Ca II infrared…

Astrophysics · Physics 2009-10-31 A. A. Cole , T. A. Smecker-Hane , J. S. Gallagher

We present the chemical analysis of 49 giant stars of the globular cluster NGC 2419, using medium resolution spectra collected with the multi-object spectrograph DEIMOS@Keck. Previous analysis of this cluster revealed a large dispersion in…

Astrophysics of Galaxies · Physics 2015-06-11 A. Mucciarelli , M. Bellazzini , R. Ibata , T. Merle , S. C. Chapman , E. Dalessandro , A. Sollima

Spectroscopic abundance determinations for stars spanning a Hubble time in age are necessary in order to unambiguously determine the evolutionary histories of galaxies. Using FORS1 in Multi-Object Spectroscopy mode on ANTU (UT1) at the…

We present O, Na, and Fe abundances, as well as radial velocities, for 113 red giant branch (RGB) and asymptotic giant branch (AGB) stars in the globular cluster M13. The abundances and velocities are based on spectra obtained with the…

Solar and Stellar Astrophysics · Physics 2015-06-05 Christian I. Johnson , Catherine A. Pilachowski

We report abundance analysis for 30 M giant stars in two inner Galactic bulge fields at (l,b)=(0,-1.75) deg and at (l,b)=(1,-2.65) deg, based on R=25,000 infrared spectroscopy from 1.5-1.8um using NIRSPEC at the Keck II telescope. We find…

Astrophysics of Galaxies · Physics 2015-06-03 R. Michael Rich , Livia Origlia , Elena Valenti

We present a detailed study of the strengths of the calcium triplet absorption lines in the spectra of a large sample of red giant members of the luminous outer Galactic halo globular cluster NGC 5824. The spectra were obtained with the…

Solar and Stellar Astrophysics · Physics 2015-06-18 G. S. Da Costa , E. V. Held , I. Saviane

We have derived Mn abundances for more than 200 stars in 19 globular clusters. In addition, Mn abundance determinations have been made for a comparable number of halo field and disk stars possessing an overlapping range of metallicities and…