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Related papers: A Globular Cluster Metallicity Scale Based on the …

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The near-infrared Calcium II Triplet (CaT), around 850nm, is a key metallicity indicator for red giant stars. We present a revised [Fe/H] calibration as a function of CaT line strengths and four luminosity indicators, including the $Gaia$…

Solar and Stellar Astrophysics · Physics 2026-02-04 M. Navabi , R. Carrera , N. E. D. Noël , C. Gallart , E. Pancino , M. De Leo

We present LTE chemical abundances for five red giants and one AGB star in the Galactic globular cluster (GC) M5 based on high resolution spectroscopy using the MIKE spectrograph on the Magellan 6.5-m Clay telescope. Our results are based…

Astrophysics of Galaxies · Physics 2015-05-18 Andreas Koch , Andrew McWilliam

We extend our previous calibration of the infrared Ca II triplet as metallicity indicator to the metal-poor regime by including observations of 55 field stars with [Fe/H] down to -4.0 dex. While we previously solved the saturation at…

Astrophysics of Galaxies · Physics 2015-06-16 R. Carrera , E. Pancino , C. Gallart , A. del Pino

We present spectroscopic abundances and radial velocities for giant stars in the Galactic globular cluster omega Centauri based on the CaII infrared triplet. Two samples of stars were observed: 234 stars at M_V = 1.25 on the lower giant…

Astrophysics · Physics 2009-10-05 Nicholas B. Suntzeff , Robert P. Kraft

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

Globular Clusters (GCs) are now well known to almost universally show multiple popu-lations (MPs). The HST UV Legacy Survey of a large number of Galactic GCs in UV filters optimized to explore MPs finds that a small fraction of GCs, termed…

To provide an empirical calibration relation in order to convert Lick indices into abundances for the integrated light of old, simple stellar populations for a large range in the observed [Fe/H] and [alpha/Fe]. This calibration supersedes…

Astrophysics of Galaxies · Physics 2015-05-27 A. Pipino , I. J. Danziger

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…

Well determined radial velocities and abundances are essential for analyzing the properties of the Globular Cluster system of the Milky Way. However more than 50% of these clusters have no spectroscopic measure of their metallicity. In this…

We present high quality near infrared Color Magnitude Diagrams of 10 Galactic Globular Clusters (GCs) spanning a wide metallicity range (-2.15<[Fe/H]<-0.2). This homogeneous data-base has been used to perform a detailed analysis of the Red…

Astrophysics · Physics 2009-10-31 Francesco R. Ferraro , Paolo Montegriffo , Livia Origlia , Flavio Fusi Pecci

Context. Globular clusters are considered key objects for understanding the formation and evolution of the Milky Way. In this sense, their characterisation in terms of their chemical and orbital parameters can provide constraints to the…

Astrophysics of Galaxies · Physics 2024-02-12 J. Schiappacasse-Ulloa , S. Lucatello , G. Cescutti , E. Carretta

We test the performance of our analysis technique for integrated-light spectra by applying it to seven well-studied Galactic GCs that span a wide range of metallicities. Integrated-light spectra were obtained by scanning the slit of the…

Solar and Stellar Astrophysics · Physics 2017-05-10 S. S. Larsen , J. P. Brodie , J. Strader

We compare our compilation of the W' calcium index for 71 Galactic globular clusters to the widely used Zinn and West (1984 ApJS, 55, 45) [Fe/H] scale and to Carretta and Gratton's (1997 A&A Supplement 121, 95) scale from high-dispersion…

Astrophysics · Physics 2009-10-05 G. A. Rutledge , J. E. Hesser , P. B. Stetson

In a series of three papers, we investigate the current status of published metallicities for open clusters that were derived from a variety of photometric and spectroscopic methods. The current article focuses on spectroscopic methods. The…

Astrophysics of Galaxies · Physics 2014-01-10 U. Heiter , C. Soubiran , M. Netopil , E. Paunzen

We present a new calibration of the Calcium II Triplet equivalent widths versus [Fe/H], constructed upon K giant stars in the Galactic bulge. This calibration will be used to derive iron abundances for the targets of the GIBS survey, and in…

Astrophysics of Galaxies · Physics 2015-08-19 S. Vasquez , M. Zoccali , V. Hill , O. A. Gonzalez , I. Saviane , M. Rejkuba , G. Battaglia

We present mean horizontal branch absolute magnitudes and iron abundances for a sample of 39 globular clusters. These quantities were calculated in an unprecedented homogeneous fashion based on Fourier decomposition of ligt curves of RR…

Solar and Stellar Astrophysics · Physics 2023-06-05 Armando Arellano Ferro

We have obtained spectra of 102 red giant branch (RGB) stars in the Leo I dwarf spheroidal galaxy (dSph) and 74 RGB stars in the Leo II dSph using LRIS on the Keck I 10-meter Telescope. We report on the calcium abundances [Ca/H] derived…

Astrophysics · Physics 2008-11-26 Tammy L. Bosler , Tammy A. Smecker-Hane , Peter B. Stetson

Although the globular clusters in the Milky Way have been studied for a long time, a significant fraction of them lack homogeneous metallicity and radial velocity measurements. In an earlier paper we presented the first part of a project to…

Astrophysics of Galaxies · Physics 2018-11-07 S. Vásquez , I. Saviane , E. V. Held , G. S. Da Costa , B. Dias , M. Gullieuszik , B. Barbuy , S. Ortolani , M. Zoccali

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 investigate aluminum abundance variations in the stellar populations of globular clusters using both literature measurements of sodium and aluminum and APOGEE measurements of nitrogen and aluminum abundances. For the latter, we show that…