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We present results from the largest CaII triplet line metallicity study of Small Magellanic Cloud (SMC) field red giant stars to date, involving 3037 objects spread across approximately 37.5 sq. deg., centred on this galaxy. We find a…

Astrophysics of Galaxies · Physics 2015-06-19 P. D. Dobbie , A. A. Cole , A. Subramaniam , S. Keller

We present theoretical evolutionary sequences of intermediate mass stars (M=3-6.5 solar masses) with metallicity Z=0.004. Our goal is to test whether the self-enrichment scenario by massive Asymptotic Giant Branch stars may work for the…

Astrophysics · Physics 2008-01-18 Paolo Ventura Francesca D'Antona

We present results of high resolution (~ 55000) spectral observations of 830 photometrically pre-selected candidate red giants in the magnitude range of V = 9-12. We develop a pipeline for automated determination of the stellar atmospheric…

Solar and Stellar Astrophysics · Physics 2015-05-20 Dmitry Bizyaev , Verne V. Smith , Katia Cunha

We demonstrate that low resolution CaII triplet (CaT) spectroscopic estimates of the overall metallicity ([Fe/H]) of individual Red Giant Branch (RGB) stars in two nearby dwarf spheroidal galaxies (dSphs) agree to +-0.1-0.2 dex with…

Astrophysics · Physics 2009-11-13 G. Battaglia , M. Irwin , E. Tolstoy , V. Hill , A. Helmi , B. Letarte , P. Jablonka

In the updated APOGEE-Kepler catalog, we have asteroseismic and spectroscopic data for over 3000 first ascent red giants. Given the size and accuracy of this sample, these data offer an unprecedented test of the accuracy of stellar models…

Photoelectric photometry on the extended Stromgren system (uvbyCa) is presented for 7 giants and 21 main sequence stars in the old open cluster, NGC 752. Analysis of the hk data for the turnoff stars yields a new determination of the…

Astrophysics · Physics 2009-11-11 Barbara J. Anthony-Twarog , Bruce A. Twarog

The metal content of clusters of galaxies and its relation to their stellar content is revisited making use of a cluster sample for which all four basic parameters are homogeneously measured within consistent radii, namely core-excised…

Astrophysics of Galaxies · Physics 2015-06-22 A. Renzini , S. Andreon

We present results obtained from Stromgren photometry of 13 young (~30-220 Myr) Magellanic Cloud (MC) clusters, most of them lacking in the literature from direct metallicity measurements. We derived for them [Fe/H] values from a…

Astrophysics of Galaxies · Physics 2019-01-09 A. E. Piatti , G. Pietrzyński , W. Narloch , M. Górski , D. Graczyk

We analyze spectra of 18 stars belonging to the faintest subgiant branch in omega Centauri (the SGB-a), obtained with GIRAFFE@VLT at a resolution o R~17000 and a S/N ratio between 25 and 50. We measure abundances of Al, Ba, Ca, Fe, Ni, Si,…

Astrophysics of Galaxies · Physics 2015-05-30 E. Pancino , A. Mucciarelli , P. Bonifacio , L. Monaco , L. Sbordone

We present an empirical method to derive photometric metallicity, reddening and distance to old stellar populations by using a few major features of the Red Giant Branch (RGB) in near IR color magnitude diagrams. We combine the observed RGB…

Astrophysics · Physics 2008-11-26 F. R. Ferraro , E. Valenti , L. Origlia

Based on high resolution and high signal-to-noise ratio (S/N) spectra analysis of 90 solar type stars, we have established several new metallicity calibrations in Teff range [5600, 6500] K based on red spectra with the wavelength range of…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 J. K. Zhao , G. Zhao , Y. Q. Chen , A. L. Luo

We present a rest-frame UV-optical stacked spectrum representative of massive quiescent galaxies at $1.0<z<1.3$ with log$(M_*/\rm{M_\odot})>10.8$. The stack is constructed using VANDELS survey data, combined with new KMOS observations. We…

Low resolution spectra have been used to measure individual metal abundances of RR Lyrae stars in NGC 6441, a Galactic globular cluster known to have very unusual horizontal branch morphology and periods of the RR Lyrae stars for its high…

We summarize a selection process to identify red giants in the direction of the southern warp of the Galactic disk, employing VI_C photometry and multi-object spectroscopy. We also present results from follow-up high-resolution, high-S/N…

Astrophysics · Physics 2008-11-26 Bruce W. Carney , David Yong , Luisa de Almeida , Patrick Seitzer

We analysed high-resolution UVES spectra of six stars belonging to the subgiant branch of omega Centauri, and derived abundance ratios of 19 chemical elements (namely Al, Ba, C, Ca, Co, Cr, Cu, Fe, La, Mg, Mn, N, Na, Ni, Sc, Si, Sr, Ti, and…

Solar and Stellar Astrophysics · Physics 2015-05-20 E. Pancino , A. Mucciarelli , L. Sbordone , M. Bellazzini , L. Pasquini , L. Monaco , F. R. Ferraro

Copper abundances are presented for 40 red-giant stars in Omega Cen as well as 15 red-giant members of the globular clusters NGC288, NGC362, NGC3201, NGC6752, and M4. A comparison with the halo field star pattern indicates that, unlike the…

Astrophysics · Physics 2016-08-30 K. Cunha , V. V. Smith , N. B. Suntzeff , J. E. Norris , G. S. Da Costa , B. Plez

It is still being debated whether the well-known metallicity - giant planet correlation for dwarf stars is also valid for giant stars. For this reason, having precise metallicities is very important. Different methods can provide different…

Earth and Planetary Astrophysics · Physics 2015-06-16 A. Mortier , N. C. Santos , S. G. Sousa , V. Zh. Adibekyan , E. Delgado Mena , M. Tsantaki , G. Israelian , M. Mayor

Metallicities ([Fe/H]) from low resolution spectroscopy obtained with the Very Large Telescope (VLT) are presented for 98 RR Lyrae and 3 short period Cepheids in the bar of the Large Magellanic Cloud. Our metal abundances have typical…

Astrophysics · Physics 2009-11-10 R. G. Gratton , A. Bragaglia , G. Clementini , E. Carretta , L. Di Fabrizio , M. Maio , E. Taribello , -

We have obtained an accurate estimate of the absolute I magnitude of the Tip of the Red Giant Branch (M_I(TRGB)) for the globular cluster Omega Cen, based {\em (a)} on the largest photometric database ever assembled for a globular, by…

Astrophysics · Physics 2007-05-23 Michele Bellazzini , Francesco R. Ferraro , Elena Pancino

High-resolution HST ultra-violet spectra for five B-type stars in the Magellanic Bridge and in the Large and Small Magellanic Clouds have been analysed to estimate their iron abundances. Those for the Clouds are lower than estimates…

Astrophysics · Physics 2009-06-23 P. L. Dufton , R. S. I. Ryans , H. M. A. Thompson , R. A. Street