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Related papers: The double RGB in M 2: C, N, Sr and Ba abundances

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We present CH and CN index analysis and C and N abundance calculations based on the low-resolution blue spectra of red giant branch (RGB) stars in the Galactic globular cluster NGC 7089 (M 2). Our main goal is to investigate the C-N…

Solar and Stellar Astrophysics · Physics 2015-06-11 C. Lardo , E. Pancino , A Mucciarelli , A. P. Milone

We obtained FLAMES GIRAFFE+UVES spectra for both first and second-generation red giant branch (RGB) stars in the globular cluster (GC) NGC 362 and used them to derive abundances of 21 atomic species for a sample of 92 stars. The surveyed…

Astrophysics of Galaxies · Physics 2015-06-16 E. Carretta , A. Bragaglia , R. G. Gratton , S. Lucatello , V. D'Orazi , M. Bellazzini , G. Catanzaro , F. Leone , Y. Momany , A. Sollima

We present chemical abundance analysis of a sample of 15 red giant branch (RGB) stars of the Globular Cluster NGC~1851 distributed along the two RGBs of the (v, v-y) CMD. We determined abundances for C+N+O, Na, $\alpha$, iron-peak, and…

Astrophysics of Galaxies · Physics 2015-05-19 Sandro Villanova , Douglas Geisler , Giampaolo Piotto

We present the first chemical analysis of stars on the double subgiant branch (SGB) of the globular cluster NGC 1851. We obtained 48 Magellan IMACS spectra of subgiants and fainter stars covering the spectral region between 3650-6750\AA, to…

Astrophysics of Galaxies · Physics 2015-06-04 C. Lardo , A. P. Milone , A. F. Marino , A. Mucciarelli , E. Pancino , M. Zoccali , M. Rejkuba , R. Carrera , O. Gonzalez

We present CN and CH indices and CaII triplet metallicities for 34 giant stars and chemical abundances for 33 elements in 14 giants in the globular cluster M2. Assuming the program stars are cluster members, our analysis reveals (i) an…

There is increasing evidence for the presence of multiple red giant branches (RGBs) in the color-magnitude diagrams of massive globular clusters (GCs). In order to investigate the origin of this split on the RGB, we have performed new…

We present the abundances of N in a sample of 62 stars on the red giant branch (RGB) in the peculiar globular cluster NGC 1851. The values of [N/Fe] ratio were obtained by comparing the flux measured in the observed spectra with that from…

Astrophysics of Galaxies · Physics 2014-03-05 Eugenio Carretta , Valentina D'Orazi , Raffaele G. Gratton , Sara Lucatello

AIMS. In this paper we present the chemical abundance analysis from high resolution UVES spectra of seventeen bright giant stars of the Globular Cluster M~22. RESULTS. We obtained an average iron abundance of [Fe/H]=-1.76\pm0.02 (internal…

Solar and Stellar Astrophysics · Physics 2015-05-13 A. F. Marino , A. P. Milone , G. Piotto , S. Villanova , L. R. Bedin , A. Bellini , A. Renzini

We present an abundance analysis of 101 subgiant branch (SGB) stars in the globular cluster M22. Using low resolution FLAMES/GIRAFFE spectra we have determined abundances of the neutron-capture strontium and barium and the light element…

We present an empirical s-process abundance distribution derived with explicit knowledge of the r-process component in the low-metallicity globular cluster M22. We have obtained high-resolution, high signal-to-noise spectra for 6 red giants…

Solar and Stellar Astrophysics · Physics 2015-05-30 I. U. Roederer , A. F. Marino , C. Sneden

We present CN and CH band measurements for 137 RGB and AGB stars in the Galactic globular cluster M10. Our measurements come from low resolution spectroscopy taken with the Hydra spectrograph on the WIYN-3.5m telescope. We use these…

Solar and Stellar Astrophysics · Physics 2018-06-12 Jeffrey M. Gerber , Eileen D. Friel , Enrico Vesperini

Several recent studies have reported the detection of an anomalous color spread along the red giant branch (RGB) of some globular clusters (GC) that appears only when color indices including a near ultraviolet band (such as Johnson U or…

Astrophysics of Galaxies · Physics 2015-05-20 C. Lardo , M. Bellazzini , E. Pancino , E. Carretta , A. Bragaglia , E. Dalessandro

We present a detailed chemical composition analysis of 35 red giant stars in the globular cluster M22. High resolution spectra for this study were obtained at five observatories, and analyzed in a uniform manner. We have determined…

There is a growing body of evidence for the presence of multiple stellar populations in some globular clusters, including NGC 1851. For most of these peculiar globular clusters, however, the evidence for the multiple red giant-branches…

Astrophysics of Galaxies · Physics 2014-11-20 Sang-Il Han , Young-Wook Lee , Seok-Joo Joo , Sangmo Tony Sohn , Suk-Jin Yoon , Hak-Sub Kim , Jae-Woo Lee

We observed a sample of 90 red giant branch (RGB) stars in NGC 2808 using FLAMES/GIRAFFE and the high resolution grating with the set up HR21. These stars have previous accurate atmospheric parameters and abundances of light elements. We…

Solar and Stellar Astrophysics · Physics 2018-07-11 Eugenio Carretta , Angela Bragaglia , Sara Lucatello , Raffaele G. Gratton , Valentina D'Orazi , Antonio Sollima

The globular cluster NGC 288 was previously reported to exhibit two distinct red giant branches (RGBs) in the narrow-band Calcium (HK) and Str\"omgren b and y band passes. In order to investigate this phenomenon further, we obtained…

Solar and Stellar Astrophysics · Physics 2015-06-22 Tiffany Hsyu , Christian I. Johnson , Young-Wook Lee , R. Michael Rich

We report the presence of two distinct red giant branches (RGBs) in the globular cluster NGC 288 from the narrow-band calcium and Str\"{o}mgren b & y photometry obtained at the CTIO 4m Blanco telescope. The RGB of NGC 288 is clearly split…

Astrophysics of Galaxies · Physics 2015-05-28 Dong-Goo Roh , Young-Wook Lee , Seok-Joo Joo , Sang-Il Han , Young-Jong Sohn , Jae-Woo Lee

[Abridged] Detailed chemical tagging of individual stellar populations in the Galactic globular cluster (GC) NGC 1851 is presented. Abundances are derived from FLAMES spectra for the largest sample of giants (124) ever analysed in this…

Solar and Stellar Astrophysics · Physics 2015-05-28 Eugenio Carretta , Sara Lucatello , Raffaele Gratton , A. Bragaglia , Valentina D'Orazi

Globular clusters show abundance variations for light elements that are not yet well understood. The preferred explanation involves a self-enrichment scenario, with two subsequent generations of stars. Observations of main sequence stars…

Astrophysics of Galaxies · Physics 2015-05-19 E. Pancino , M. Rejkuba , M. Zoccali , R. Carrera

We present high-precision multi-band photometry for the globular cluster (GC) M2. We combine the analysis of the photometric data obtained from the Hubble Space Telescope UV Legacy Survey of Galactic GCs GO-13297, with chemical abundances…

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