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Related papers: Evidence for metallicity spreads in three massive …

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G1, also known as Mayall II, is one of the most massive star clusters in M31. Its mass, ellipticity, and location in the outer halo make it a compelling candidate for a former nuclear star cluster. This paper presents an integrated light…

Astrophysics of Galaxies · Physics 2021-01-27 Charli M. Sakari , Matthew D. Shetrone , Andrew McWilliam , George Wallerstein

We present a study of the stellar parameters and iron abundances of 18 giant stars in 6 open clusters. The analysis was based on high-resolution and high-S/N spectra obtained with the UVES spectrograph (VLT-UT2). The results complement our…

Solar and Stellar Astrophysics · Physics 2015-06-03 N. C. Santos , C. Lovis , J. Melendez , M. Montalto , D. Naef , G. Pace

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…

$\omega$ Cen is a rare example of a globular cluster where the iron abundance of the stars spans more than one order of magnitude. Many spectroscopic investigations of its red-giant- and sub-giant- branches have revealed multiple peaks in…

Solar and Stellar Astrophysics · Physics 2021-09-29 M. Latour , A. Calamida , T. -O. Husser , S. Kamann , S. Dreizler , J. Brinchmann

High resolution spectra of five stars in the bulge globular cluster NGC 6528 were obtained at the 8m VLT UT2-Kueyen telescope with the UVES spectrograph. Out of the five stars, two of them showed evidence of binarity. The target stars…

Astrophysics · Physics 2009-11-10 M. Zoccali , B. Barbuy , V. Hill , S. Ortolani , A. Renzini , E. Bica , Y. Momany , L. Pasquini , D. Minniti , R. M. Rich

Following on from our discovery of a significant population of M31 outer halo globular clusters (GCs), and updates to the Revised Bologna Catalogue of M31 GCs, we investigate the GC system of M31 out to an unprecedented radius (~120kpc). We…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 A. P. Huxor , A. M. N. Ferguson , N. R. Tanvir , M. J. Irwin , A. D. Mackey , R. A. Ibata , T. Bridges , S. C. Chapman , G. F. Lewis

This study investigates the metallicity distribution in M31 and M33 by using the near-infrared color index $J-K$ of tip-red-giant-branch (TRGB) of the member stars from \cite{2021ApJ...907...18R} after removing the foreground dwarf stars by…

Astrophysics of Galaxies · Physics 2025-04-29 Ying Li , Biwei Jiang , Yi Ren

We have obtained medium-resolution infrared K band spectra of 44 giants in seven heavily reddened clusters in the Galactic bulge, as well as 12 giants in omega Centauri. We measure the equivalent widths of the Na doublet, the Ca triplet,…

Astrophysics · Physics 2009-11-10 Andrew W. Stephens , Jay A. Frogel

We use Chandra X-ray data to measure the metallicity of the intracluster medium (ICM) in 245 massive galaxy clusters selected from X-ray and Sunyaev-Zel'dovich (SZ) effect surveys, spanning redshifts $0<z<1.2$. Metallicities were measured…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-17 Adam B. Mantz , Steven W. Allen , R. Glenn Morris , Aurora Simionescu , Ondrej Urban , Norbert Werner , Irina Zhuravleva

We analyze the structural parameters of the largest-available sample of spatially resolved extragalactic globular clusters. The images of M31 GCs were found in a search of HST archival data, described in a companion paper. We measure the…

Astrophysics · Physics 2007-05-23 P. Barmby , S. Holland , J. P. Huchra

We utilise the final catalogue from the Pan-Andromeda Archaeological Survey to investigate the links between the globular cluster system and field halo in M31 at projected radii $R_p=25-150$ kpc. In this region the cluster radial density…

We describe a method by which the abundance of metals and the reddening of globular clusters are simultaneously derived. The method is based on the analysis of the shape of the red giant branch and V magnitude of the horizontal branch on…

Astrophysics of Galaxies · Physics 2015-05-13 A. N. Gerashchenko

Size differences of approx. 20% between red (metal-rich) and blue (metal-poor) sub-populations of globular clusters have been observed, generating an ongoing debate as to weather these originate from projection effects or the difference in…

Astrophysics of Galaxies · Physics 2015-06-11 Anna C. Sippel , Jarrod R. Hurley , Juan P. Madrid , William E. Harris

To determine the nature of the recently discovered, ring-like stellar structure at the Galactic anticenter, we have collected spectra of a set of presumed constituent M giants selected from the 2MASS point source catalog. Radial velocities…

Using Monte Carlo simulations of globular clusters we developed a method separating metallicity effects from age effects on observed integrated ugriz colors. We demonstrate that these colors do not evolve with time significantly after an…

Instrumentation and Methods for Astrophysics · Physics 2015-06-09 Christoph Euler

The purpose of this study is to carry out a thorough investigation of the changes in morphology of the red giant branch (RGB) of Galactic globular clusters (GGC) as a function of metallicity, in the V,I bands. To this aim, two key points…

Astrophysics · Physics 2007-05-23 Ivo Saviane , Alfred Rosenberg , Giampaolo Piotto , Antonio Aparicio

High resolution spectra of 123 red giant stars in the globular cluster M13 and 64 red giant stars in M92 were obtained with Hectochelle at the MMT telescope. Emission and line asymmetries in Halpha, and Ca K are identified, characterizing…

Solar and Stellar Astrophysics · Physics 2009-11-13 Sz. Mészáros , A. K. Dupree , T. Szalai

In this paper, we present a detailed high-resolution spectroscopic study of post main sequence stars in the Globular Cluster M68. Our sample, which covers a range of 4000 K in $T_{eff}$, and 3.5 dex in $log(g)$, is comprised of members from…

Solar and Stellar Astrophysics · Physics 2015-06-03 Marc Schaeuble , George Preston , Chris Sneden , I. B. Thompson , S. A. Shectman , G. S. Burley

The properties of a stellar grouping that is ~ 3.5 kpc to the north east of the center of M31 is examined. This structure has (1) a surface brightness that is lower than the surrounding disk, (2) a more-or-less round appearance, (3) a size…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 T. J. Davidge