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Related papers: The Relative Ages of Galactic Globular Clusters

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Their ubiquity and extreme densities make star clusters probes of prime importance of galaxy evolution. Old globular clusters keep imprints of the physical conditions of their assembly in the early Universe, and younger stellar objects,…

Astrophysics of Galaxies · Physics 2018-05-02 Florent Renaud

Estimating the age of the Universe is an old problem. Rapid progress in observational cosmology in recent years has led to more accurate values of the fundamental parameters. The current most popular model is a flat Universe, with about 30%…

Astrophysics · Physics 2007-05-23 Oleg Y. Gnedin , Ofer Lahav , Martin J. Rees

We extend our previous method to determine globular cluster ages using the luminosity function (Jimenez \& Padoan 1996). We show that the luminosity function depends on both age and distance modulus and that it is possible to distinguish…

Astrophysics · Physics 2016-08-30 Paolo Padoan , Raul Jimenez

A subset of 150 globular clusters in M87 has been selected on the basis of S/N ratio for abundance and age determinations from the sample of Paper I. Indices measuring the strength of the strongest spectral features were determined for the…

Astrophysics · Physics 2009-10-30 Judith G. Cohen , John P. Blakeslee , Anton Ryzhov

We present age measurements for 195 star clusters in the Small Magellanic Cloud based on comparison of integrated colors measured from the Magellanic Clouds Photometric Survey with models of simple stellar populations. We find that the…

Astrophysics · Physics 2008-11-26 Marc Rafelski , Dennis Zaritsky

We present a new technique to determine age and metallicity of old stellar populations (globular clusters and elliptical galaxies) using an iterative principal component analysis on narrow band (Str\"omgren) colors. Our technique is capable…

Astrophysics · Physics 2009-11-11 K. Rakos , J. Schombert , A. Odell

Hickson Compact Groups (HCGs) constitute an interesting extreme in the range of environments in which galaxies are located, as the space density of galaxies in these small groups are otherwise only found in the centres of much larger…

In this Letter, we analyse the distributions of stellar ages in Giant Molecular Clouds (GMCs) in spiral arms, inter-arm spurs, and at large galactic radii, where the spiral arms are relatively weak. We use the results of numerical…

Astrophysics of Galaxies · Physics 2015-06-17 C. L. Dobbs , J. E. Pringle , T. Naylor

Globular clusters (GCs) are among the oldest and densest stellar systems in the Universe, yet how they form remains a mystery. Here we present a suite of cosmological simulations in which both dark-matter-free GCs and dark-matter-rich dwarf…

Globular star clusters that formed at the same cosmic time may have evolved rather differently from a dynamical point of view (because that evolution depends on the internal environment) through a variety of processes that tend…

I discuss the chemical evolution of star clusters, with emphasis on old globular clusters, in relation to their formation histories. Globular clusters clearly formed in a complex fashion, under markedly different conditions from any younger…

Astrophysics of Galaxies · Physics 2015-05-14 Jacco Th. van Loon

We explore the structure of the element abundance--age--orbit distribution of the stars in the Milky Way's low-$\alpha$ disk, by (re-)deriving precise [Fe/H], [X/Fe] and ages, along with orbits, for red clump stars from the APOGEE survey.…

Solar and Stellar Astrophysics · Physics 2019-10-09 Melissa K. Ness , Kathryn V. Johnston , Kirsten Blancato , Hans-Walter Rix , Angus Beane , Jonathan C. Bird , Keith Hawkins

We test the hypothesis that the apparent axis ratio of an elliptical galaxy is correlated with the age of its stellar population. We find that old ellipticals (with estimated stellar ages t > 7.5 Gyr) are rounder on average than younger…

Astrophysics · Physics 2009-11-06 Barbara S. Ryden , Duncan A. Forbes , A. I. Terlevich

Visual and near-infrared colours are used to identify intermediate-age globular cluster in early-type galaxies. In NGC5846 and NGC4365 colour-colour diagrams (V-I vs. V-K) reveal a sub-population in the globular cluster systems with an age…

Globular clusters (GCs) are important tools to rebuild the accretion history of a galaxy. There are newly discovered GCs in the Sagittarius (Sgr) dwarf galaxy, that can be used as probes of the accretion event onto the Milky Way (MW). Our…

Astrophysics of Galaxies · Physics 2021-10-04 E. R. Garro , D. Minniti , M. Gómez , J. Alonso-García

We here present our first attempt to use Globular Clusters as tracers of their parent galaxy's formation history. Globular Cluster Systems of most early-type galaxies feature two peaks in their optical colour distributions. Blue-peak…

Astrophysics · Physics 2009-11-13 Ralf Kotulla , Uta Fritze , Peter Anders

The characteristics of the cluster systems of the Magellanic Clouds, as inferred from integrated properties, are compared with those from individual cluster studies and from the field population. The agreement is generally satisfactory…

Astrophysics · Physics 2007-05-23 G. S. Da Costa

We are using full spectrum fitting to determine the ages and metallicities of Galactic clusters (M67 and globular clusters). We find that the method is very accurate to measure the metallicity. Blue horizontal branches are well identified…

Astrophysics · Physics 2009-11-13 Mina Koleva , Philippe Prugniel , Pierre Ocvirk , Damien Le Borgne

Using the theoretical stellar population synthesis models of BC96, Kong et al. (2003) showed that some BATC colors and color indices could be used to disentangle the age and metallicity effect. They found that there is a very good relation…

Astrophysics · Physics 2014-10-13 Jun Ma , Xu Zhou , Jiansheng Chen

The four main findings about the age and abundance structure of the Milky Way bulge based on microlensed dwarf and subgiant stars are: (1) a wide metallicity distribution with distinct peaks at [Fe/H]=-1.09, -0.63, -0.20, +0.12, +0.41; (2)…

Astrophysics of Galaxies · Physics 2018-08-22 T. Bensby , S. Feltzing , A. Gould , J. C. Yee , J. A. Johnson , M. Asplund , J. Meléndez , S. Lucatello , L. M. Howes