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A comparative analysis of Washington color-magnitude diagrams (CMDs) for 14 star clusters and respective surrounding fields in the Large Magellanic Cloud (LMC) outer disk is presented. Each CCD frame including field and respective cluster…

Astrophysics · Physics 2009-10-31 J. F. C. Santos , A. E. Piatti , J. J. Claria , E. Bica , D. Geisler , H. Dottori

We present results based on YJKs photometry of star clusters located in the outermost, eastern region of the Small Magellanic Cloud (SMC). We analysed a total of 51 catalogued clusters whose colour--magnitude diagrams (CMDs), having been…

Astrophysics of Galaxies · Physics 2015-06-24 A. E. Piatti , R. de Grijs , S. Rubele , M. R. Cioni , V. Ripepi , L. Kerber

We have derived ages and metallicities from co-added spectra of 131 globular clusters associated with the giant elliptical galaxy NGC 4472. Based upon a calibration with Galactic globular clusters, we find that our sample of globular…

We present new age and distance determinations for the Galactic Globular Clusters M55 and M5, using the luminosity function method (Jimenez & Padoan 1996, Padoan & Jimenez 1997). We find an age of $11.8 \pm 1.5$ Gyr for M55 and $11.1 \pm…

Astrophysics · Physics 2009-10-30 R. Jimenez , P. Padoan

We investigate current problems in obtaining reliable ages for old stellar systems based on stellar population synthesis modelling of their integrated spectra. In particular, we address the large ages derived for the globular cluster 47…

Astrophysics · Physics 2007-05-23 Alexandre Vazdekis , Maurizio Salaris , Nobuo Arimoto , James A. Rose

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

We present a result of age estimation for star clusters in M33. We obtain color-magnitude diagrams (CMDs) of resolved stars in 242 star clusters from the HST/WFPC2 images. We estimate ages of 100 star clusters among these, by fitting the…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-05 Won-Kee Park , Hong Soo Park , Myung Gyoon Lee

Establishing the reliability with which stellar population parameters can be measured is vital to extragalactic astronomy. Galactic GCs provide an excellent medium in which to test the consistency of Single Stellar Population (SSP) models…

Astrophysics · Physics 2008-11-26 Jon T. Mendel , Robert N. Proctor , Duncan A. Forbes

We have used Washington photometry for 90 star cluster candidates of small angular size -typically ~ 11" in radius- distributed within nine selected regions in the inner disc of the Large Magellanic Cloud (LMC) to disentangle whether they…

Astrophysics of Galaxies · Physics 2015-06-19 Andres E. Piatti

Globular cluster age estimates based on the absolute magnitude of the main sequence turn-off (\mvto) are generally considered to be the most reliable from a theoretical viewpoint. However, the difficulty in determining \mvto\ in observed…

Astrophysics · Physics 2007-05-23 Brian Chaboyer , Pierre Demarque , Peter Kernan , Lawrence M. Krauss , Ata Sarajedini

Mayall II = G1 is one of the most luminous globular clusters (GCs) in M31. Here, we determine its age and mass by comparing multicolor photometry with theoretical stellar population synthesis models. Based on far- and near-ultraviolet GALEX…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Jun Ma , Richard de Grijs , Zhou Fan , Soo-Chang Rey , Zhenyu Wu , Xu Zhou

M31 globular cluster B379 is the first extragalactic cluster, the age of which was determined by main-sequence photometry. In this method, the age of a cluster is obtained by fitting its CMD with stellar evolutionary models. However,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Jun Ma , Zhenyu Wu , Song Wang , Zhou Fan , Xu Zhou , Jianghua Wu , Zhaoji Jiang , Jiansheng Chen

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 review five independent techniques which are used to set the distance scale to globular clusters, including subdwarf main sequence fitting utilizing the recent Hipparcos parallax catalogue. These data together all indicate that globular…

Astrophysics · Physics 2009-10-30 Brian Chaboyer , P. Demarque , Peter J. Kernan , Lawrence M. Krauss

Aim: We aim to estimate the age and reddening parameters of already identified star clusters within the Small Magellanic Cloud (SMC) in a consistent way using available photometric data, classify them based on their mass and strength, and…

Astrophysics of Galaxies · Physics 2018-09-12 P. K. Nayak , A. Subramaniam , S. Choudhury , Ram Sagar

An isophotal atlas of 75 star cluster pairs and multiplets in the Small Magellanic Cloud is presented, comprising 176 objects. They are concentrated in the SMC main body. The isophotal contours were made from Digitized Sky Survey images and…

Astrophysics · Physics 2009-10-31 M. R. de Oliveira , C. M. Dutra , E. Bica , H. Dottori

Current stellar population models have arguably the largest uncertainties in the near-IR wavelength range, partly due to a lack of large and well calibrated empirical spectral libraries. In this paper we present a project, which aim it is…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Mariya Lyubenova , Harald Kuntschner , Marina Rejkuba , David R. Silva , Markus Kissler-Patig , Lowell E. Tacconi-Garman , Soeren S. Larsen

We present 100 multiple cluster candidates selected from the OGLE catalog of star clusters in the Large Magellanic Cloud. Statistical analysis shows that the significant fraction of these objects may constitute physical systems. Coeval ages…

Astrophysics · Physics 2007-05-23 G. Pietrzynski , A. Udalski

We present BV photometry of the Galactic globular cluster NGC 5286, based on 128 V frames and 133 B frames, and covering the entire face of the cluster. Our photometry reaches almost two magnitudes below the turn-off level, and is…

We present the first results of a large ACS Survey of Galactic globular clusters. This Hubble Space Telescope (HST) Treasury project is designed to obtain photometry with S/N > ~10 for main sequence stars with masses > ~0.2Msun in a sample…