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Related papers: Ages of LMC Star Clusters using ASAD$_2$

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We present a new method to compute stellar ages in Globular Clusters (GC) that is ten times more precise than the traditional isochrone fitting procedure. The method relies on accurate stellar evolutionary tracks and on photometry for GCs…

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

The optical integrated spectra of three LMC young stellar clusters (NGC 1984, NGC 1994 and NGC 2011) exhibit concave continua and prominent molecular bands which deviate significantly from the predictions of single stellar population (SSP)…

Astrophysics of Galaxies · Physics 2017-08-30 Randa S. Asa'd , Alexandre Vazdekis , Miguel Cervino , Noelia E. D. Noel , Michael A. Beasley , Mahmoud Kassab

The Milky Way's nuclear star cluster (NSC) is a unique laboratory to study the formation and evolution of dense stellar systems around a supermassive black hole. Previous work suggests that most stars in the NSC are old; however, the…

Ages have been derived for 55 globular clusters (GCs) from overlays of isochrones onto the turnoff photometry, assuming distances based on fits of zero-age horizontal branch (ZAHB) models to the lower bound of the observed distributions of…

Astrophysics of Galaxies · Physics 2013-10-14 Don A. Vandenberg , Karsten Brogaard , Ryan Leaman , Luca Casagrande

Observational tests of stellar and Galactic chemical evolution call for the joint knowledge of a star's physical parameters, detailed element abundances, and precise age. For cool main-sequence (MS) stars the abundances of many elements can…

Solar and Stellar Astrophysics · Physics 2019-01-09 M. Fouesneau , H. -W. Rix , T. von Hippel , D. W. Hogg , H. Tian

We present a morphological analysis of the feature-rich 2MASS LMC color-magnitude diagram, identifying Galactic and LMC populations and estimating the density of LMC populations alone. We also present the projected spatial distributions of…

Astrophysics · Physics 2009-10-31 Sergei Nikolaev , Martin D. Weinberg

Recent discoveries have put the picture of stellar clusters being simple stellar populations into question. In particular, the color-magnitude diagrams of intermediate age (1-2 Gyr) massive clusters in the Large Magellanic Cloud (LMC) show…

Astrophysics of Galaxies · Physics 2015-06-23 Florian Niederhofer , Michael Hilker , Nate Bastian , Esteban Silva-Villa

We present new high signal-to-noise spectroscopic data on the M31 globular cluster system, obtained with the Hectospec multifiber spectrograph on the 6.5m MMT. More than 300 clusters have been observed at a resolution of 5A. The primary…

Astrophysics of Galaxies · Physics 2015-05-27 Nelson Caldwell , Ricardo Schiavon , Heather Morrison , James A. Rose , Paul Harding

We present an analysis of Two Micron All Sky Survey (2MASS) calibration photometry of the old open cluster M67 (NGC 2682). The proper motion-cleaned color-magnitude diagram (CMD) resulting from these data extends ~3 magnitudes deeper than…

Solar and Stellar Astrophysics · Physics 2011-02-11 Ata Sarajedini , Aaron Dotter , Allison Kirkpatrick

We present a new method of predicting the ages of galaxies using a machine learning (ML) algorithm with the goal of providing an alternative to traditional methods. We aim to match the ability of traditional models to predict the ages of…

Astrophysics of Galaxies · Physics 2024-06-14 Laura. J. Hunt , Kevin. A. Pimbblet , David. M. Benoit

We present integrated JHK_s 2MASS photometry and a compilation of integrated-light optical photoelectric measurements for 84 star clusters in the Magellanic Clouds. These clusters range in age from ~200 Myr to >10 Gyr, and have [Fe/H]…

Astrophysics · Physics 2009-11-13 P. M. Pessev , P. Goudfrooij , T. H. Puzia , R. Chandar

(ABRIDGED) We assess the systematic uncertainties in (young) cluster age, mass, and - to a lesser extent - extinction and metallicity determinations, based on broad-band imaging observations with the Hubble Space Telescope. Our aim here is…

We define a method for analysis of the integrated spectra of extra-galactic globular clusters that provides more reliable measures of age, metallicity and alpha-element abundance ratio than have so far been achieved. The method involves the…

Astrophysics · Physics 2009-11-10 Robert N. Proctor , Duncan A. Forbes , Michael A. Beasley

Integrated spectroscopy of a sample of 17 blue concentrated Large Magellanic Cloud (LMC) clusters is presented and its spectral evolution studied. The spectra span the range ~3600-6800A with a resolution of ~14A FWHM, being used to…

Astrophysics · Physics 2009-11-11 J. F. C. Santos , J. J. Claria , A. V. Ahumada , E. Bica , A. E. Piatti , M. C. Parisi

We have constrained the age of the globular cluster S312 in the Andromeda galaxy (M31) by comparing its multicolor photometry with theoretical stellar population synthesis models. This is both a check on the age of this globular cluster, as…

Astrophysics · Physics 2011-02-11 Jun Ma , Yanbin Yang , David Burstein , Zhou Fan , Zhenyu Wu , Xu Zhou , Jianghua Wu

The color-magnitude diagrams (CMDs) of three intermediate-age LMC clusters, NGC 2173, SL556 and NGC2155 are analyzed to determine their age and metallicity basing on Padova stellar models. Synthetic CMDs are compared with cluster data. The…

Astrophysics · Physics 2009-11-07 G. Bertelli , E. Nasi , L. Girardi , C. Chiosi , M. Zoccali , C. Gallart

In the quest for the formation and evolution of galaxy clusters, Rakos and co-workers introduced a spectrophotometric method using the modified Str\"omgren photometry. But with the considerable debate toward the project's abilities, we…

Astrophysics of Galaxies · Physics 2012-01-12 Yuvraj Harsha Sreedhar , Andrew P. Odell , Karl D. Rakos , Gerhard Hensler , Werner W. Zeilinger

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 present estimates of stellar age and mass for 0.93 million Galactic disk main sequence turn-off and sub-giant stars from the LAMOST Galactic Spectroscopic Surveys. The ages and masses are determined by matching with stellar isochrones…

Using mock spectra based on Vazdekis/MILES library fitted within the wavelength region 3600-7350\AA, we analyze the bias and scatter on the resulting physical parameters induced by the choice of fitting algorithms and observational…

Astrophysics of Galaxies · Physics 2018-05-23 Junqiang Ge , Renbin Yan , Michele Cappellari , Shude Mao , Hongyu Li , Youjun Lu
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