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We investigate the cosmic age problem associated with 9 extremely old globular clusters in M31 galaxy and 1 very old high-$z$ quasar APM 08279 + 5255 at $z=3.91$. These 9 globular clusters have not been used to study the cosmic age problem…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-09 Shuang Wang , Xiao-Dong Li , Miao Li

Very deep images of the Galactic globular cluster M4 (NGC 6121) through the F606W and F814W filters were taken in 2001 with the WFPC2 on board the HST. A first published analysis of this data set (Richer et al. 2002) produced the result…

Astrophysics · Physics 2009-11-10 G. De Marchi , F. Paresce , O. Straniero , P. G. Prada Moroni

In this paper we discuss the age and spatial distribution of young (age$<$1Gyr) SMC and LMC clusters using data from the Magellanic Cloud Photometric Surveys. Luminosities are calculated for all age-dated clusters. Ages of 324 and 1193…

Astrophysics of Galaxies · Physics 2015-05-18 Katharina Glatt , Eva K. Grebel , Andreas Koch

Recently, a noticeable number of new star clusters was identified in the outskirts of the Large Magellanic Cloud (LMC) populating the so-called star cluster age gap, a space of time (~ 4-12 Gyr) where the only known star cluster is…

Astrophysics of Galaxies · Physics 2021-03-31 Andrés E. Piatti

We present CMDs in the V and I bands for fifteen star clusters in the Small Magellanic Cloud (SMC) based on data taken with the Very Large Telescope (VLT, Chile). We selected these clusters from our previous work, wherein we derived cluster…

Solar and Stellar Astrophysics · Physics 2014-03-05 M. C. Parisi , D. Geisler , G. Carraro , J. J. Clariá , E. Costa , A. J. Grocholski , A. Sarajedini , R. Leiton , A. E. Piatti

This paper is the fourth in a series presenting spectrophotometry of 51 globular cluster candidates, that were detected by Mochejska et al. in the nearby galaxy M33 using the data collected by the DIRECT project. The frames of M33 in this…

Astrophysics · Physics 2007-05-23 Jun Ma , Xu Zhou , Jiansheng Chen , Hong Wu , Xu Kong , Zhaoji Jiang , Suijian Xue , Jin Zhu

(Abridged) The rest-frame near-IR spectra of intermediate age (1-2 Gyr) stellar populations are dominated by carbon based absorption features offering a wealth of information. Yet, spectral libraries that include the near-IR wavelength…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Mariya Lyubenova , Harald Kuntschner , Marina Rejkuba , David R. Silva , Markus Kissler-Patig , Lowell E. Tacconi-Garman

The main goal of this study is to compile a catalogue including the fundamental parameters of a complete sample of 277 star clusters (SCs) of the Large Magellanic Cloud (LMC) observed in the Washington photometric system, including 82…

Solar and Stellar Astrophysics · Physics 2016-01-27 Tali Palma , Luciana V. Gramajo , Juan J. Clariá , Marcelo Lares , Doug Geisler , Andrea V. Ahumada

Buzzoni's (1989) grid of synthetic spectral energy distributions, representative of old stellar populations, was used to derive colours in different photometric systems, and to compare the theoretical predictions with the observational data…

Astrophysics · Physics 2007-05-23 S. Covino , L. E. Pasinetti Fracassini , M. L. Malagnini , A. Buzzoni

We report the results of the observations in the JHK bands of 12 globular clusters in the LMC, and present CMDs down to K=16 for about 450 stars. We merge the data with the BV ones presented in paper I and use the merged data to study the…

To enlarge our growing sample of well-studied star clusters in the Large Magellanic Cloud (LMC), we present CCD Washington CT1 photometry to T1 ~ 23 in the fields of twenty-three mostly unstudied clusters located in the inner disc and outer…

Astrophysics of Galaxies · Physics 2015-06-16 Tali Palma , Juan J. Clariá , Doug Geisler , Andrés E. Piatti , Andrea V. Ahumada

Relative ages for the globular cluster (GC) subpopulations in the Virgo giant elliptical galaxy M87 (NGC 4486) have been determined from Stroemgren photometry obtained with WFPC2 on board HST. Using a variety of population synthesis models,…

Astrophysics · Physics 2009-11-07 Andres Jordan , Patrick Cote , Michael J. West , R. O. Marzke

The large majority of extragalactic star cluster studies done to date have essentially used two or three-passband aperture photometry, combined with theoretical stellar population synthesis models, to obtain age estimates. The accuracy to…

Astrophysics · Physics 2009-11-07 Richard de Grijs

We present integrated photometry and color-magnitude diagrams (CMDs) for 24 star clusters in M33, of which 12 were previously uncataloged. These results are based on Advanced Camera for Surveys observations from the Hubble Space Telescope…

Astrophysics · Physics 2008-11-26 Ata Sarajedini , M. K. Barker , Doug Geisler , Paul Harding , Robert Schommer

The possibility of reconstructing a spherically symmetric inhomogeneous Lemaitre-Tolman-Bondi (LTB) model with $\Lambda$CDM observations has drawn a lot of attention. Recently, a LTB model having the same luminosity-distance and light-cone…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-13 Mi-Xiang Lan , Miao Li , Xiao-Dong Li , Shuang Wang

Theoretical integrated broad-band colors ranging from far-UV to near-IR have been computed for old stellar systems from our evolutionary population synthesis code. These models take into account, for the first time, the detailed systematic…

Astrophysics · Physics 2009-11-07 Hyun-chul Lee , Young-Wook Lee , Brad K. Gibson

Deep stellar photometry of one of the most distant Galactic globular clusters, Palomar 3, based on frames taken with the VLT in Johnson-Cousins broadband V and Ifilters is presented, together with medium-resolution stellar spectroscopy in…

Astrophysics of Galaxies · Physics 2020-08-03 M. E. Sharina , M. V. Ryabova , M. I. Maricheva , A. S. Gorban

The age of three of the oldest clusters -- M15, M68, M92 -- has been redetermined. We use the latest EOS and opacity data available for calculating both isochrones and zero age horizontal branches and employ the brightness difference…

Astrophysics · Physics 2009-10-28 M. Salaris , S. Degl'Innocenti , A. Weiss

We investigated the absolute age of the Galactic globular cluster M71 (NGC 6838) by using optical ground-based images (u',g',r',i',z') collected with the MegaCam camera at the Canada-France-Hawaii-Telescope (CFHT). We performed a robust…

Colour-magnitude diagrams are presented for the first time for L32, L38, K28 (L43), K44 (L68) and L116, which are clusters projected onto the outer parts of the Small Magellanic Cloud (SMC). The photometry was carried out in the Washington…

Astrophysics · Physics 2009-11-06 A. E. Piatti , J. F. C. Santos , J. J. Claria , E. Bica , A. Sarajedini , D. Geisler