Related papers: Age Estimates of Universe: from Globular Clusters …
Context: The formation and evolution of disk galaxies are long standing questions in Astronomy. Understanding the properties of globular cluster systems can lead to important insights on the evolution of its host galaxy. Aims: We aim to…
We use evolutionary calculations presented in a recent paper (Cassisi et al. 1998) to predict B,V,I magnitudes for stars in galactic globulars. The effect of the adopted mixing length on stellar magnitudes and colors is discussed, showing…
We present a color-magnitude diagram (CMD) of the globular cluster SKHB-312 in the Andromeda galaxy (M31), obtained with the Advanced Camera for Surveys on the Hubble Space Telescope. The cluster was included in deep observations taken to…
We present colour-magnitude diagrams (CMDs) for a sample of seven young massive clusters in the galaxies NGC 1313, NGC 1569, NGC 1705, NGC 5236 and NGC 7793. The clusters have ages in the range 5-50 million years and masses of 10^5 -10^6…
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…
The ACS Survey of Galactic Globular Clusters is a Hubble Space Telescope (HST) Treasury program designed to provide a new large, deep and homogeneous photometric database. Based on observations from this program, we have measured precise…
We discuss new photometry from high-resolution images of 7 intermediate-age (1-2 Gyr) star clusters in the Large Magellanic Cloud taken with the Advanced Camera for Surveys on board the Hubble Space Telescope. We fit color-magnitude…
We have used the WFPC2 camera on the Hubble Space Telescope to obtain photometry of the outer-halo globular clusters Palomar 3, Palomar 4, and Eridanus. These three are classic examples of the "second parameter" anomaly because of their red…
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%…
We present accurate relative ages for a sample of 55 Galactic globular clusters. The ages have been obtained by measuring the difference between the horizontal branch and the turnoff in two, internally photometrically homogeneous databases.…
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…
This is the first of a series of three papers devoted to the calibration of a few parameters of crucial importance in the modeling of the evolution of intermediate-mass stars, with special attention to the amount of convective core…
In the study of galaxy integrated light, if photometric indicators could extract age and metallicity information of high enough quality, photometry might be vastly more efficient than spectroscopy for the same astrophysical goals. Toward…
We present the recently updated and expanded MASSCLEANcolors, a database of 70 million Monte Carlo models selected to match the properties (metallicity, ages and masses) of stellar clusters found in the Large Magellanic Cloud (LMC). This…
Globular clusters (GCs) provide statistically significant coeval populations of stars spanning various evolutionary stages, allowing robust constraints on stellar evolution model parameters and ages. We analyze eight old Milky Way GCs with…
We present our recent revision of model constructions for the horizontal-branch (HB) morphology of globular clusters, which suggests the HB morphology is more sensitive to age compared to our earlier models. We also present our high…
The ages and metallicities of globular clusters play an important role not just in testing models for their formation and evolution but in understanding the assembly history for their host galaxies. Here we use a combination of imaging and…
The LMC has a rich star cluster system spanning a wide range of ages and masses. One striking feature of the LMC cluster system is the existence of an age gap between 3-10 Gyrs. Four LMC clusters whose integrated colours are consistent with…
We discuss the present state of knowledge and thought concerning the spread in age found among Galactic globular clusters, with some discussion of the implications for what happened during the earliest stages of the formation of the Milky…
Integrated spectroscopy is the method of choice for deriving the ages of unresolved stellar systems. However, hot stellar evolutionary stages, such as hot horizontal branch stars and blue straggler stars (BSSs), can affect the integrated…