Related papers: The age of the oldest globular clusters
Aim of this study is to infer the age of the Galactic Disk by means of the ages of old open clusters, and comment on some recent claims that the Galactic Disk can be older than the Halo. To this purpose, we analyze the Color-Magnitude…
We discuss some of the key open questions regarding the formation and evolution of globular clusters (GCs) during galaxy formation and assembly within a cosmological framework. The current state-of-the-art for both observations and…
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…
Globular clusters (GCs) are among the oldest objects in the Universe for which an age can be directly measured, thus playing an important cosmological role. This age, on the other hand, depends sensitively on the He abundance, which cannot…
In this paper we apply a Bayesian technique to determine the best fit of stellar evolution models to find the main sequence turn off age and other cluster parameters of four intermediate-age open clusters: NGC 2360, NGC 2477, NGC 2660, and…
A recent study shows, from an empirical deduction, that the number and the presence of the blue straggler stars (BSS) in an open cluster follow a function whose components are the ratio between age and the relaxation time, $\it f$, and a…
The all-sky Milky Way Star Clusters (MWSC) survey provides uniform and precise ages and other parameters for a variety of clusters in the Solar Neighbourhood. We construct the cluster age distribution, investigate its spatial variations,…
Surface brightness profiles for 23 M31 star clusters were measured using images from the Wide Field Planetary Camera 2 on the Hubble Space Telescope, and fit to two types of models to determine the clusters' structural properties. The…
The global properties of all known Galactic globular clusters are examined. The relationship between the luminosities and the metallicities of Galactic globular clusters is found to be complex. Among luminous clusters there is a correlation…
We derive ages, metallicities and [alpha/Fe] ratios from the integrated spectra of 23 globular clusters in M31, by employing multivariate fits to two stellar population models. In parallel we analyze spectra of 21 Galactic globular clusters…
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…
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…
A meta-analysis of seismic ages determined for individual stars in the well-studied open and globular clusters NGC 6819, NGC 6791, M67, M4, M19, M80, and M9 reveals both high variance across measurements and significant discrepancy with…
Spectra of galaxies contain an enormous amount of information about the relative mixture of ages and metallicities of constituent stars. We present a comprehensive study designed to extract the maximum information from spectra of data…
We present the results of combining Hubble Space Telescope optical photometry with ground-based Ks-band photometry from the Gemini imagers NIRI and FLAMINGOS-I to study the globular-cluster populations in four early-type galaxies that are…
The ages of the most common stars - low-mass (cool) stars like the Sun, and smaller - are difficult to derive because traditional dating methods use stellar properties that either change little as the stars age or are hard to measure. The…
We use new WFC3 observations of the nearby grand design spiral galaxy M83 to develop two independent methods for estimating the ages of young star clusters. The first method uses the physical extent and morphology of Halpha emission to…
Currently there are two main techniques for independently determining the ages of stellar populations: main sequence evolution theory (via cluster isochrones) and white dwarf cooling theory. Open clusters provide the ideal environment for…
The number of known globular clusters in the Galactic bulge has been increasing steadily thanks to different new surveys. The aim of this study is to provide a census of the newly revealed globular clusters in the Galactic bulge, and…
Globular cluster ages are more than just lower limits to the age of the universe; the distribution of ages constraints the timescales for galaxy formation and chemical evolution. Globular cluster populations with different metallicities…