Related papers: 47 Tuc: The Spectroscopic Versus CMD Age Discrepan…
We present new age and mass estimates for 920 stellar clusters in the Large Magellanic Cloud (LMC) based on previously published broad-band photometry and the stellar cluster analysis package, MASSCLEANage. Expressed in the generic fitting…
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…
The main sequence turnoff luminosity is the best stellar `clock' which can be used to determine the absolute ages of globular clusters. This is due to the fact that it is generally assumed that the luminosity and lifetimes of main sequence…
A new method to derive age differences between the various super star clusters observed in starburst galaxies using the two color diagram (B-H) vs (H-K) is presented. This method offers a quick and easy way to differentiate very young and…
We present deep photometric observations of the open cluster NGC 2477 using HST/WFPC2. By identifying seven cluster white dwarf candidates, we present an analysis of the white dwarf age of this cluster, using both the traditional method of…
Comparing models of Simple Stellar Populations (SSP) with observed line strengths generally provides a tool to break the age-metallicity degeneracy in elliptical galaxies. Due to the wide range of Balmer line strengths observed, ellipticals…
Stellar ages are critical for understanding the temporal evolution of a galaxy. We calculate the ages of over 6000 red giant branch stars in the Large Magellanic Cloud (LMC) observed with SDSS-IV / APOGEE-S. Ages are derived using…
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…
Cosmic chronometers may be used to measure the age difference between passively evolving galaxy populations to calculate the Hubble parameter H(z). The age estimator emerges from the relationship between the amplitude of the rest frame…
We take a critical look at the lithium depletion boundary (LDB) technique that has recently been used to derive the ages of open clusters. We identify the sources of experimental and systematic error and show that the probable errors are…
Using the Hubble Space Telescope, we have obtained the first color-magnitude diagram (CMD) to reach the main-sequence turnoff of the Galactic globular cluster NGC 6388. From a comparison between the cluster CMD and 47 Tucanae's, we find…
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…
We present UBVI photometry for the old open cluster Collinder 261. From comparison of the observed colour-magnitude diagrams with simulations based on stellar evolutionary models we derive in a self consistent way reddening, distance, and…
Main sequence turn-off (MSTO) stars are good tracers of Galactic populations since their ages can be reliably estimated from atmospheric parameters. Based on the GALAH survey, we use the Yale Rotation Evolution Code to determine ages of…
47 Tuc was the first globular cluster observed to be $\gamma$-ray bright, with the $\gamma$-rays being attributed to a population of unresolved millisecond pulsars (MSPs). Recent kinematic data, combined with detailed simulations, appears…
We present a deep near-infrared color--magnitude diagram of the Galactic globular cluster 47 Tucanae, obtained with the Visible and Infrared Survey Telescope for Astronomy (VISTA) as part of the VISTA near-infrared Y, J, K_s survey of the…
Analysing 9 years of Fermi-LAT observations, we recently studied the spectral properties of the prominent globular cluster 47 Tuc (Brown et al. 2018). In particular, we investigated several models to explain the observed gamma-ray emission,…
Constraints on the formation and evolution of the Milky Way Galaxy require multi-dimensional measurements of kinematics, abundances, and ages for a large population of stars. Ages for luminous giants, which can be seen to large distances,…
Our picture of the age-metallicity relation for Milky Way globular clusters (MWGCs) is still highly incomplete, and the majority of MWGCs lack self-consistent age measurements. Here, we exploit deep, homogenous multi-epoch Hubble Space…
In this paper we analyse different chronometers based on the models of chemical evolution developed in Chamcham, Pitts \& Tayler (1993; hereafter CPT) and Chamcham \& Tayler (1994; hereafter CT). In those papers we discussed the ability of…