Related papers: Multiple populations in Galactic globular clusters…
The formation of stars with light-element abundance variations in globular clusters and the subsequent dynamical evolution of these multiple populations remains an open question. One of the most widely discussed is the AGB scenario, in…
We present a homogeneous catalogue for blue straggler, red giant branch, horizontal branch and main-sequence turn-off stars in a sample of 35 clusters taken from the ACS Survey for Globular Clusters. As a result of the superior photometry…
The 'chromosome map' diagram (ChM) proved a successful tool to identify and characterize multiple populations (MPs) in 59 Galactic Globular Clusters (GCs). Here, we construct ChMs for 11 GCs of both Magellanic Clouds (MCs) and with…
Globular cluster systems provide valuable fossil records of the formation history of their parent galaxies. This review specifically concentrates on using color distributions of the globular cluster systems of elliptical galaxies to…
This review summarizes the properties of the stellar population in bulges as observed in nearby or distant spiral galaxies. It gives a particular emphasis to the comparison with elliptical galaxies, when possible. The criteria of sample…
Recent work on globular cluster systems in dwarf galaxies outside the Local Group is reviewed. Recent large imaging surveys with the Hubble Space Telescope and follow-up spectroscopy with 8-m class telescopes now allow us to compare the…
Multiple stellar populations in the Milky Way globular clusters manifest themselves with a large variety. Although chemical abundance variations in light elements, including He, are ubiquitous, the amount of these variations is different in…
We discuss, from a statistical point of view, some leading issues that deal with the study of stellar populations in fully or partially unresolved aggregates, like globular clusters and distant galaxies. A confident assessment of the…
The stellar populations of galaxies contain a wealth of detailed information. From the youngest, most massive stars, to almost invisible remnants, the history of star formation is encoded in the stars that make up a galaxy. Extracting some,…
Globular Clusters (GCs) exhibit star-to-star variations in specific elements (e.g., He, C, N, O, Na, Al) that bare the hallmark of high temperature H burning. These abundance variations can be observed spectroscopically and also…
We take a closer look at our published results of determination of ages, metallicities, helium mass fractions and abundances of chemical elements in Galactic globular clusters in order to find possible signatures of the phenomenon of…
Globular clusters were thought to be simple stellar populations, but recent photometric and spectroscopic evidence suggests that the clusters' early formation history was more complicated. In particular, clusters show star-to-star abundance…
This review focuses on how galaxies and their globular cluster systems form. I first discuss the now fairly convincing evidence that some globular clusters form in galaxy starbursts/mergers. One way these observations are valuable is they…
We present a general overview and the first results of the SUMO project (a SUrvey of Multiple pOpulations in Globular Clusters). The objective of this survey is the study of multiple stellar populations in the largest sample of globular…
We present the first evidence of multiple populations in the Galactic globular cluster NGC 6362. We used optical and near-UV Hubble Space Telescope and ground based photometry, finding that both the sub giant and red giant branches are…
We present stellar atmosphere and evolution models of main sequence stars in two stellar populations of the Galactic globular cluster NGC 6752. These populations represent the two extremes of light-element abundance variations in the…
We develop a Bayesian model for globular clusters composed of multiple stellar populations, extending earlier statistical models for open clusters composed of simple (single) stellar populations (vanDyk et al. 2009, Stein et al. 2013).…
The existence of complex stellar populations in some star clusters challenges the understanding of star formation. E.g. the ONC or the sigma Orionis cluster host much older stars than the main bulk of the young stars. Massive star clusters…
We use Cycle 21 Hubble Space Telescope (HST) observations and HST archival ACS Treasury observations of 30 Galactic Globular Clusters to characterize two distinct stellar populations. A sophisticated Bayesian technique is employed to…
We present a detailed analysis of the spatial distribution of the stellar populations in the Galactic globular cluster omega Centauri. Taking advantage of the large photometric catalog published by Pancino et al. (2000), we confirm that…