相关论文: Extended main sequence turn-off originated from a …

Extended main-sequence turn-offs (eMSTO) are a commonly observed property of young clusters. A global theoretical interpretation for the eMSTOs is still lacking, but stellar rotation is considered a necessary ingredient to explain the…

We present adaptive optics (AO) assisted integral-field spectroscopy of the intermediate-age star cluster NGC 419 in the Small Magellanic Cloud. By investigating the cluster dynamics and the rotation properties of main sequence turn-off…

The discovery of multiple MSs in NGC2808 and Omega Centauri, and multiple SGBs in NGC1851 and NGC6388 has challenged the long-held paradigm that GCs consist of simple stellar populations. This picture has been further complicated by recent…

The most massive elliptical galaxies show a prominent multi-modality in their globular cluster system color distributions. Understanding the mechanisms which lead to multiple globular cluster sub-populations is essential for a complete…

We investigate the long-term dynamical evolution of the internal kinematics of multimass rotating star clusters. We have performed a set of N-body simulations to follow the internal evolution of clusters with different degrees of initial…

We present a detailed study of stellar rotation in the massive 1.5 Gyr old cluster NGC 1846 in the Large Magellanic Cloud. Similar to other clusters at this age, NGC 1846 shows an extended main sequence turn-off (eMSTO), and previous…

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…

We investigate the relationship between the mass of a globular cluster core and the sizes of its various stellar populations in a sample of 56 globular clusters. The number of core red giant branch stars is found to scale sub-linearly with…

The colour-magnitude diagrams of some intermediate-age clusters (1-2 Gyr) star clusters show unexpectedly broad main-sequence turnoffs, raising the possibility that these clusters have experienced more than one episode of star formation.…

A large number of early type galaxies are now known to possess blue and red subpopulations of globular clusters. We have compiled a database of 28 such galaxies exhibiting bimodal globular cluster colour distributions. After converting to a…

We investigate the integrated properties of massive (>10 Msun), rotating, single-star stellar populations for a variety of initial rotation rates (v/vcrit=0.0, 0.2, 0.4, 0.5, and 0.6). We couple the new MESA Isochrone and Stellar Tracks…

Galactic globular clusters are not simple stellar populations. And nothing is simple in their study, basically because we try to reconstruct chains of events that occurred at redshift z > 2-3 by observing these objects at z=0, after a…

Many young and intermediate age massive stellar clusters host bimodal distributions in the rotation rates of their stellar populations, with a dominant peak of rapidly rotating stars and a secondary peak of slow rotators. The origin of this…

NGC 6791 is an old, metal-rich star cluster normally considered to be a disk open cluster. Its red giant branch is broad in color yet, to date, there is no evidence for a metallicity spread among its stars. The turnoff region of the main…

Globular cluster systems (GCS) frequently show a bi-modal distribution of the cluster integrated colours. This work explores the arguments to support the idea that the same feature is shared by the diffuse stellar population of the galaxy…

We investigate the long-term dynamical evolution of two distinct stellar populations of low-mass stars in globular clusters in order to study whether the energy equipartition process can explain the high number of stars harbouring abundance…

Observations of young open clusters show a bimodal distribution of stellar rotation. Sun-like stars in those clusters group into two main sub-populations of fast and slow rotators. Beyond an age of about 500 Myrs, the two populations…

Context. We need to understand the spin evolution of massive stars to compute their internal rotationally induced mixing processes, isolate effects of close binary evolution, and predict the rotation rates of white dwarfs, neutron stars and…

We measure the diversity of galaxy groups and clusters with mass M>1E13/h Msun, in terms of the star formation history of their galaxy populations, for the purpose of constraining the mass scale at which environmentally-important processes…

We have carried out a set of Monte Carlo simulations to study a number of fundamental aspects of the dynamical evolution of multiple stellar populations in globular clusters with different initial masses, fractions of second generation (2G)…