相关论文: The $\textit{HST}$ Large Programme on NGC$\,$6752 …
We present HST WFPC2 observations, supplemented by ground-based H-alpha data, of the star-cluster populations in two pairs of interacting galaxies, selected for being in very different kinds of encounters seen at different stages. Dynamical…
We constrain the mass-to-light ratios, gas mass fractions, baryon mass fractions and the ratios of total to luminous mass for a sample of eight nearby relaxed galaxy groups and clusters: A262, A426, A478, A1795, A2052, A2063, A2199 and…
Historically, photometry has been largely used to identify stellar populations (MPs) in Globular Clusters (GCs) by using diagrams that are based on colours and magnitudes that are mostly sensitive to stars with different metallicities or…
We present a detailed study of the star cluster population detected in the galaxy NGC922, one of the closest collisional ring galaxies known to date, using HST/WFPC2 UBVI photometry, population synthesis models, and N-body/SPH…
We study the stellar cluster population in two adjacent fields in the nearby, face-on spiral galaxy, M83, using WFC3/HST imaging. The clusters are selected through visual inspection to be centrally concentrated, symmetric, and resolved on…
Wide-field photometry of Galactic globular clusters (GCs) has been investigated to overcome limitations from the small field of view of the Hubble Space Telescope in the study of multiple populations. In particular, 'chromosome maps' (ChMs)…
Most globular clusters in the local group show multiple stellar populations, a pattern defined by variations of several light elements, with some also displaying dispersions in heavy elements. Since helium is the most immediate product of…
We have used a proper combination of multiband high-resolution {\it HST-WFPC2} and wide-field ground based observations to image the galactic globular cluster NGC 6266 (M62). The extensive photometric data set allows us to determine the…
We report on HST/WFPC2 U,V and far-ultraviolet observations of two Galactic Globular Clusters (GGCs), NGC 6205 = M13 and NGC 6093 = M80. Both of these clusters have horizontal-branch (HB) tails that extend to the helium-burning main…
In this second installment of the series, we look at the internal kinematics of the multiple stellar populations of the globular cluster $\omega$ Centauri in one of the parallel Hubble Space Telescope (HST) fields, located at about 3.5…
The discovery both through spectroscopy and photometry of multiple stellar populations in Galactic globular clusters, and in Magellanic Clouds' massive intermediate-age and old clusters, has led to a major change in our views about the…
I-band CCD images of two large regions of the Galactic globular cluster NGC 1261 have been used to construct stellar luminosity functions (LF) for 14000 stars in three annuli from 1.4' from the cluster center to the tidal radius. The LFs…
A significant fraction of stars in both the Galactic field and stellar clusters are members of binary systems. Understanding their properties is therefore essential for a comprehensive view of stellar structure, evolution, and cluster…
We quantify the systematic effects on the stellar mass function which arise from assumptions about the stellar population, as well as how one fits the light profiles of the most luminous galaxies at z ~ 0.1. When comparing results from the…
Context: There is strong evidence that globular cluster systems (GCSs) of massive galaxies are largely assembled by infall/accretion processes. Therefore, we expect the GCSs of isolated elliptical galaxies to be poor. Alhough not completely…
We present colour-magnitude diagrams for two rich (~10^4 Msun) Large Magellanic Cloud star clusters with ages ~10^7 years, constructed from optical and near-infrared data obtained with the Hubble Space Telescope. These data are part of an…
I present the first evidence of multiple populations in the globular cluster (GCs) 47Tucanae based on images collected with the near-infrared camera (NIRCam) on board the James Webb Space Telescope (JWST). While NIRCam photometry is poorly…
We consider the observational signature of the dynamical effects on the luminosity function of globular clusters. For the three best studied systems, in Milky Way, M31, and M87, there is a statistically significant difference between the…
We present V- and I-equivalent HST/WFPC2 stellar photometry of an area in the Large Magellanic Cloud (LMC), located on the western edge of the bar of the galaxy, which accounts for the general background field of its inner disk. The WFPC2…
We identify a vertical extension of the red clump stars in the color magnitude diagram (CMD) of a section of the Large Magellanic Cloud (LMC). After subtracting the principal red clump component, we find a peak in the residual stellar…