相关论文: Multiple Stellar Populations in NGC 2808: a Case S…

We have used ESO telescopes at La Silla and the Hubble Space Telescope (HST) in order to obtain accurate B,V,I CCD photometry for the stars located within 200" (~= 2 half-mass radii, r_h = 1.71') from the center of the cluster NGC 6101.…

A combination of two unsupervised machine learning algorithms, DBSCAN and GMM are used to find members with a high probability of twelve open clusters, M38, NGC2099, Coma Ber, NGC752, M67, NGC2243, Alessi01, Bochum04, M34, M35, M41, and…

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…

Stellar population models are commonly calculated using star clusters as calibrators for those evolutionary stages that depend on free parameters. However, discrepancies exist among different models, even if similar sets of calibration…

Most Globular Clusters so far examined host (at least) two stellar populations. This feature requires a two--step process, in which the nuclearly processed matter from a first generation (FG) of stars gives birth to a second generation (SG)…

This article is the second in a series in which we perform an extensive comparison of various galaxy-based cluster mass estimation techniques that utilise the positions, velocities and colours of galaxies. Our aim is to quantify the…

Most Galactic Globular Clusters (GCs) harbour multiple populations of stars (MPs), composed of at least two generations: the first characterized by a "standard" $\alpha$-enhanced metal mixture, as observed in field halo stars of the Milky…

We infer the ages of three young stellar clusters, NGC 2004, NGC 7419, and NGC 2100, using Stellar Ages, a statistical algorithm designed to infer stellar population properties from color magnitude diagrams. Recent studies have revealed…

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 focus on the sodium destruction in models reaching the high hot bottom burning temperatures needed to efficiently cycle oxygen to nitrogen in AGB models at the nominal [Fe/H] of the cluster NGC 2808. We increase the initial neon…

We investigate the Fe, C, N, O, Mg, Al, Si, K, Ca, Ce and Nd abundances of 2283 red giant stars in 31 globular clusters from high-resolution spectra observed in both the northern and southern hemisphere by the SDSS-IV APOGEE-2 survey. This…

The presence of star-to-star light-element abundance variations (a.k.a. multiple populations, MPs) appears to be ubiquitous within old and massive clusters in the Milky Way and all studied nearby galaxies. Most previous studies have…

An increasing number of photometric observations of multiple stellar populations in Galactic globular clusters is seriously challenging the paradigm of GCs hosting single, simple stellar populations. These multiple populations manifest…

The existence of star-to-star light-element abundance variations in massive Galactic and extragalactic star clusters has fairly recently superseded the traditional paradigm of individual clusters hosting stars with the same age, and uniform…

Galaxy clusters appear as extended sources in XMM-Newton images, but not all extended sources are clusters. So, their proper classification requires visual inspection with optical images, which is a slow process with biases that are almost…

Integrated-light star cluster catalogues in external galaxies are subject to complex, often poorly-characterised selection effects that can bias inferred cluster demographics and introduce significant uncertainties, limiting the physical…

Globular Clusters (GCs) have historically been subdivided in either two (disk/halo) or three (disk/inner-halo/outer-halo) groups based on their orbital, chemical and internal physical properties. The qualitative nature of this subdivision…

Cluster analysis is the distribution of objects into different groups or more precisely the partitioning of a data set into subsets (clusters) so that the data in subsets share some common trait according to some distance measure. Unlike…

In this study, we identified and characterized the hot and luminous UV-bright stars in the globular cluster NGC 2808. We combined data from the Ultra Violet Imaging Telescope (UVIT) on-board the Indian space satellite, AstroSat, with the…

Evidence that the multiple populations (MPs) are common properties of globular clusters (GCs) is accumulated over the past decades from clusters in the Milky Way and in its satellites. This finding has revived GC research, and suggested…