Related papers: Towards Multiple-Star Population Synthesis
Since the early 1970s, stellar population modelling has been one of the basic tools for understanding the physics of unresolved systems from observation of their integrated light. Models allow us to relate the integrated spectra (or…
Two main models coexist for the environment in which stars form. The clustered model stipulates that the bulk of star formation occurs within dense embedded clusters, but only a minority of them survive the residual gas expulsion phase…
Data on the multiplicity of F- and G-type dwarf stars within 67pc of the Sun are presented. This distance-limited sample based on the Hipparcos catalog contains 4847 primary stars (targets) with 0.5<V-I_C<0.8 and is >90% complete. There are…
Stellar clusters are critical constituents within galaxies: they are the result of highest-density star formation, and through their spatially and temporally correlated feedback they regulate their host galaxy evolution. We present a novel…
We present a method to determine the star formation history of a mixed stellar population from its photometry. We perform a chi-squared minimization between the observed photometric distribution and a model photometric distribution, based…
Most stars do not form in isolation but as part of a cluster comprising anywhere between a few dozen to several million stars with stellar densities ranging from 0.01 to several 10$^5$ \Msun pc$^{-3}$. The majority of these clusters…
We have formed ``composite spectra'' by combining the integrated-light spectra of individual galaxies in 8 intermediate-redshift and 12 low-redshift clusters of galaxies. Because these composite spectra have much higher signal-to-noise…
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star-to-star light-element abundance variations in massive Galactic and extragalactic star clusters has fairly recently superseded the traditional paradigm of individual clusters hosting stars with the same age, and uniform…
The study of satellite galaxies can provide information on the merging and aggregation processes which, according to the hierarchical clustering models, form the larger spiral galaxies we observe. With the aim of testing hierarchical models…
Since the Hipparcos mission and recent large scale surveys in the optical and the near-infrared, new constraints have been obtained on the structure and evolution history of the Milky Way. The population synthesis approach is a useful tool…
When calculating IMFs for young clusters, one has to take into account that (a) most massive stars are born in multiple systems (b) most IMFs are derived from data that cannot resolve such systems, and (c) multiple chance superpositions…
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 describe statistical methods for measuring the exoplanet multiplicity function - the fraction of host stars containing a given number of planets - from transit and radial-velocity surveys. The analysis is based on the approximation of…
Galactic open clusters provide an abundant sample of stellar aggregates of various sizes, ages and metal abundances, apt to constitute a template for comparison with star systems in other galaxies. In this paper we present and discuss a…
We investigate sulphur abundance in 74 Galactic stars by using high resolution spectra obtained at ESO VLT and NTT telescopes. For the first time the abundances are derived, where possible, from three optical multiplets: Mult. 1, 6, and 8.…
Almost half of the stellar systems in the solar neighborhood are made up of multiple stars. In multiple-star systems, planet formation is under the dynamical influence of stellar companions, and the planet occurrence rate is expected to be…
The formation of stars above about twenty solar masses and their apparently high multiplicity remain heavily debated subjects in astrophysics. We have performed a vast high-resolution radial velocity spectroscopic survey of about 250 O- and…
In the massive globular cluster NGC 2808, RGB stars form at least five distinct groups in the so-called chromosome map photometric plane, arguably corresponding to different stellar populations. While a human expert can separate the groups…
We use evolutionary calculations presented in a recent paper (Cassisi et al. 1998) to predict B,V,I magnitudes for stars in galactic globulars. The effect of the adopted mixing length on stellar magnitudes and colors is discussed, showing…
The multiplicity function (MF) of groups and clusters of galaxies is determined using galaxy catalogues extracted from a set of Digitized Palomar Sky Survey (DPOSS) plates. The two different types of structures (of low and high richness)…