Related papers: Gravothermal oscillations in multi-component model…
Recent work suggested that the variation of the initial mass function (IMF) of stars depends on the physical conditions, notably, the metallicity and gas density. We investigated the properties of two clusters, namely the main cluster (MC)…
Recent studies suggest that the initial mass function (IMF) of the first stars was likely to be extremely top-heavy, unlike what is observed at present. We propose a scenario to generate fragmentation to lower masses once the first massive…
A stochastic model of fragmentation of molecular clouds has been developed for studying the resulting Initial Mass Function (IMF) where the number of fragments, inter-occurrence time of fragmentation, masses and velocities of the fragments…
In the context of the star formation through the fragmentation of an extremely metal-deficient protogalactic cloud, the gravitational collapse of filamentary gas clouds is explored with H$_2$ and HD chemistry. It is found by 1D…
We present a method for investigating variations in the upper end of the stellar Initial Mass Function (IMF) by probing the production rate of ionizing photons in unresolved, compact star clusters with ages <~10 Myr and with different…
The dichotomy between a universal mass function (IMF) and a variable IMF which depends on local physical parameters characterises observational and theoretical stellar astronomy. In this contribution the available distributions of…
We present new observations of the nuclear star cluster in the central parsec of the Galaxy with the adaptive optics assisted, integral field spectrograph SINFONI on the ESO/VLT. Our work allows the spectroscopic detection of early and late…
The universality or non-universality of the initial mass function (IMF) has significant implications for determining star formation rates and star formation histories from photometric properties of stellar populations. We reexamine whether…
Theoretical arguments and indirect observational evidence suggest that the stellar initial mass function (IMF) may evolve with time, such that it is more weighted toward high mass stars at higher redshift. Here we test this idea by…
We review current theories for the origin of the Stellar Initial Mass Function (IMF) with particular focus on the extent to which the IMF can be considered universal across various environments. To place the issue in an observational…
(Abridged) Accurate luminosity functions (LF) for a dozen globular clusters have now been measured at or just beyond their half-light radius using HST. They span almost the entire cluster main sequence below ~ 0.75 Msolar. All these…
The universality of the stellar initial mass function (IMF) is tested using Bayesian statistics with a sample of eight young Galactic stellar clusters (IC 348, ONC, NGC 2024, NGC 6611, NGC 2264, $\rho$ Ophiuchi, Chameleon I, and Taurus). We…
The earliest phases of clustered star formation and the origin of the stellar initial mass function (IMF) are currently much debated. In order to constrain the origin of the IMF, we investigated the internal and relative motions of starless…
Some theories of star formation suggest massive stars may only form in clustered environments, which would create a deficit of massive stars in low density environments. Observationally, Massey (2002) finds such a deficit in samples of the…
We present numerical investigations into the formation of massive stars from centrally condensed turbulent cores. The results of five hydrodynamical simulations are described, following the collapse of the core, fragmentation and the…
The discovery of EUV and soft X-ray excess emission in clusters of galaxies (the cluster soft-excess phenomenon) challenged the notion of the hot ($\sim 10^{7-8}$ K) gas as the only dominant thermal component of the intracluster medium…
Recent observations of globular clusters (GCs) provide evidence that the stellar initial mass function (IMF) may not be universal, suggesting specifically that the IMF grows increasingly top-heavy with decreasing metallicity and increasing…
Chemical and photometric models of elliptical galaxies with infall of primordial gas, and subsequent ejection of processed material via galactic winds, are described. Ensuring that these models are consistent with the present-day…
We present new GRIFFIN project hydrodynamical simulations that model the formation of galactic star cluster populations in low-metallicity ($Z=0.00021$) dwarf galaxies, including radiation, supernova and stellar wind feedback of individual…
Our understanding of stellar systems depends on the adopted interpretation of the IMF, phi(m). Unfortunately, there is not a common interpretation of the IMF, which leads to different methodologies and diverging analysis of observational…