Related papers: The minimum stellar metallicity observable in the …
The formation of the first stars out of metal-free gas appears to result in stars at least an order of magnitude more massive than in the present-day case. We here consider what controls the transition from a primordial to a modern initial…
Metals enhance the cooling efficiency of molecular clouds, promoting fragmentation. Consequently, increasing the metallicity may boost the formation of low-mass stars. Within the integrated galaxy initial mass function (IGIMF) theory, this…
An essential component of galaxy formation theory is the stellar initial mass function (IMF), that describes the parent distribution of stellar mass in star forming regions. We present observational evidence in a sample of early-type…
The Initial Mass Function (IMF) of early-type galaxies (ETGs) has been found to feature systematic variations by both dynamical and spectroscopic studies. In particular, spectral line strengths, based on gravity-sensitive features, suggest…
We review recent 3D cosmological hydrodynamic simulations of primordial star formation from cosmological initial conditions (Pop III.1) and from initial conditions that have been altered by radiative feedback from stellar sources (Pop…
The first stars fundamentally transformed the early universe by emitting the first light and by producing the first heavy elements. These effects were predetermined by the mass distribution of the first stars, which is thought to have been…
The most metal-poor stars in dwarf spheroidal galaxies (dSphs) can show the nucleosynthetic patterns of one or a few supernovae. These supernovae could have zero metallicity, making metal-poor dSph stars the closest surviving links to…
Stars formed in galaxy cluster potential wells must be responsible for the high level of enrichment measured in the intracluster medium (ICM); however, there is increasing tension between this truism and the parsimonious assumption that the…
We investigate the conditions under which the first low-mass stars formed in the universe by confronting theoretical predictions governing the transition from massive Population III to low-mass Population II stars with recent observational…
When star clusters are formed at low star-formation rates (SFRs), their stellar initial mass function (IMF) can hardly be filled continuously with stars at each mass. This lack holds for massive stars and is observationally verified by the…
We review recent advances in our understanding of the origin of the initial mass function (IMF). We emphasize the use of numerical simulations to investigate how each physical process involved in star formation affects the resulting IMF. We…
We explore the assumption, widely used in many astrophysical calculations, that the stellar initial mass function (IMF) is universal across all galaxies. By considering both a canonical Salpeter-like IMF and a non-universal IMF, we are able…
We investigate the origin of a bottom-heavy stellar initial mass function (IMF) recently observed in elliptical galaxies by using chemical evolution models with a non-universal IMF. We adopt the Kroupa IMF with the three slopes (alpha_1,…
Small stellar systems like dwarf galaxies are suggested to be the main building blocks of our Galaxy by numerical simulations in Lambda CDM models. The existence of star streams like Sagittarius tidal stream indicates that dwarf galaxies…
Elements heavier than hydrogen and helium, collectively termed metals, were created inside stars and dispersed through space at the final stages of stellar evolution. The relative amounts of different isotopes (variants of the same element…
We investigate the mass-metallicity relations for the gaseous (MZRgas) and stellar components (MZRstar) of local star-forming galaxies based on a representative sample from SDSS DR12. The mass-weighted average stellar metallicities are…
Observational evidence has suggested the possibility of a Galactic halo which is dominated by white dwarfs (WDs). While debate continues concerning the interpretation of this evidence, it is clear that an initial mass function (IMF) biased…
Stellar chemical element ratios have well-defined systematic trends as a function of abundance, with an excellent correlation of these trends with stellar populations defined kinematically. This is remarkable, and has significant…
The metal-weak tail of the metallicity distribution function (MDF) of the Galactic Halo stars contains crucial information on the formation mode of the first generation of stars. To determine this observationally, it is necessary to observe…
In the last decade, the available measurements of fluorine abundance have increased significantly, providing additional information on the chemical evolution of our Galaxy and details on complex stellar nucleosynthesis processes. However,…