Related papers: Exploring the impact of IMF and binary parameter s…
Because the majority of massive stars are born as members of close binary systems, populations of massive main-sequence stars contain stellar mergers and products of binary mass transfer. We simulate populations of massive stars accounting…
Stars stripped of their envelopes from interaction with a binary companion emit a significant fraction of their radiation as ionizing photons. They are potentially important stellar sources of ionizing radiation, however, they are still…
The mass of unresolved young star clusters derived from spectro-photometric data may well be off by a factor of 2 or more once the migration of massive stars driven by mass segregation is accounted for. We quantify this effect for a large…
We investigate how different stellar initial mass functions (IMFs) can affect the mass loss and survival of star clusters. We find that IMFs with radically different low-mass cut-offs (between 0.1 and 2 Msun) do not change cluster…
For synthesising star clusters and whole galaxies, stellar populations need to be modelled by a set of four functions that define their initial distribution of stellar masses and of the orbital properties of their binary-star populations.…
The initial mass function (IMF), binary fraction and distributions of binary parameters (mass ratios, separations and eccentricities) are indispensable input for simulations of stellar populations. It is often claimed that these are poorly…
The effects of stochasticity on the luminosities of stellar populations are an often neglected but crucial element for understanding populations in the low mass or low star formation rate regime. To address this issue, we present SLUG, a…
We study a sample of spectroscopic binaries (SBs) in the local solar neighbourhood to 100 pc and to an absolute magnitude of 4 in an attempt to find the distributions of the period, primary mass and the mass ratio as well as the IMF of the…
The stellar masses, mean ages, metallicities, and star formation histories of galaxies are now commonly estimated via stellar population synthesis (SPS) techniques. SPS relies on stellar evolution calculations from the main sequence to…
Star clusters are studied widely both as benchmarks for stellar evolution models and in their own right. Cluster age and mass distributions within galaxies are probes of star formation histories, and of cluster formation and disruption…
As the total mass of stellar populations of fixed IMF, age and metallicity tends to infinity, resulting intrinsic $M/L$ values quickly converge to fixed numbers associated to the particulars of the stars in question. When going to very…
The binary fraction of a stellar population can have pronounced effects on its properties, and in particular the number counts of different massive star types, and the relative subtype rates of the supernovae which end their lives. Here we…
We employ a large sample of 20171 optically-selected groups and clusters at 0.15 < z < 0.4 in the SDSS to investigate how the stacked stellar mass fraction varies across a wide range of total mass, $M_{500}$. Our study improves upon…
There is much debate on how high-mass star formation varies with environment, and whether the sparsest star-forming environments are capable of forming massive stars. To address this issue, we have observed eight apparently isolated OB…
In a probabilistic framework of the interpretation of the initial mass function (IMF), the IMF cannot be arbitrarily normalized to the total mass, M, or number of stars, N, of the system. Hence, the inference of M and N when partial…
We present a new study of H{\alpha}/FUV flux ratios of star forming regions within a sample of nearby spiral galaxies. We search for evidence of the existence of a cluster mass dependent truncation in the underlying stellar initial mass…
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…
We first give a short historical overview with some key facts of massive star population synthesis with binaries. We then discuss binary population codes and focus on two ingredients which are important for massive star population synthesis…
Does the IMF vary? Is it significantly different in metal-rich environments than in metal-poor ones? Theoretical work predicts this to be the case. But in order to provide robust empirical evidence for this, the researcher must understand…
We undertake a systematic analysis of the early (< 0.5 Myr) evolution of clustering and the stellar initial mass function in turbulent fragmentation simulations. These large scale simulations for the first time offer the opportunity for a…