Related papers: Theories of the initial mass function
Understanding the processes that determine the stellar Initial Mass Function (IMF) is a critical unsolved problem, with profound implications for many areas of astrophysics. In molecular clouds, stars are formed in cores, gas condensations…
Planet formation models have been developed during the last years in order to try to reproduce the observations of both the solar system, and the extrasolar planets. Some of these models have partially succeeded, focussing however on…
We discuss possible mechanisms underlying the observed features of stellar activity cycles, such as multiple periodicities in very active stars, non-cyclic activity observed in moderately active stars, and spatial distribution of stellar…
I review some recent work on low-mass star formation, with an emphasis on theory, basic principles, and unresolved questions. Star formation is both a gravitational fragmentation problem as well as an accretion problem. Molecular cloud…
We explore the origin of the rotation rates of massive stars. Contrary to their low-mass siblings, most massive stars do not have detectable magnetic fields, so that star-disk interaction models used for the formation of rotating low-mass…
Massive stars influence their surroundings through radiation, winds, and supernova explosions far out of proportion to their small numbers. However, the physical processes that initiate and govern the birth of massive stars remain poorly…
The theoretical discription of a hot star interior is obtained. It explains the distribution of stars over their masses, mass-radius-temperature and mass-luminosity dependencies. The theory of the apsidal rotation of binary stars and the…
Understanding star formation is problematic as it originates in the large scale dynamics of a galaxy but occurs on the small scale of an individual star forming event. This paper presents the first numerical simulations to resolve the star…
The question whether or not the initial mass function is universal, i.e. the same in all kinds of environments, is of critical importance for the theory of star formation and still intensely debated. A top-heavy initial mass function may be…
The stellar initial mass function (IMF) of early-type galaxies is the combination of the IMF of the stellar population formed in-situ and that of accreted stellar populations. Using as an observable the effective IMF $\alpha_{IMF}$, defined…
Observations of both galaxies in the distant Universe and local starbursts are showing increasing evidence for very hard ionizing spectra that stellar population synthesis models struggle to reproduce. Here we explore the effects of the…
We have investigated the effect of initial mass segregation on the runaway merging of stars. The evolution of multi-mass, dense star clusters was followed by means of direct N-body simulations of up to 131.072 stars. All clusters started…
We review theoretical models of Population III.1 star formation, focusing on the protostellar feedback processes that are expected to terminate accretion and thus set the mass of these stars. We discuss how dark matter annihilation may…
The fundamental properties of stellar clusters, such as the age or the total initial mass in stars, are often inferred from population synthesis models. The predicted properties are then used to constrain the physical mechanisms involved in…
The initial mass function (IMF) is an important, yet enigmatic aspect of the star formation process. The two major open questions regarding the IMF are: is the IMF constant regardless of environment? Is the IMF a universal property of star…
Throughout the cosmic history, primordial black holes may experience an efficient phase of baryonic mass accretion from the surrounding medium. While the realm of accretion physics is marked by numerous uncertainties, and a comprehensive…
We present the first results of a study of the expected properties of the first stellar generations in the Universe. In particular, we consider and discuss a series of properties that, on the basis of the emission from associated HII…
We briefly describe the three existing scenarios for forming massive stars and emphasize that the arguments often used to reject the accretion scenario for massive stars are misleading. It is usually not accounted for the fact that the…
Star formation is intimately linked to the dynamical evolution of molecular clouds. Turbulent fragmentation determines where and when protostellar cores form, and how they contract and grow in mass via accretion from the surrounding cloud…
We suggest a model for star formation function and a model for dissipation of the turbulent energy of interstellar medium. Star formation function takes into account the effect of turbulization of the ISM. It is shown that application of…