Related papers: Pre-mainsequence stellar evolution in N-body model…
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 study close encounters involving massive main sequence stars and the evolution of the exotic products of these encounters as common--envelope systems or possible hypernova progenitors. We show that parabolic encounters between low-- and…
We study the evolution and fate of solar composition supermassive stars in the mass range 60 - 1000 Msun. Our study is relevant both for very massive objects observed in young stellar complexes as well as supermassive stars that may…
Collisions were suggested to potentially play a role in the formation of massive stars in present day clusters, and have likely been relevant during the formation of massive stars and intermediate mass black holes within the first star…
We investigate the formation by accretion of massive primordial protostars in the range 10 to 300 Msun. The high accretion rate used in the models (4.4 x 10^{-3} Msun/yr) causes the structure and evolution to differ significantly from those…
We present a model for the formation of massive ($M > 10 M_\odot$) stars through accretion-induced collisions in the cores of embedded dense stellar clusters. This model circumvents the problem of accreting onto a star whose luminosity is…
We perform a large set of radiation hydrodynamics simulations of primordial star formation in a fully cosmological context. Our statistical sample of 100 First Stars show that the first generation of stars have a wide mass distribution…
We study the evolution of embedded clusters. The equations of motion of the stars in the cluster are solved by direct N-body integration while taking the effects of stellar evolution and the hydrodynamics of the natal gas content into…
Massive stars, by which we mean those stars exploding as core collapse supernovae, play a pivotal role in the evolution of the Universe. Therefore, the understanding of their evolution and explosion is fundamental in many branches of…
Luminosities of pre-main sequence stars evolve during the protoplanetary disc lifetime. This has a significant impact on the heating of their surrounding protoplanetary disks, the natal environments of planets. Moreover, stars of different…
We study the occurrence of physical collisions between stars in young and compact star cluster. The calculations are performed on the GRAPE-4 with the starlab software environment which include the dynamical evolution and the nuclear…
Core collapse of dense massive star clusters is unavoidable and this leads to the formation of massive objects, with a mass up to 1000 $\msun$ and even larger. When these objects become stars, stellar wind mass loss determines their…
[abridged] We have assembled a database of stars having both masses determined from measured orbital dynamics and sufficient spectral and photometric information for their placement on a theoretical HR diagram. Our sample consists of 115…
Nuclear star clusters (NSCs) surrounding supermassive black holes (SMBHs) are among the densest stellar environments in the universe. In these environments, collisions can shape the stellar mass function and produce exotic stellar…
Massive star clusters are often used as tracers of galaxy formation and assembly. In order to do so, we must understand their properties at formation, and how those properties change with time, galactic environment, and galaxy assembly…
In young dense clusters repeated collisions between massive stars may lead to the formation of a very massive star (above 100 Msun). In the past the study of the long-term evolution of merger remnants has mostly focussed on collisions…
We investigate the impact of pre-main sequence stellar luminosity evolution on the thermal and chemical properties of disc midplanes. We create template disc models exemplifying initial conditions for giant planet formation for a variety of…
Stars mostly form in groups consisting of a few dozen to several ten thousand members. For 30 years, theoretical models provide a basic concept of how such star clusters form and develop: they originate from the gas and dust of collapsing…
A supermassive black hole (SMBH) surrounded by a dense, nuclear star cluster resides at the center of many galaxies. In this dense environment, high-velocity collisions frequently occur between stars. About $10 \%$ of the stars within the…
We present new evolutionary models for zero-metallicity stars, covering a large range of initial masses (from 0.8 to 100 M_sun). Models are computed with overshooting from stellar cores and convective envelopes, and assuming mass-loss from…