Related papers: Collisions and close encounters involving massive …
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…
The high stellar densities in young compact star clusters, such as the star cluster R 136 in the 30 Doradus region, may lead to a large number of stellar collisions. Such collisions were recently found to be much more frequent than previous…
We present a new study of the collisional runaway scenario to form an intermediate-mass black hole (IMBH, MBH > 100 Msun) at the centre of a young, compact stellar cluster. The first phase is the formation of a very dense central core of…
In their final stages before undergoing a core-collapse supernova, massive stars may experience mergers between internal shells where carbon (C) and oxygen (O) are consumed as fuels for nuclear burning. This interaction, known as a C-O…
The current generation of millimeter interferometers have revealed a population of compact (r <~ 0.1 pc), massive (M ~ 100 Msun) gas cores that are the likely progenitors of massive stars. I review models for the evolution of these objects…
We use numerical simulations to examine the structure of merger remnants resulting from collisions of gas-rich spiral galaxies. When the gas fraction of the progenitors is small, the remnants structurally and kinematically resemble…
Mergers between stellar-mass black holes will be key sources of gravitational radiation for ground-based detectors. However, the rates of these events are highly uncertain, given that such systems are invisible. One formation scenario…
Approximately two hundred supermassive black holes (SMBHs) have been discovered within the first $\sim$Gyr after the Big Bang. One pathway for the formation of SMBHs is through the collapse of supermassive stars (SMSs). A possible obstacle…
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…
We study the complete merger of two massive stars inside a common envelope and the subsequent evolution of the merger product, a rapidly rotating massive supergiant. Three qualitatively different types of mergers have been identified and…
Several lines of evidence suggest that as dark matter haloes grow their scale radius increases, and that the density in their central region drops. Major mergers seem an obvious mechanism to explain both these phenomena, and the resulting…
We provide a set of analytic fits to the radii of pre-mainsequence stars in the mass range 0.1 < M/Msun < 8.0. We incorporate the formulae in N-body cluster models for evolution from the beginning of pre-main sequence. In models with 1,000…
Both simulations and observations indicate that stars form in filamentary, hierarchically clustered associations, most of which disperse into their galactic field once feedback destroys their parent clouds. However, during their early…
Modeling the evolution of progenitors of gravitational-wave merger events in binary stars faces two major uncertainties: the common-envelope phase and supernova kicks. These two processes are critical for the final orbital configuration of…
Star clusters can interact and merge in galactic discs, halos, or centers. We present direct N-body simulations of binary mergers of star clusters with $M_{\star} = 2.7 \times 10^4 \: \mathrm{M_{\odot}}$ each, using the N-body code BIFROST…
Close encounters between stars in star forming regions are important as they can perturb or destroy protoplanetary discs, young planetary systems, and stellar multiple systems. We simulate simple, viralised, equal-mass $N$-body star…
We investigate the fraction of close pairs and morphologically identified mergers on and above the star-forming main sequence (MS) at 0.2$\leq z\leq$2.0. The novelty of our work lies in the use of a non-parametric morphological…
Galaxy mergers trigger both star formation and accretion onto the central supermassive black hole. As a result of subsequent energetic feedback processes, it has long been proposed that star formation may be promptly extinguished in galaxy…
Hierarchical structure formation theory is based on the notion that mergers drive galaxy evolution, so a considerable framework of semi-analytic models and N-body simulations has been constructed to calculate how mergers transform a growing…
The recent detection of GW190521 stimulated ideas on how to populate the predicted black hole pair-instability mass gap. One proposed scenario is the dynamical merger of two stars below the pair instability regime forming a star with a…