Related papers: Stellar Collisions and Black Hole Formation in Den…
In the cores of young dense star clusters repeated stellar collisions involving the same object can occur, which has been suggested to lead to the formation of an intermediate-mass black hole. In order to verify this scenario we compute the…
The evolution of young compact star clusters is studied using N-body simulations in which both stellar evolution and physical collisions between stars are taken into account. The initial conditions are chosen to represent R136, a compact…
We study the circumstances under which first collisions occur in young and dense star clusters. The initial conditions for our direct $N$-body simulations are chosen such that the clusters experience core collapse within a few million…
In this review, I present the case for how massive stars may form through stellar collisions. This mechanism requires very high stellar densities, up to 4 orders of magnitude higher than are observed in the cores of dense young clusters. In…
We study the early dynamical evolution of young, dense star clusters using Monte Carlo simulations for systems with up to N~10^7 stars. Rapid mass segregation of massive main-sequence stars and the development of the Spitzer instability can…
Rapid formation of supermassive black holes occurs in dense nuclear star clusters that are initially gas-dominated. Stellar-mass black hole remnants of the most massive cluster sink into the core, where a massive runaway black hole forms as…
Recent theoretical work has solidified the viability of the collisional runaway scenario in young dense star clusters for the formation of very massive stars (VMSs), which may be precursors to intermediate-mass black holes (IMBHs). We…
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…
Context. We present simulations of a massive young star cluster using \textsc{Nbody6++GPU} and \textsc{MOCCA}. The cluster is initially more compact than previously published models, with one million stars, a total mass of $5.86 \times…
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…
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…
Dense star clusters are promising nurseries for the formation and growth of intermediate-mass black holes (IMBHs; $\sim 10^2-10^5\,\mathrm{M}_{\odot}$), with increasing observational evidence pointing to their presence in massive star…
The early evolution of dense stellar systems is governed by massive single star and binary evolution. Core collapse of dense massive star clusters can lead to the formation of very massive objects through stellar collisions ($M\geq$ 1000…
The evolution of dense star clusters is followed by direct high-accuracy N-body simulation. The problem is to first order a gravitational N-body problem, but stars evolve due to astrophysics and the more massive ones form black holes or…
We apply the idea that dense stellar systems in the central region of galaxies are formed via globular cluster mergers to the formation of the nuclear star cluster of the Milky Way, where a massive black hole is present. Our high precision…
Globular clusters were thought to be simple stellar populations, but recent photometric and spectroscopic evidence suggests that the clusters' early formation history was more complicated. In particular, clusters show star-to-star abundance…
We consider nearby young black holes formed after supernova explosions in close binaries whose secondary components are currently observed as the so-called runaway stars. Using data on runaway stars and making reasonable assumptions about…
Recent observations indicate that the progenitors of globular clusters (GCs) at high redshifts had high average stellar surface densities above $10^5\, \mathrm{M}_\odot\, \mathrm{pc}^{-2}$. The internal structure and kinematics of the…
Following the discovery of a black hole (BH) with a mass of 10^3-10^6 M(sun) in a starburst galaxy M82, we study formation of such a BH via successive merging of stellar-mass BHs within a star cluster. The merging has a runaway…
Massive stellar clumps in high redshift galaxies interact and migrate to the center to form a bulge and exponential disk in <1 Gyr. Here we consider the fate of intermediate mass black holes (BHs) that might form by massive-star coalescence…