Related papers: Predicting intermediate-mass black hole formation …
Intermediate-mass black holes (IMBHs) may provide the missing link to understanding the growth of supermassive black holes in the early Universe. Some formation scenarios predict that IMBHs could have formed by runaway collisions in…
We study the long term dynamical evolution of stellar mass black holes (BHs) at the Galactic center (GC) and put constraints on their number and central mass distribution. Models of the GC are considered that have not yet achieved a steady…
Supermassive black holes are prevalent at the centers of massive galaxies, and their masses scale with galaxy properties, increasing evidence suggesting that these trends continue to low stellar masses. Seeds are needed for supermassive…
The processes that govern the formation of intermediate-mass black holes (IMBHs) in dense stellar clusters are still unclear. Here, we discuss the role of stellar mergers, star-BH interactions and accretion, as well as BH binary (BBH)…
We study the stellar dynamics of the first star clusters after intermediate-mass black holes (IMBHs) are formed via runaway stellar collisions. We use the outputs of cosmological simulations of Sakurai et al. (2017) to follow the star…
We present a novel framework to infer the mass of clusters that host hierarchical binary black hole (BBH) mergers detected with gravitational-waves (GWs), on a single event basis. We show that the requirement that a second-generation (2G)…
The centres of galaxies host nuclear stellar clusters, supermassive black holes, or both. The origin of this dichotomy is still a mystery. Nuclear stellar clusters are the densest stellar system in the Universe, so they are ideal places for…
Globular star clusters contain thousands to millions of old stars packed within a region only tens of light years across. Their high stellar densities make it very probable that their member stars will interact or collide. There has been…
Nantais et al. used the Hubble Space Telescope to localize probable globular clusters (GCs) in M81, a spiral galaxy at a distance of 3.63 Mpc. Theory predicts that GCs can host intermediate-mass black holes (IMBHs) with masses M_BH \sim 100…
Supermassive black holes (SMBHs) are found in most galactic nuclei. A significant fraction of these nuclei also contain a nuclear stellar cluster (NSC) surrounding the SMBH. In this paper, we consider the idea that the NSC forms first, from…
Recent numerical simulations of the fragmentation of primordial molecular clouds in hierarchical cosmogonies have suggested that the very first stars (the so-called Population III) may have been rather massive. Here we point out that a…
We use semi-analytic models implemented in the Millennium Simulation to analyze the merging histories of dark matter haloes and of the galaxies that reside in them. We assume that supermassive black holes only exist in galaxies that have…
Theoretical models predict that intermediate-mass black holes (IMBHs) exist in globular clusters (GCs), but observational evidence remains elusive. Millisecond pulsars (MSPs), which are abundant in GCs and have served as precise probes for…
We make a case for the existence for ultra-massive black holes (UMBHs) in the Universe, but argue that there exists a likely upper limit to black hole masses of the order of $M \sim 10^{10} \msun$. We show that there are three strong lines…
Gravitational waves (GWs) offer an unprecedented opportunity to survey the sky and detect mergers of compact objects. While intermediate-mass black holes (IMBHs) have not been detected beyond any reasonable doubt with either dynamical or…
We simulate mergers between galaxies containing collisionally-relaxed nuclei around massive black holes (MBHs). Our galaxies contain four mass groups, representative of old stellar populations; a primary goal is to understand the…
Hierarchical mergers are one of the distinctive signatures of binary black hole (BBH) formation through dynamical evolution. Here, we present a fast semi-analytic approach to simulate hierarchical mergers in nuclear star clusters (NSCs),…
We present the mass--spin diagram for classifying black holes and studying their formation pathways providing an analogue to the Hertzsprung-Russell diagram. This allows for black hole evolutionary tracks as a function of redshift,…
Hundreds of stellar-mass black holes likely form in a typical globular star cluster, with all but one predicted to be ejected through dynamical interactions. Some observational support for this idea is provided by the lack of X-ray-emitting…
Determining the final result of black hole-neutron star mergers, and in particular the amount of matter remaining outside the black hole at late times and its properties, has been one of the main motivations behind the numerical simulation…