Related papers: Which Globular Clusters contain Intermediate-mass …
We study the formation of massive black holes in the first star clusters. We first locate star-forming gas clouds in proto-galactic haloes of $\gtrsim \!10^7\,{\rm M}_{\odot}$ in cosmological hydrodynamics simulations and use them to…
Intermediate-mass black holes (IMBHs) are of interest in a wide range of astrophysical fields. In particular, the possibility of finding them at the centers of globular clusters has recently drawn attention. IMBHs became detectable since…
Recent observations of globular clusters (GCs) provide evidence that the stellar initial mass function (IMF) may not be universal, suggesting specifically that the IMF grows increasingly top-heavy with decreasing metallicity and increasing…
We present results of a series of Monte Carlo simulations investigating the imprint of a central intermediate-mass black hole (IMBH) on the structure of a globular cluster. We investigate the three-dimensional and projected density…
The origin of supermassive black holes (SMBH) in galaxy centers still remains uncertain. There are two possible ways of their formation - from massive ($10^5 - 10^6 M_{\odot}$) and low-mass ($100 M_{\odot}$) BH nuclei. The latter scenario…
Intermediate mass black holes (IMBHs) have masses between the $10^2\!-\!10^6$ M$_\odot$ and are key to our understanding of the formation of massive black holes. The known population of IMBH remains small, with a few hundred candidates and…
We compare the results of a large grid of N-body simulations with the surface brightness and velocity dispersion profiles of the globular clusters $\omega$ Cen and NGC 6624. Our models include clusters with varying stellar-mass black hole…
Recently, both stellar mass-segregation and binary-fractions were uniformly measured on relatively large samples of Galactic Globular Clusters (GCs). Simulations show that both sizeable binary-star populations and Intermediate-Mass Black…
The different methods of determination of black holes (BHs) masses are presented for three classes of BHs observed in the Universe: stellar mass BHs, intermediate mass BHs (IMBHs) and supermassive BHs (SBHs). The results of these…
Intermediate Mass Black Holes (IMBHs; 10^1.3-5 M_sun) are thought to form as relics of Population III stars or from the runaway collapse of stars in young clusters; their number and very existence are uncertain. We ran N-body simulations of…
Accreting intermediate-mass black holes (IMBHs) have been proposed as an explanation for ultraluminous X-ray sources (ULXs). Runaway core collapse inside a massive cluster is a possible mechanism for IMBH formation. But if so, why are ULXs…
Black holes are usually observed to be of stellar-mass or supermassive. By natural extension, there should be a population of Intermediate-Mass Black Holes (IMBHs: with mass between $100$ to $10^6 M_{\odot}$) in the Universe; which has…
The most massive galaxies in the Universe also host the largest supermassive black holes (SMBHs), with masses of $10^9 \: \mathrm{M_{\odot}}$ and above. During their hierarchical assembly, these galaxies have experienced only a few major…
Intermediate-mass black holes (IMBHs), with masses in the range $100-10^{6}$ M$_{\odot}$, are the link between stellar-mass BHs and supermassive BHs (SMBHs). They are thought to be the seeds from which SMBHs grow, which would explain the…
Surface brightness profiles of globular clusters with shallow central cusps (Sigma ~ R^v with -0.3<~ v <~ -0.05) have been associated by several recent studies with the presence of a central intermediate mass black hole (IMBH). Such shallow…
We investigate the formation of intermediate mass black holes (IMBHs) through hierarchical mergers of stellar origin black holes (BHs), as well as BH mergers formed dynamically in nuclear star clusters. Using a semi-analytical approach…
Globular clusters are an excellent laboratory for stellar population and dynamical research. Recent studies have shown that these stellar systems are not as simple as previously assumed. With multiple stellar populations as well as outer…
For a sample of nine Galactic globular clusters we measured the inner kinematic profiles with integral-field spectroscopy that we combined with existing outer kinematic measurements and HST luminosity profiles. With this information we are…
We have determined the masses and mass-to-light ratios of 50 Galactic globular clusters by comparing their velocity dispersion and surface brightness profiles against a large grid of 900 N-body simulations of star clusters of varying…
Globular clusters should be born with significant numbers of stellar-mass black holes (BHs). It has been thought for two decades that very few of these BHs could be retained through the cluster lifetime. With masses ~10 MSun, BHs are ~20…