Related papers: X-ray binaries powered by massive stellar black ho…
We analyze the mass distribution of stellar black holes derived from the light and radial velocity curves of optical stars in close binary systems using dynamical methods. The systematic errors inherent in this approach are discussed. These…
We study the origin of the ultraluminous X-ray source M82-X1 in the nearby starburst galaxy M82. This X-ray source is of particular interest as it is currently the best candidate intermediate mass black hole; it is associated with a 54mHz…
In a star cluster with a sufficiently large escape velocity, black holes (BHs) that are produced by BH mergers can be retained, dynamically form new BH binaries, and merge again. This process can repeat several times and lead to significant…
We combine Hubble Space Telescope images from the Great Observatories Origins Deep Survey with archival Very Large Telescope and Keck spectra of a sample of 11 X-ray selected broad-line active galactic nuclei in the redshift range 1<z<2 to…
The recent discovery of high-redshift (z > 6) supermassive black holes (SMBH) favors the formation of massive seed BHs in protogalaxies. One possible scenario is formation of massive stars ~ 1e3-1e4 Msun via runaway stellar collisions in a…
Stellar-mass black holes are the final remnants of stars born with more than 15 solar masses. Billions are expected to reside in the Local Group, yet only few are known, mostly detected through X-rays emitted as they accrete material from a…
Young star clusters are dynamically active stellar systems and are a common birthplace for massive stars. Low-mass star clusters ($\sim{}300-10^3$ M$_\odot$) are more numerous than massive systems and are characterized by a two-body…
Liu et al. (2019) recently reported the detection of a 68 [+11/-13] solar mass (Msun) black hole (BH) paired with an 8.2 [+0.9/-1.2] Msun B-type sub-giant star in the 78.9-day spectroscopic binary system LB-1. Such a black hole is over…
We study a sample of $\sim$50,000 dwarf starburst and late-type galaxies drawn from the COSMOS survey with the aim of investigating the presence of nuclear accreting black holes (BHs) as those seed BHs from which supermassive BHs could grow…
In this paper, globular star clusters which contain a sub-system of stellar-mass black holes (BH) are investigated. This is done by considering two-component models, as these are the simplest approximation of more realistic multi-mass…
We perform MHD simulations in full GR of uniformly rotating stars that are marginally unstable to collapse. Our simulations model the direct collapse of supermassive stars (SMSs) to seed black holes (BHs) that can grow to become the…
We show that a common evolutionary history can produce the black hole binaries in the Galaxy in which the black holes have masses of ~ 5-10 M_sun. In with low-mass, <~ 2.5 M_sun, ZAMS (zero age main sequence) companions, the latter remain…
The early evolution of dense stellar systems is governed by massive single star and binary evolution. Core collapse of dense massive star clusters can lead to the formation of very massive objects through stellar collisions ($M\geq$ 1000…
The relation between the mass and spin of stellar-mass binary black holes (BBHs) has been proposed to be a smoking gun for the presence of multiple formation channels for compact objects. First-generation black holes (BHs) formed by…
In this study, we investigate the dynamics of Intermediate-Mass Black Hole (IMBH) binaries within Nuclear Star Clusters (NSCs) that contain a population of stellar-mass black holes (BHs). We examine how these stellar and BH populations…
The energy and momentum deposited by the radiation from accretion onto the supermassive black holes (BHs) that reside at the centres of virtually all galaxies can halt or even reverse gas inflow, providing a natural mechanism for…
In this paper, we address the question: What is the probability of stellar-mass black hole (BH) binaries co-existing in a globular cluster with an intermediate-mass black hole (IMBH)? Our results suggest that the detection of one or more BH…
Solar-mass black holes with masses in the range of $\sim 1-2.5 M_{\odot}$ are not expected from conventional stellar evolution, but can be produced naturally via neutron star (NS) implosions induced by capture of small primordial black…
Supermassive black holes (BHs) and their host galaxies are interlinked by virtue of feedbacks and are thought to be co-eval across the Hubble time. This relation is highlighted by an approximate proportionality between the BH mass…
Today's sensitive, high-resolution X-ray observations allow the study of populations of X-ray sources, in the luminosity range of Galactic X-ray binaries, in galaxies as distant as 20-30 Mpc. The traditional astronomical tools of…