Related papers: Intermediate-Mass Black Holes
Supermassive black holes appear to be uniquely associated with galactic bulges. The mean ratio of black hole mass to bulge mass was until recently very uncertain, with ground based, stellar kinematical data giving a value roughly an order…
There is currently much interest in the possible presence of intermediate-mass black holes in the cores of globular clusters. Based on theoretical arguments and simulation results it has previously been suggested that a large core radius --…
Ultra-luminous X-ray sources are extragalactic objects located outside the nucleus of the host galaxy with bolometric luminosities >10^39 erg s^-1. These extreme luminosities - if the emission is isotropic and below the theoretical (i.e.…
Supermassive black holes with masses of millions to billions of solar masses are commonly found in the centers of galaxies. Astronomers seek to image jet formation using radio interferometry, but still suffer from insufficient angular…
Recent observations suggest the presence of supermassive black holes at the centers of many galaxies. The existence of intermediate-mass black holes (IMBHs) in globular clusters has also been predicted. We focus on gravitational lensing as…
We perform fully relativistic simulations of the head-on collisions between intermediate-mass black holes and very massive stars. Such collisions are expected to occur in dense stellar clusters and may play an important role in growing the…
Could there be a large population of intermediate-mass black holes (IMBHs) formed in the early universe? Whether primordial or formed in Population III, these are likely to be very subdominant compared to the dark matter density, but could…
We discuss the method, and potential systematic effects therein, used for measuring the mass of stellar-mass black holes in X-ray binaries. We restrict our discussion to the method that relies on the validity of Kepler's laws; we refer to…
Black-hole masses of distant quasars cannot be measured directly, but can be estimated to within a factor 3 to 5 using scaling relationships involving the quasar luminosity and broad-line width. Why such relationships are reasonable is…
While no gravitational-wave detection of subsolar mass black holes has been confirmed to date, a number of candidate detections invite us to speculate on the origin of such black holes should a detection be confirmed. It is generally…
In this note we suggest that high-mass black holes; i.e., black holes of several solar masses, can be formed in binaries with low-mass main-sequence companions, provided that the hydrogen envelope of the massive star is removed in common…
The existence of massive black holes was postulated in the sixties, when the first quasars were discovered. In the late nineties their reality was proven beyond doubt, in the Milky way and a handful nearby galaxies. Since then, enormous…
A small group of X-ray binaries currently provides the best evidence for the existence of stellar-mass black holes. These objects are interacting binary systems where the X-rays arise from accretion of material onto a compact object (i.e.…
Establishing or ruling out, either through solid mass measurements or upper limits, the presence of intermediate-mass black holes (IMBHs) at the centers of star clusters would profoundly impact our understanding of problems ranging from the…
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…
We explore the potential cumulative energy production of stellar mass black holes in early galaxies. Stellar mass black holes may accrete substantially from the higher density interstellar media of primordial galaxies, and their energy…
Supernova theory suggests that black holes of a stellar origin cannot attain masses in the range of 50-135 solar masses in isolation. We argue here that this mass gap is filled in by black holes that grow by gas accretion in dense stellar…
It is widely accepted that black holes (BHs) with masses greater than a million solar masses (Msun) lurk at the centres of massive galaxies. The origins of such `supermassive' black holes (SMBHs) remain unknown (Djorgovski et al. 1999),…
Black hole is called optimal if information content is minimal at the University region, consisting of usual substance and one(n) black hole(s). Optimal black hole mass does not depend on the mass of the Universe region. Optimal black holes…
In the local universe, black hole masses have been inferred from the observed increase in the velocities of stars at the centres of their host galaxies. So far, masses of supermassive black holes in the early universe have only been…