Related papers: Intermediate-Mass Black Holes
This article documents our ongoing search for the elusive "intermediate-mass" black holes. These would bridge the gap between the approximately ten solar mass "stellar-mass" black holes that are the end-product of the life of a massive…
Black holes with hundreds to thousands of solar masses are more massive than can be formed from a single star in the current universe, yet the best candidates for these objects are not located in gas-rich environments where gradual…
A discussion of the entropy of the universe leads to the suggestion of very many intermediate-mass black holes between thirty and three hundred thousand solar masses in the halo. It is consistent with observations on wide binaries as well…
This paper reviews the subject of intermediate-mass black holes (IMBHs) with masses between those of "stellar-mass" and "super-massive" black holes. The existence of IMBHs is a real possibility: they might plausibly have formed as remnants…
There is a lot of current astrophysical evidence and interest in intermediate mass black holes, ranging from a few hundred to several thousand solar masses. The active galaxy M82 and the globular cluster in M31, for example, are known to…
Astronomers have discovered two populations of black holes: (i) stellar-mass black holes with masses in the range 5 to 30 solar masses, millions of which are present in each galaxy in the universe, and (ii) supermassive black holes with…
Stellar-mass black holes ($3$ $M_\odot \lesssim M_{\rm BH} \lesssim 150$ $M_\odot$) are the natural product of the evolution of heavy stars ($M_{\rm star} \gtrsim 20$ $M_\odot$). In our Galaxy, we expect $10^8$-$10^9$ stellar-mass black…
Observational searches for Intermediate Mass Black Holes (IMBHs), defined to have masses between 30 and 300,000 solar masses, provide limits which allow up to ten percent of what is presently identified as halo dark matter to be in the form…
Black holes are fascinating objects. As a class of solutions to the Einstein equations they have been studied a great deal, yielding a wealth of theoretical results. But do they really exist? What do astronomers really mean when they claim…
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) are an (as yet) elusive class of black holes that are expected to lie in the $10^2-10^5\,M_{\odot}$ range, between the firmly established stellar-mass black holes and ${\gtrsim}10^6\,M_{\odot}$…
Recent high-resolution X-ray imaging studies have discovered possible candidates of intermediate-mass black holes with masses of $M_\bullet \sim 10^{2-4} \MO$ in circumnuclear regions of many (disk) galaxies. It is known that a large number…
While until recently they were often considered as exotic objects of dubious existence, in the last decades there have been overwhelming observational evidences for the presence of stellar mass black holes in binary systems, supermassive…
Black holes (BHs) with masses between 100 to 100,000 times the mass of the Sun ($\rm{M}_{\odot}$) are classified as intermediate-mass black holes (IMBHs), potentially representing a crucial link between stellar-mass and supermassive BHs.…
Observational searches for Intermediate-Mass Black Holes (IMBHs), defined to have masses between 30 and 300,000 solar masses, provide limits which allow up to ten percent of what is presently identified as halo dark matter to be in the form…
In this small review we present the actual state the knowledge about weighting black holes. Black holes can be found in stellar binary systems in our Galaxy and in other nearby galaxies, in globular clusters, which we can see in our and…
While large numbers of supermassive black holes have been detected at z>6, their origin is still essentially unclear. Numerical simulations have shown that the conditions for the classical direct collapse scenario are very restrictive and…
The existence of supermassive black holes lurking in the centers of galaxies and of stellar binary systems containing a black hole with a few solar masses has been established beyond reasonable doubt. The idea that black holes of…
In many theoretical scenarios it is expected that intermediate-mass black holes (IMBHs, with masses M ~ 100-10000 solar masses) reside at the centers of some globular clusters. However, observational evidence for their existence is limited.…
We demonstrate that cosmic string loops may provide a joint resolution of two mysteries surrounding recently observed black holes. For a string tension in an appropriate range, large radius string loops have the potential to provide the…