Related papers: COSMOLOGICAL ORIGIN OF QUASARS
One of the most promising explanations for the origin of the billion solar mass black holes (BHs) inferred to power quasars at redshifts z > 6 is that supermassive stars (SMSs) with masses > 10,000 solar masses collapse to form the seed BHs…
The distribution on the sky of clusters of galaxies shows significant association with relatively nearby, large, active galaxies. The pattern is that of clusters paired equidistant across a central galaxy with the apparent magnitudes and…
I present an elementary primer of black hole physics, including its general relativity basis, all peppered with astrophysical illustrations. Following a brief review of the process stellar collapse to a black hole, I discuss the…
The recent discovery of a large number of massive black holes within the first two billion years after the Big Bang, as well as their peculiar properties, have been largely unexpected based on the extrapolation of the properties of luminous…
The observational evidence points to the origin of our Universe from a big-bang explosion, the normal matter we observed can be well explained by the particles created in the strong and weak interacting phases of the early universe. The…
The tight relationship between the masses of black holes and galaxy spheroids in nearby galaxies implies a causal connection between the growth of these two components. Optically luminous quasars host the most prodigious accreting black…
It is discussed how the ideas of entropy and the second law of thermodynamics, conceived long ago during the nineteenth century, underly why cosmological dark matter exists and originated in the first three years of the universe in the form…
We show that the mass function of black holes expected from the past quasar activity (both visible and obscured) is consistent with the number of dormant black holes found in the bulges of nearby galaxies. The joint formation of quasars and…
Blazars are Active Galactic Nuclei characterized by relativistic jets launched in the vicinity of the central engine (i.e. a supermassive black hole), that are oriented close to our line of sight. Their peculiar orientation makes them very…
In this paper we show that to explain the observed distribution of amplitudes in a large sample of quasar lightcurves, a significant contribution from microlensing is required. This implies the existence of a cosmologically distributed…
Primordial black holes (PBHs) could account for all or part of dark matter, as well as for some LIGO events. We discuss the spins of primordial black holes produced in different cosmological scenarios, with the emphasis on recently…
When black hole jets encounter ambient medium, they can compress the gas, trigger star formation, and create stellar clusters containing tens of thousands of stars. Here, we report a remarkable discovery of such a phenomenon that happened…
Quasars are galaxies hosting accreting supermassive black holes; due to their brightness, they are unique probes of the early universe. To date, only few quasars have been reported at $z > 6.5$ ($<$800 Myr after the Big Bang). In this work,…
Cold quasars are a rare population of luminous, unobscured quasars associated with host galaxies that have a high star formation rate. We aimed to study the host galaxies of sixty four of these cold quasars in order to probe how the…
Quasars are the visible signatures of super-massive black holes in the centres of distant galaxies. It has been suggested that quasars are formed during ``major merger events'' when two massive galaxies collide and merge, leading to the…
We have obtained deep, multi-band imaging observations around three of the most distant known quasars at redshifts z>6. Standard accretion theory predicts that the supermassive black holes present in these quasars were formed at a very…
One of the fundamental questions about quasars is related to their central supermassive black holes. The reason for the existence of these black holes with such a huge mass is still unclear and various models have been proposed to explain…
Model of supermassive black holes formation inside the clusters of primordial black holes is developed. Namely, it is supposed, that some mass fraction of the universe ~10^-3 is composed of the compact clusters of primordial (relic) black…
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…
It is now widely recognised that massive black holes must have had a fundamental influence on the formation of galaxies and vice versa. With current and imminent missions we aim to unravel much of this relationship for the last 10 Gyr of…