Related papers: Fueling processes on (sub-)kpc scales
Gas clouds are present in the Galactic centre, where they orbit around the supermassive black hole. Collisions between these clumps reduce their angular momentum, and as a result some of the clumps are set on a plunging trajectory.…
Gas delivery to galactic centers powers nuclear starbursts and active galactic nuclei (AGNs), yet bar-driven inflow is generally expected to stall in a nuclear ring a few hundred parsecs across. Using three-dimensional Lagrangian…
For most of their lives, galaxies are surrounded by large and massive coronae of hot gas, which constitute vast reservoirs for gas accretion. This Chapter describes a mechanism that allows star-forming disc galaxies to extract gas from…
We present a comprehensive analysis of super-Eddington black hole accretion simulations that solve the GRMHD equations coupled with angle-discretized radiation transport. The simulations span a range of accretion rates, two black hole…
The Eddington ratio ($\lambda_{\rm Edd}$) of supermassive black holes (SMBHs) is a fundamental parameter that governs the cosmic growth of SMBHs. Although gas mass accretion onto SMBHs is sustained when they are surrounded by large amounts…
Galaxies must form and evolve via the acquisition of gas from the intergalactic environment, however the way this gas accretion takes place is still poorly understood. Star-forming galaxies are surrounded by multiphase halos that appear to…
Small primordial black holes could be captured by rocky planets or asteroids, consume their liquid cores from inside and leave hollow structures. We calculate the surface density and surface tension of a hollow structure around a black hole…
Due to the non-axisymmetric potential of the central bar, barred spiral galaxies form, in addition to their characteristic arms and bar, a variety of structures within the thin gas disk, like nuclear rings, inner spirals and dust-lanes. In…
We consider the problem of growing the largest supermassive black holes from stellar--mass seeds at high redshift. Rapid growth without violating the Eddington limit requires that most mass is gained while the hole has a low spin and thus a…
Mini-black holes made of dark matter that can potentially form in the interior of neutron stars have been always thought to grow by accreting the matter of the core of the star via a spherical Bondi accretion. However, neutron stars have…
Super-Eddington accretion is very efficient in growing the mass of a black hole: in a fraction of the Eddington time its mass can grow to an arbitrary large value if the feedback effect is not taken into account. However, since…
We compare accretion and black hole spin as potential energy sources for outbursts from AGN in brightest cluster galaxies (BCGs). Based on our adopted spin model, we find that the distribution of AGN power estimated from X-ray cavities is…
Super-massive black holes weighing up to $\sim 10^9 \, \mathrm{M_{\odot}}$ are in place by $z \sim 7$, when the age of the Universe is $\lesssim 1 \, \mathrm{Gyr}$. This implies a time crunch for their growth, since such high masses cannot…
The large majority of the accreting supermassive black holes in the Universe are obscured by large columns of gas and dust. The location and evolution of this obscuring material have been the subject of intense research in the past decades,…
When a supermassive black hole exists in the centre of a galaxy, an additional inner Lindblad resonance (ILR) exists inside the usual ILRs. We study gas dynamics in a weakly barred potential with a central supermassive black hole by using…
Supermassive stars born from pristine gas in atomically-cooled haloes are thought to be the progenitors of supermassive black holes at high redshifts. However, the way they accrete their mass is still an unsolved problem. In particular, for…
Great strides have been made in the last two decades in determining how galaxies evolve from their initial dark matter seeds to the complex structures we observe at z=0. The role of mergers has been documented through both observations and…
We consider a black hole accreting spherically from the surrounding medium. If accretion produces a luminosity close to the Eddington limit the hole acquires a net charge so that electrons and ions can fall with the same velocity. The…
Galactic nuclei are unique laboratories for the study of processes connected with the accretion of gas onto supermassive black holes. At the same time, they represent challenging environments from the point of view of stellar dynamics due…
A number of long-standing puzzles, such as the origin of ultrahigh-energy cosmic rays, could perhaps be solved if we found a mechanism for effectively transferring energy from black holes to particles and, correspondingly, accelerating the…