Related papers: Hyperaccreting black holes in galactic nuclei
The relativistic accretion rate of dark matter by a black hole is revisited. Under the assumption that the phase space density indicator, $Q=\rho_{\infty}/\sigma^3_{\infty}$, remains constant during the inflow, the derived accretion rate…
The origin of the supermassive black holes that power the most distant quasars observed is largely unknown. One hypothesis is that they grew rapidly from intermediate-mass seeds (~100 M_sun) left by the first stars. However, some previous…
Supermassive black holes in galaxy centres can grow by the accretion of gas, liberating energy that might regulate star formation on galaxy-wide scales. The nature of the gaseous fuel reservoirs that power black hole growth is nevertheless…
We perform two-dimensional radiation hydrodynamical simulations of accretion flows onto a black hole (BH) with a mass of $10^3\leq M_{\rm BH}/M_{\odot} \lesssim 10^6$ in order to study rapid growth of BHs in the early Universe. For…
Outflows are inevitably driven from the disk if the vertical component of the black hole (BH) gravity cannot resist the radiation force. We derive the mass loss rate in the outflows by solving a dynamical equation for the vertical gas…
We identify a physical mechanism that would have resulted in rapid, obscured growth of seed super-massive black-holes in galaxies at z>6. Specifically, we find that the density at the centre of typical high redshift galaxies was at a level…
We examine radiative standing shocks in advective accretion flows around stellar-mass black holes by 2D radiation hydrodynamic simulations, focusing on the super-Eddington accreting flow. Under a set of input flow parameters responsible for…
Narrow-Line Seyfert 1 galaxies (NLS1s) and Narrow-Line quasars (NLQs) seem to amount to ~ 10-30 % of active galactic nuclei (AGNs) in the local universe. Together with their average accretion rate, we argue that the black hole (BH) growth…
The rapid assembly of the massive black holes that power the luminous quasars observed at $z \sim 6-7$ remains a puzzle. Various direct collapse models have been proposed to head-start black hole growth from initial seeds with masses $\sim…
Super-Eddington accretion onto massive black hole seeds may be commonplace in the early Universe, where the conditions exist for rapid accretion. Direct collapse black holes are often invoked as a possible solution to the observation of…
We present the first results from two-dimensional simulations of radiatively-efficient accretion of metal-free gas onto intermediate-mass black holes. We fix the shape of the spectral energy distribution of the radiation produced near the…
We perform two-dimensional radiation hydrodynamical simulations of accretion flows onto black holes (BHs) at the nuclei of protogalaxies, and study the impact of mechanical and radiative feedback on rapid growth of BHs. The outflows deposit…
We have completed two years of photometric and spectroscopic monitoring of a large number of active galactic nuclei (AGNs) with very high accretion rates. In this paper, we report on the result of the second phase of the campaign, during…
Accreting black holes and neutron stars at luminosities above 0.01 of the critical Eddington luminosity have a lot of similarities, but also drastic differences in their radiation and power density spectra. The efficiency of energy release…
The radio emission from supermassive black holes in nearby early-type galaxies can be used to test possible explanations for their low luminosities. We calculate the expected contribution from thermal synchrotron emission from hot accretion…
Observations by the James Webb Space Telescope of the Universe at $z\gtrsim 4$ have shown that massive black holes (MBHs) appear extremely overmassive compared to the local correlation for active galactic nuclei. In some cases, these…
Discovery of high-redshift (z > 6) supermassive black holes (BHs) may indicate that the rapid (or super-Eddington) gas accretion has aided their quick growth. Here, we study such rapid accretion of the primordial gas on to intermediate-mass…
Using a set of zoomed-in cosmological simulations of high-redshift progenitors of massive galaxies, we isolate and trace the history of gas that is accreted by central supermassive black holes. We determine the origins of the accreted gas,…
Formation of supermassive black holes (BHs) remains a theoretical challenge. In many models, especially beginning from stellar relic "seeds," this requires sustained super-Eddington accretion. While studies have shown BHs can violate the…
This review provides an observational perspective on the fundamental properties of super-Eddington accretion onto supermassive black holes in quasars. It begins by outlining the selection criteria, particularly focusing on optical and UV…