Super-Eddington Accretion Disks around Supermassive Black Holes

By Yan-Fei 飞 Jiang 姜燕, James M. Stone, S. Davis. Astrophysical Journal, 2017

196 citations recorded by the source corpus.

We use global three-dimensional radiation magnetohydrodynamical simulations to study accretion disks onto a black hole with accretion rates varying from to . We initialize the disks with a weakly magnetized torus centered at either 50 or 80 gravitational radii, leading to self-consistent turbulence generated by the magnetorotational instability (MRI). The inner regions of all disks have radiation pressure ∼104–106 times the gas pressure. Nonaxisymmetric density waves that steepen into spiral shocks form as gas flows toward the black hole. Maxwell stress from MRI turbulence can be larger than the Reynolds stress only when the net vertical magnetic flux is sufficiently large. Outflows are formed with a speed of ∼0.1–0.4c. When the accretion rate is smaller than , outflows are launched from ∼10 gravitational radii, and the radiative efficiency is ∼5%–7%. For an accretion rate reaching , most of the funnel region near the rotation axis becomes optically thick, and the outflow is launched from beyond 50 gravitational radii. The radiative efficiency is reduced to 1%. We always find that the kinetic energy luminosity associated with the outflow is at most ∼15%–30% of the radiative luminosity. The mass flux in the outflow is ∼15%–50% of the net mass accretion rates. We discuss the implications of our simulation results on the observational properties of these disks.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/7858707d242aca50b46a876279266d5c39a63e43

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

Citations in the corpus

Titans of the early Universe: The Prato statement on the origin of the first supermassive black holes (2018, background): “In particular, the recent radiative magnetohydrodynamic simulations of Jiang, Stone, and Davis (2017), which are among the few to study accretion onmassive black holes rather than stellar mass black holes, exhibit radiative efficiencies that are an order of magnitude higher than those in the slim…”