Feeding SMBHs through supersonic turbulence and ballistic accretion

Understand

It has long been recognised that the main obstacle to accretion of gas onto supermassive black holes (SMBHs) is large specific angular momentum.

• It is feared that the gas settles in a large scale disc, and that accretion would then proceed too inefficiently to explain the masses of the observed SMBHs.
• Here we point out that, while the mean angular momentum in the bulge is very likely to be large, the deviations from the mean can also be significant.
• Indeed, cosmological simulations show that velocity and angular momentum fields of gas flows onto galaxies are very complex.