Can galaxy collisions shut down the gas supply to a massive black hole?
Analytical modelling and three-dimensional hydrodynamics show how a central encounter can remove a black hole’s surrounding gas reservoir.
Destruction of the central black hole gas reservoir through head-on galaxy collisions
Destruction of the central black hole gas reservoir through head-on galaxy collisions. Miki, Yohei; Mori, Masao; Kawaguchi, Toshihiro, Nature Astronomy, 5, 478-484 (2021).
The models use collision parameters motivated by Andromeda and examine the stripping of a torus-shaped reservoir during a head-on galaxy encounter.
Main result
An incoming gas-bearing satellite can remove the circumnuclear gas that would otherwise fuel accretion. The study derives conditions under which this shutdown is possible.
Scientific implications
Galaxy interactions can help regulate active galactic nucleus duty cycles through both enhanced inflow and disrupted fuelling, depending on encounter geometry.
Scope and limitations
The mechanism removes fuel, not the black hole. Its effectiveness depends on the collision orbit and relative gas columns.
