摘要：Supermassive black hole dynamics during galaxy mergers is crucial in determining the rate
of black hole mergers and cosmic black hole growth. As simulations achieve higher
resolution, it becomes important to assess whether the black hole dynamics is influenced
by the treatment of the interstellar medium in different simulation codes. We compare
simulations of black hole growth in galaxy mergers with two codes: the smoothed particle
hydrodynamics code gasoline, and the adaptive mesh refinement code
ramses. We seek to identify predictions of these models that are robust despite
differences in hydrodynamic methods and implementations of subgrid physics. We find that
the general behavior is consistent between codes. Black hole accretion is minimal while
the galaxies are well-separated (and even as they fly by within 10 kpc at the first
pericenter). At late stages, when the galaxies pass within a few kpc, tidal torques drive
nuclear gas inflow that triggers bursts of black hole accretion accompanied by star
formation. We also note quantitative discrepancies that are model dependent: our
ramses simulations show less star formation and black hole growth, and a
smoother gas distribution with larger clumps and filaments than our gasoline
simulations. We attribute these differences primarily to the subgrid models for black
hole fueling, feedback, and gas thermodynamics. The main conclusion is that differences
exist quantitatively between codes, and this should be kept in mind when making
comparisons with observations. However, both codes capture the same dynamical behaviors in
terms of triggering black hole accretion, star formation, and black hole dynamics, which
is reassuring.
关键词：galaxies: active;galaxies: evolution;galaxies: formation;galaxies: interactions;galaxies: star formation
