Bibcode
Durier, Fabrice; Dalla Vecchia, C.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 419, Issue 1, pp. 465-478.
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1
2012
Citations
174
Refereed citations
169
Description
We perform simulations of feedback from supernovae and black holes with
smoothed particle hydrodynamics. Such strong perturbations are
inaccurately handled with standard time integration schemes, leading to
poor energy conservation, a problem that is commonly overlooked. We show
for the first time that, in the absence of radiative cooling,
concordance of thermal and kinetic feedback are achieved when using an
accurate time integration. In order to preserve the concordance of
feedback methods when using a more efficient time integration scheme -
as for instance the hierarchical time-step scheme - we implement a
modified version of the time-step limiter proposed by Saitoh &
Makino. We apply the limiter to general test cases, and first show that
this scheme violates energy conservation up to almost 4 orders of
magnitude when energy is injected at random times. To tackle this issue,
we find it necessary not only to ensure a fast information propagation,
but also to enforce a prompt response of the system to the energy
perturbation. The method proposed here to handle strong feedback events
enables us to achieve energy conservation at per cent level in all
tests, even if all the available energy is injected into only one
particle. We argue that concordance of feedback methods can be achieved
in numerical simulations only if the time integration scheme preserve a
high energy conservation level.