Stochastic heating of cooling flows
  It is generally accepted that the heating of gas in clusters of galaxies by
active galactic nuclei (AGN) is a form of feedback. Feedback is required to
ensure a long term, sustainable balance between heating and cooling. This work
investigates the impact of proportional stochastic feedback on the energy
balance in the intracluster medium. Using a generalised analytical model for a
cluster atmosphere, it is shown that an energy equilibrium can be reached
exponentially quickly. Applying the tools of stochastic calculus it is
demonstrated that the result is robust with regard to the model parameters,
even though they affect the amount of variability in the system.
