Dynamical-friction galaxy-gas coupling and cluster cooling flows

  title={Dynamical-friction galaxy-gas coupling and cluster cooling flows},
  author={Amr A. El-Zant and Woong-Tae Kim and Marc Kamionkowski},
  journal={Monthly Notices of the Royal Astronomical Society},
We revisit the notion that galaxy motions can efficiently heat intergalactic gas in the central regions of clusters through dynamical friction. For plausible values of the galaxy mass-to-light ratio, the heating rate is comparable with the cooling rate due to X-ray emission. Heating occurs only for supersonic galaxy motions, so the mechanism is self-regulating: it becomes efficient only when the gas sound speed is smaller than the galaxy velocity dispersion. We illustrate with the Perseus… 

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