What heats the hot phase in active nuclei?

The authors summarize some constraints on the continuum in active galactic nuclei and discuss implications for the hot intercloud medium. First, there is now good evidence that the peak of the energy distribution may actually occur in the extreme ultraviolet 200 Å ≤ λ ≤1000 Å. Second, it is shown that the Compton temperature is TC ≈ 10⁷K, far too low for broad line region clouds to be stable against drag forces, or for the hot phase to be optically thin to observed X-rays. Finally, the authors discuss some dynamical problems with current models of the intercloud medium.