We estimate the energy release of black hole formation to the intra-cluster
medium of the Coma cluster and find that this is comparable to the present day
energy content. Therefore an energetic and maybe hydrostatic influence is
possible. Our calculations rely on the assumption of an universal black hole to
galaxy mass ratio (more exactly: spheroidal mass component of the stellar
population), for which there is growing evidence. On a cosmological scale,
there is also an energy release of black hole formation comparable to what is
expected to be present within the thermal gas, caused by the process of
structure formation. This indicates an important dynamical influence, neglected
by present day structure formation simulations. This estimate of cosmological
black hole energy release is independent of the black hole to galaxy mass
ratio, but consistent with its value.Comment: 4 pages, LaTeX2e, no figures, accepted by A&A Letter
