in the line of sight. This is done in figure 3. Black squares represent the masses of SMBHs at z = 0 derived from simulations while red squares represent data taken from the literature. There is a good agreement between simulated and observed data but some objects seem to have a higher black hole mass for the corresponding stellar velocity dispersion of their host galaxies. In particular, this is the case for NGC 5252 and Cygnus A as it can be seen in the considered figure. In our proposed scenario, these objects have not evolved intermittently but rather in a very short time scale in the early evolutionary phases of the universe, being presently the relics of such an active past.

If some SMBHs seem to have masses above that expected from the $M - \sigma$ relation as figure 3 suggests, there are other arguments indicating that these objects followed indeed a different evolutionary path. At a given redshift, the simulations permit to compute the mass distribution of SMBHs. This is shown in figure 4, which indicates that no SMBHs with masses above $10^7 ~ M_\odot$ is present at $z = 5$, in agreement with the evolution of individual black 