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We show that the rapid formation of super-massive black holes in quasars can indeed be understood in terms of major galaxy mergers followed by disk accretion. The necessary short disk evolution time can be achieved provided the disk viscosity is sufficiently large, which, for instance, is the case for hydrodynamic turbulence, unlimited by shock dissipation. We present numerical calculations for a representative case. This general picture can account for (a) the presence of highly luminous quasars at redshifts z > 6; (b) for the peak in quasar activity at z ~ 2; and (c) for a subsequent rapid disappearance of quasars at later epochs.
The presence of young massive stars orbiting on eccentric rings within a few tenths of a parsec of the supermassive black hole in the Galactic centre is challenging for theories of star formation. The high tidal shear from the black hole should tear
We report results of a project investigating the growth of super-massive black holes (BHs) by disk accretion. We find that the BH mass growth is quick enough to account for the inferred masses in the highest-redshift quasars, and the growth time is a
We study the angular resolution of the gravitational wave detector LISA and show that numerical relativity can drastically improve the accuracy of position location for coalescing Super Massive Black Hole (SMBH) binaries. For systems with total redsh
We discuss the central role played by X-ray studies to reconstruct the past history of formation and evolution of supermassive Black Holes (BHs), and the role they played in shaping the properties of their host galaxies. We shortly review the progres
We addressed the so far unexplored issue of outflows induced by exponentially growing power sources, focusing on early supermassive black holes (BHs). We assumed that these objects grow to $10^9;M_{odot}$ by z=6 by Eddington-limited accretion and con