SuperMassive Blackholes grow from stellar BHs of star formation history?

The origin of the supermassive black hole masses M _SMBH discovered at the highest redshifts is still actively debated. Moreover the statistically significant relation of M _SMBH with bulge luminosities L _V , extended on several magnitude orders, confirms a common physical process linking small (<= 1pc) to large (kpcs) size scales. The Spectral Energy Distributions (SEDs) of two z=3.8 radio galaxies 4C41.17 and TN J2007-1316, best-fitted by evolved early type galaxy and starburst scenarios also imply masses of stellar remnants. Computed with the evolutionary code Pegase.3, the cumulated stellar black hole mass M _sBH reach up to several 10⁹M_⊙, similar to M _SMBH at same z. We propose the SMBH growth is due to the migration of the stellar dense residues (sBH) towards the galaxy core by dynamical friction. Discussed in terms of time-scales, this process which is linking AGN and star formation, also fully justifies the famous relation M _SMBH -L _V .