Very high redshift quasars and the rapid emergence of super-massive
  black holes
  The observation of quasars at very high redshift such as Poniuaena is a
challenge for models of super-massive black hole (SMBH) formation. This work
presents a study of SMBH formation via known physical processes in star-burst
clusters formed at the onset of the formation of their hosting galaxy. While at
the early stages hyper-massive star-burst clusters reach the luminosities of
quasars, once their massive stars die, the ensuing gas accretion from the still
forming host galaxy compresses its stellar black hole (BH) component to a
compact state overcoming heating from the BH--BH binaries such that the cluster
collapses, forming a massive SMBH-seed within about a hundred Myr. Within this
scenario the SMBH--spheroid correlation emerges near-to-exactly. The
highest-redshift quasars may thus be hyper-massive star-burst clusters or young
ultra-compact dwarf galaxies (UCDs), being the precursors of the SMBHs that
form therein within about 200 Myr of the first stars. For spheroid masses
<10^9.6 Msun a SMBH cannot form and instead only the accumulated nuclear
cluster remains. The number evolution of the quasar phases with redshift is
calculated and the possible problem of missing quasars at very high redshift is
raised. SMBH-bearing UCDs and the formation of spheroids are discussed
critically in view of the high redshift observations. A possible tension is
found between the high star-formation rates (SFRs) implied by downsizing and
the observed SFRs, which may be alleviated within the IGIMF theory and if the
downsizing times are somewhat longer.
