  Dusty hyperluminous galaxies in the early universe provide unique
environments for studying the role of massive stars in the formation and
destruction of dust. At redshifts above 6, when the universe was less than 1
Gyr old, dust could have only condensed in the explosive ejecta of Type II
supernovae (SNe), since most of the progenitors of the AGB stars, the major
alternative source of interstellar dust, did not have time to evolve off the
main sequence. We present analytical models for the evolution of the gas, dust,
and metals in high redshift galaxies, with a special application to SDSS
J1148+5251, a hyperluminous quasar at z = 6.4. We show that an average SN must
condense at least 1 Msun of dust to account for the mass of dust in this
object, when grain destruction by supernova remnants (SNRs) is taken into
account. This required yield is in excess of ~0.05 Msun, the largest mass of
dust inferred from infrared observations of Cas A. If the yield of Cas A is
typical, then other processes, such as accretion onto preexisting grains in
molecular clouds is needed to produce the mass of dust in J1148+5251. For such
process to be effective, SNR must significantly increase, presumably by
non-evaporative grain-grain collisions during the late stages of their
evolution, the number of nucleation centers onto which refractory elements can
condense in molecular clouds.

Astrophysics