  We consider the effect of a supernova (SN) explosion in a very massive binary
that is expected to form in a portion of Population III stars with the mass
higher than 100$M_\odot$. In a Population III binary system, a more massive
star can result in the formation of a BH and a surrounding accretion disc. Such
BH accretion could be a significant source of the cosmic reionization in the
early universe. However, a less massive companion star evolves belatedly and
eventually undergoes a SN explosion, so that the accretion disc around a BH
might be blown off in a lifetime of companion star. In this paper, we explore
the dynamical impact of a SN explosion on an accretion disc around a massive
BH, and elucidate whether the BH accretion disc is totally demolished or not.
For the purpose, we perform three-dimensional hydrodynamic simulations of a
very massive binary system, where we assume a BH of $10^3 M_{\odot}$ that
results from a direct collapse of a very massive star and a companion star of
$100 M_{\odot}$ that undergoes a SN explosion. We calculate the remaining mass
of a BH accretion disc as a function of time. As a result, it is found that a
significant portion of gas disc can survive through three-dimensional
geometrical effects even after the SN explosion of a companion star. Even if
the SN explosion energy is higher by two orders of magnitude than the binding
energy of gas disc, about a half of disc can be left over. The results imply
that the Population III BH accretion disc can be a long-lived luminous source,
and therefore could be an important ionizing source in the early universe.
