... Behemoth black hole found in an unlikely place . ... black holes . ... Quasar superclusters found . The strong clustering of quasars 10 billion light-years away helps astronomers infer that they lie in dark-matter "halos." ... This illustration shows the distribution of dark matter, massive halos, and luminous quasars in a simulation of the early universe, shown 1.6 billion years after the Big Bang. ... The strong clustering shows that the quasars lie within massive concentrations of dark matter. ...