  In this paper we introduce an equation of state (EOS) of quark matter within
the framework of Dyson-Schwinger equations (DSEs) to study the structure of
compact stars. The smooth crossover from hadronic matter to quark matter in the
hybrid star is studied. We compare different strategies to obtain crossover
EOSs and find a new way to construct two-solar-mass hybrid stars with even a
relatively soft quark EOS, while earlier works show that the quark EOS should
be stiff enough to support a massive hybrid star.
