  In a framework of a multi-phase transport model with both partonic and
hadronic interactions, azimuthal correlations between trigger particles and
associated scattering particles in Au + Au collisions at $\sqrt{s_{NN}}$ = 200
GeV/$c$ have been studied by the mixing-event technique. The Mach-like
structure has been observed in correlation function for central collisions. It
is shown that the Mach-like structure is basically born in the partonic process
and further developed in hadronic rescattering process. However, hadronic
rescattering alone cannot reproduce the amplitude of Mach-like cone on away
side, therefore partonic cascade process is necessary to describe the amplitude
of Mach-like cone on away side in experiment. In addition, three-particle
correlations have been investigated in central Au + Au collisions with the AMPT
model, and the results support the conclusion that partonic cascade processes
enhance the opening angle of Mach-like cone structures.
