We present results from a harmonic decomposition of two-particle azimuthal correlations measured with the STAR detector in Au + Au collisions for energies ranging from √sNN = 7.7 to 200 GeV. The third harmonic υ23 {2} = ⟨cos3(ϕ1−ϕ2)⟩, where ϕ1−ϕ2 is the angular difference in azimuth, is studied as a function of the pseudorapidity difference between particle pairs Δη = η1− η2. Nonzero υ23 {2} is directly related to the previously observed large-Δη narrow-Δϕ ridge correlations and has been shown in models to be sensitive to the existence of a low viscosity quark gluon plasma phase. For sufficiently central collisions, υ23 {2} persist down to an energy of 7.7 GeV, suggesting that quark gluon plasma may be created even in these low energy collisions. In peripheral collisions at these low energies, however, υ23 {2} is consistent with zero. When scaled by the pseudorapidity density of charged-particle multiplicity per participating nucleon pair, υ23 {2} for central collisions shows a minimum near √sNN = 20 GeV
