Isolated-prompt $\gamma-$hadron correlations $I_{\rm pQCD}$ for central Pb$-$Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ $\mathrm{TeV}$ measured by the ALICE Collaboration, and $I_{\rm AA}$ for central Au$-$Au collisions at $\sqrt{s_{\rm NN}} = 200$ $\mathrm{GeV}$ measured by the PHENIX [48] and STAR [47] Collaborations at RHIC, also in central collisions. The boxes represent the systematic uncertainties, while the vertical bars indicate the statistical uncertainties. For ALICE, the blue-open boxes represent the $\mu$ scale uncertainty for the denominator NLO pQCD calculation for pp collisions.