  We have analysed the preliminary PHENIX data on the transverse momentum
distribution of direct photons in 0-20% centrality Au+Au collisions at
$\sqrt{s_{NN}}$=200 GeV. In ideal hydrodynamics, data are explained if Au+Au
collision produces Quark-Gluon-Plasma at the temperature $T_i$=400 MeV, at an
initial time $\tau_i$=0.6 fm. PHENIX data are not explained in the alternate
scenario when Au+Au collisions produces hot hadronic gas with initial
temperature within physically acceptable limit.
