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PHENIX has used the versatility of RHIC to map out low $p_{T}$ direct photonproduction as function of collision system size and beam energy. For systemswith a size corresponding to a $dN_{ch}/d\eta$ larger than 20-30, we observe alarge yield of direct photons, a large azimuthal anisotropy with respect to thereaction plane, and a characteristic centrality dependence of $dN_{\gamma}/dy\propto (dN_{ch}/d\eta)^{\alpha}$, with $\alpha \sim$ 1.2. \\ In thisproceeding, we will present new results from Au+Au collisions at$\sqrt{s_{NN}}$ = 39, 62.4 and 200 GeV. After subtracting the prompt photoncomponent, the inverse slope for the $p_{T}$ range from 1-2 GeV/$c$ is 250MeV/$c$, but increases to about 400 MeV/$c$ for the range from 2 to 4 GeV/$c$.Within the experimental uncertainty, there is no indication of a system sizedependence of the inverse slope. Furthermore, the system size dependence of theyield, expressed through the power $\alpha$, remains independent of $p_{T}$over the entire observed range from 1 to 6 GeV/$c$. Like the large yield andazimuthal anisotropy, these features, while qualitatively consistent with theemission of thermal photons from the quark gluon plasma, elude a quantitativedescription through theoretical model calculations.

Low $p_T$ direct photon production at RHIC measured with PHENIX