We simulate direct photon production in the evolution of viscous quark-gluon plasma medium. Photons from Compton and annihilation processes are considered. The viscous effect on photon production is very strong and reliable simulation is possible only in a limited $p_T$ range. For minimally viscous fluid ($\eta /s=0.08$), direct photons can be reliably computed only up to $p_T⩽1.3$ GeV. With reduced viscosity ($\eta /s=0.04$), the limit increases to $p_T⩽2$ GeV.

• Received 24 January 2011

DOI:https://doi.org/10.1103/PhysRevC.83.034905