  We study the role of running coupling and the effect of variation of the
thermal quark mass on contribution of the collinear bremsstrahlung and
annihilation to photon emission in $AA$ collisions in a scheme similar to that
used in our previous jet quenching analyses. We find that for a scenario with
the thermal quark mass $m_q\sim 50-100$ MeV contribution of the higher order
collinear processes summed with the $2\to 2$ processes can explain a
considerable part ($\sim 50$\%) of the experimental photon spectrum at $k_T\sim
2-3$ GeV for Au+Au collisions at $\sqrt{s}=0.2$ TeV. But for $m_q=300$ MeV and
for the thermal quark mass predicted by the HTL scheme the theoretical
predictions underestimate considerably the experimental spectrum.
