  We extend our holographic analysis of the emission of photons by a strongly
coupled plasma subject to a very intense external magnetic field. We previously
showed that in a particular model, any photon produced by the plasma had to be
in its only polarization state parallel to the reaction plane. In this paper we
consider a construction that relaxes a formerly imposed constraint, permitting
the emission of photons with either out-plane or in-plane polarization. This
constitutes a completion of our former study because the fully back-reacted
equations decouple for these two polarization states in such a manner that
those involving the in-plane are identical to the ones we explored previously.
In view of the above, part of the details concerning the calculations and of
the numerical results for the differential rate of emitted photons that we
present here correspond exactly to those omitted in our preceding letter. One
of our main results is that the production of photons is increased by the
introduction of a non-vanishing magnetic field with an intensity up to a value
$B_{\vartheta}$, above which the effect is reversed and said production becomes
lower than the $B=0$ case. The characteristic intensity $B_{\vartheta}$ depends
on the propagation direction and tends to zero as the photon momentum becomes
aligned with the magnetic field. Additionally, we also show that the magnetic
field has the effect of increasing the value of the elliptic flow, providing a
possible explanation for the excess measured in collision experiments. The
holographic model is constructed using an effective five-dimensional action
that includes a scalar field in addition to the constant magnetic field.
