  We obtain the thermal photon and dilepton production rates in a strongly
coupled quark-gluon plasma (QGP) at both zero and nonzero baryon chemical
potential using a bottom-up Einstein-Maxwell-Dilaton (EMD) holographic model
that is in good quantitative agreement with the thermodynamics of
$(2+1)$-flavor lattice QCD around the crossover transition for baryon chemical
potentials up to 400 MeV, which may be reached in the beam energy scan (BES) at
RHIC. We find that increasing the temperature $T$ and the baryon chemical
potential $\mu_B$ enhances the peak present in both spectra. We also obtain the
electric charge susceptibility, the DC and AC electric conductivities and the
electric charge diffusion as functions of $T$ and $\mu_B$. We find that
electric diffusive transport is suppressed as one increases $\mu_B$. At zero
baryon density, we compare our results for the DC electric conductivity and the
electric charge diffusion with the latest lattice data available for these
observables and find reasonable agreement around the crossover transition.
Therefore, our holographic results may be used to constraint the magnitude of
the thermal photon and dilepton production rates in a strongly coupled QGP,
which we found to be at least one order of magnitude below perturbative
estimates.
