  We experimentally and numerically characterize rapidly rotating radiatively
driven thermal convection, beyond the sole heat transport measurements reported
in Bouillaut et al. (2021). Based on a suite of direct numerical simulations
(DNS) and additional processing of the experimental data collected by Bouillaut
et al. (2021), we report the simultaneous validation of the scaling predictions
of the `geostrophic turbulence' regime -- the diffusivity-free or `ultimate'
regime of rapidly rotating convection -- for the heat transport, the
temperature fluctuations, the flow speed and the flow structure. Radiatively
driven convection thus appears as a versatile setup for the laboratory
observation of the diffusivity-free regimes of various convective flows of
geophysical and/or astrophysical interest.
