Measurement of photon production in proton-proton collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector

The production of prompt photons in proton-proton collisions at the LHC provides a testing ground for perturbative QCD (pQCD) with a hard colourless probe. Since the dominant production mechanism in $pp$ collisions proceeds via the $qg\rightarrow g\gamma$ process, measurements of prompt-photon and photon plus jet production are sensitive at leading order (LO) to the gluon density in the proton. We present in this proceeding the latest ATLAS cross-section measurements of the ratio of the cross sections for inclusive isolated-photon production at centre-of-mass energies of 13 and 8 TeV, the measurements of isolated-photon plus jet cross sections at $\sqrt{s}$ = 13 TeV using a dataset with an integrated luminosity of 3.2 fb$^{-1}$ and the differential cross section for isolated-photon production measured at $\sqrt{s}$ = 13 TeV using an integrated luminosity of 36.1 fb$^{-1}$. The measurements are compared to next-to-leading-order (NLO) QCD as well as to next-to-next-to-leading-order (NNLO) QCD calculations.