  A search is presented for photonic signatures motivated by generalised models
of gauge-mediated supersymmetry breaking. This search makes use of $20.3{\rm
fb}^{-1}$ of proton-proton collision data at $\sqrt{s}=8$ TeV recorded by the
ATLAS detector at the LHC, and explores models dominated by both strong and
electroweak production of supersymmetric partner states. Four experimental
signatures incorporating an isolated photon and significant missing transverse
momentum are explored. These signatures include events with an additional
photon, lepton, $b$-quark jet, or jet activity not associated with any specific
underlying quark flavor. No significant excess of events is observed above the
Standard Model prediction and model-dependent 95% confidence-level exclusion
limits are set.
