  Direct photons, being colorless objects, provide an unmodified control
particle that can be used in conjunction with jets to probe the quark-gluon
plasma. To leading order the direct photon momentum balances the momentum of
opposing jets and can therefore provide a clean handle on the jet energy.
Therefore, angular correlations with direct photons provide a mechanism to
study the fragmentation of the opposing jet without performing jet
reconstruction. Jet fragmentation modification has been measured previously in
PHENIX in central Au+Au collisions. Recent RHIC runs offer the potential to
study these observables in heavy ion collisions with greater statistics and
over different collision systems including asymmetric collision geometries. In
this talk we present results of isolated direct photon-triggered correlations
in d+Au collisions and discuss the constraints of cold nuclear matter effects
on the fragmentation functions. We also present the latest results with higher
statistics on direct photon-triggered correlations in Au+Au collisions
including differential measurements of fragmentation function modification.
Finally, we present the status of the centrality and collision species
dependence of these observables, including comparisons to related dihadron
correlations. Together these results can give a view of jet modification going
from small to large system size.
