  Angular correlation studies provide powerful insight into the energy loss of
hard scattered partons as they traverse the partonic medium produced in heavy
ion collisions at RHIC. These results are generally compared to jet
correlations in p+p collsisions where all correlation strength is attributed to
vacuum fragmentation. Strong modification to di-jet correlations has been
observed in A+A collisions at RHIC, most notably for the away side jet. Many
different effects, including the opacity of the medium, its response to energy
deposited by partons as they propagate, and modifications to the parton
fragmentation, are involved in producing the final correlation stuctures.
Understanding the interplay between these various effects is essential to
developing a complete picture of the medium. Measurements of jet correlations
involving direct photons provide a unique probe of jet fragmentation effects,
as photons are not strongly interacting. Additionally, systematic studies of
the away side structure as a function of $p_{T}$, as well as attempts to
include additional high $p_{T}$ trigger requirements, can help to distinguish
different energy loss mechanisms. We discuss recent PHENIX results from these
detailed studies of jet correlations in A+A and p+p collisions.

Nuclear Experiment