  We present an integral field spectroscopic study of radiative shocks in 27
nearby ultraluminous and luminous infrared galaxies (U/LIRGs) from the Great
Observatory All-sky LIRG Survey, a subset of the Revised Bright Galaxy Sample.
Our analysis of the resolved spectroscopic data from the Wide Field
Spectrograph (WiFeS) focuses on determining the detailed properties of the
emission line gas, including a careful treatment of multi- component emission
line profiles. The resulting information obtained from the spectral fits are
used to map the kinematics of the gas, sources of ionizing radiation and
feedback present in each system. The resulting properties are tracked as a
function of merger stage. Using emission line flux ratios and velocity
dispersions, we find evidence for widespread, extended shock excitation in many
local U/LIRGs. These low-velocity shocks become an increasingly important
component of the optical emission lines as a merger progresses. We find that
shocks may account for as much as half of the H{\alpha} luminosity in the
latest-stage mergers in our sample. We discuss some possible implications of
our result and consider the presence and effects of AGN on the spectra in our
sample.
