An Integral Field Study of Abundance Gradients in Nearby LIRGs
  We present for the first time metallicity maps generated using data from the
Wide Field Spectrograph (WiFeS) on the ANU 2.3m of 9 Luminous Infrared Galaxies
(LIRGs) and discuss the abundance gradients and distribution of metals in these
systems. We have carried out optical integral field spectroscopy (IFS) of
several several LIRGs in various merger phases to investigate the merger
process. In a major merger of two spiral galaxies with preexisting disk
abundance gradients, the changing distribution of metals can be used as a
tracer of gas flows in the merging system as low metallicity gas is transported
from the outskirts of each galaxy to their nuclei. We employ this fact to probe
merger properties by using the emission lines in our IFS data to calculate the
gas-phase metallicity in each system. We create abundance maps and subsequently
derive a metallicity gradient from each map. We compare our measured gradients
to merger stage as well as several possible tracers of merger progress and
observed nuclear abundances. We discuss our work in the context of previous
abundance gradient observations and compare our results to new galaxy merger
models which trace metallicity gradient. Our results agree with the observed
flattening of metallicity gradients as a merger progresses. We compare our
results with new theoretical predictions that include chemical enrichment. Our
data show remarkable agreement with these simulations.
