Piecing together the puzzle of NGC 5253: abundances, kinematics and WR
  stars
  We present Gemini-S/GMOS-IFU optical spectroscopy of four regions near the
centre of the nearby (3.8 Mpc) dwarf starburst galaxy NGC 5253. This galaxy is
famous for hosting a radio supernebula containing two deeply embedded massive
super star clusters, surrounded by a region of enhanced nitrogen abundance that
has been linked to the presence of WR stars. We detected 11 distinct sources of
red WR bump (CIV) emission over a 20" (~350 pc) area, each consistent with the
presence of ~1 WCE-type star. WC stars are not found coincident with the
supernebula, although WN stars have previously been detected here. We performed
a multi-component decomposition of the H\alpha\ line across all four fields and
mapped the kinematics of the narrow and broad (FWHM = 100-250 km/s) components.
These maps paint a picture of localised gas flows, as part of multiple
overlapping bubbles and filaments driven by the star clusters throughout the
starburst. We confirm the presence of a strong H\alpha\ velocity gradient over
~4.5" (~80 pc) coincident with the region of N/O enhancement, and high gas
density known from previous study, and interpret this as an accelerating
ionized gas outflow from the supernebula clusters. We measure the ionized gas
abundances in a number of regions in the outer IFU positions and combine these
with measurements from the literature to assess the radial abundance
distribution. We find that the O/H and N/H profiles are consistent with being
flat. Only the central 50 pc exhibits the well-known N/O enhancement, and we
propose that the unusually high densities/pressures in the supernebula region
have acted to impede the escape of metal-enriched hot winds from the star
clusters and allow them to mix with the cooler phases, thus allowing these
freshly processed chemicals to be seen in the optical.
