Widely Extended [OIII] 88 um Line Emission around the 30 Doradus Region
  Revealed with AKARI FIS-FTS
  We present the distribution map of the far-infrared [OIII] 88um line emission
around the 30 Doradus (30 Dor) region in the Large Magellanic Cloud obtained
with the Fourier Transform Spectrometer of the Far-Infrared Surveyor onboard
AKARI. The map reveals that the [OIII] emission is widely distributed by more
than 10' around the super star cluster R136, implying that the 30 Dor region is
affluent with interstellar radiation field hard enough to ionize O^{2+}. The
observed [OIII] line intensities are as high as (1-2) x 10^{-6} W m^{-2}
sr^{-1} on the peripheral regions 4'-5' away from the center of 30 Dor, which
requires gas densities of 60-100 cm^{-3}. However the observed size of the
distribution of the [OIII] emission is too large to be explained by massive
stars in the 30 Dor region enshrouded by clouds with the constant gas density
of 10^2 cm^{-3}. Therefore the surrounding structure is likely to be highly
clumpy. We also find a global correlation between the [OIII] and the
far-infrared continuum emission, suggesting that the gas and dust are well
mixed in the highly-ionized region where the dust survives in clumpy dense
clouds shielded from the energetic photons.
