Detection of 3.3 Micron Aromatic Feature in the Supernova Remnant N49
  with AKARI
  We present an infrared study of the supernova remnant (SNR) N49 in the Large
Magellanic Cloud with the near-infrared (NIR; 2.5 - 5 {\mu}m) spectroscopic
observations performed by AKARI. The observations were performed as a coarse
spectral mapping to cover most of the bright region in the east, which enables
us to compare the distribution of various line emission and to examine their
correlation. We detect the 3.3 {\mu}m aromatic feature in the remnant, which is
for the first time to report the presence of the 3.3 {\mu}m aromatic feature
related to a SNR. In the line maps of H2 1-0 O(3), 3.3 {\mu}m feature, and
Br{\alpha}, the distribution of the aromatic feature shows overall correlation
with those of other emissions together with regional differences reflecting the
local physical conditions. By comparison with other archival imaging data at
different wavelengths, the association of the aromatic emission to other
ionic/molecular emission is clarified. We examine archival Spitzer IRS data of
N49 and find signatures of other polycyclic aromatic hydrocarbon (PAH) features
at 6.2, 7.7, and 11.3 {\mu}m corresponding to the 3.3 {\mu}m aromatic feature.
Based on the band ratios of PAHs, we find that PAHs in N49 are not only
dominantly neutral but also small in size. We discuss the origin of the PAH
emission in N49 and conclude that the emission is either from PAHs that have
survived the shock or PAHs in the preshock gas heated by radiative precursor.
