A Survey of 3 to 5.4 Micron Emission From Planetary Nebulae using
  SOFIA/FLITECAM
  Here we present the results of an airborne 3-5.4$\mu$m spectroscopic study of
three young, Carbon-rich planetary nebulae IC 5117, PNG 093.9-00.1, and BD
$+$30 3639. These observations were made using the grism spectroscopy mode of
the FLITECAM instrument during airborne science operations onboard NASA's
Stratospheric Observatory for Infrared Astronomy (SOFIA). The goal of this
study is to characterize the 3.3 $\mu$m and 5.25 $\mu$m PAH dust emission in
planetary nebulae and study the evolution of PAH features within evolved stars
before their incorporation into new stellar systems in star-forming regions.
Targets were selected from IRAS, KAO and ISO source lists, and were previously
observed with FLITECAM on the 3-meter Shane telescope at Lick Observatory to
allow direct comparison between the ground and airborne observations. We
measure PAH emission equivalent width and central wavelength, classify the
shape of the PAH emission, and determine the PAH/Aliphatic ratio for each
target. The 3.3 $\mu$m PAH emission feature is observed in all three objects.
PNG 093.9-00.1 exhibits NGC 7027-like aliphatic emission in the 3.4 to 3.6
$\mu$m region while IC 5117 and BD +30 3639 exhibit less aliphatic structure.
All three PNs additionally exhibit PAH emission at 5.25 $\mu$m.
