  We have used sensitive archival data from the Infrared Space Observatory
(ISO) to make maps of the edge-on low SFR galaxy, NGC 5907, in 6 different MIR
bands: LW2, LW5, LW6, LW7, LW8, and LW10, covering the spectrum from 6.5 to
15.0 microns and including several narrow bands that isolate the infrared
aromatic spectral features commonly referred to as PAHs. Most of the MIR
emission is dominated by PAHs and it is likely that emission from VSGs
contribute only negligibly except in the broad IRAS-equivalent band. The flux
ratios are typical of galaxies with low SFRs or quiesent regions within
galaxies (e.g M~83) and a very high PAH/continuum ratio is observed. The PAH
emission follows the CO distribution and also shows some correlation within the
disk with the lambda 850 micron distribution. However, the PAH emission also
reaches larger galactocentric radii than the CO and other correlations suggest
that the PAHs are also more widespread. A significant new discovery is the
presence of PAHs in the halo of the galaxy. In the narrow bands that isolate
single PAH features, the emission shows structure similar to high latitude
features seen in other galaxies in other tracers. The features extend as far as
6.5 kpc from the plane but scale heights of 3.5 kpc are more typical. The
(lambda 11.3/lambda7.7) ratio also appears to increase with distance from the
major axis. To our knowledge, this is the first time PAHs have been seen in the
halo of an external galaxy. Just as significantly, they are seen in a low SFR
galaxy, suggesting that strong SNe and winds are not necessary for these large
molecules to reach high latitudes.
