  To investigate the structure and composition of the dusty interstellar medium
(ISM) of low surface brightness (LSB) disk galaxies, we have used
multiwavelength photometry to construct spectral energy distributions for three
low-mass, edge-on LSB galaxies. We use Monte Carlo radiation transfer codes
that include the effects of transiently heated small grains and polycyclic
aromatic hydrocarbon molecules to model and interpret the data. We find that
unlike the high surface brightness galaxies previously modeled, the dust disks
appear to have scale heights equal to or exceeding their stellar scale heights.
This result supports the findings of previous studies that low mass disk
galaxies have dust scale heights comparable to their stellar scale heights and
suggests that the cold ISM of low mass, LSB disk galaxies may be stable against
fragmentation and gravitational collapse. This may help to explain the lack of
observed dust lanes in edge-on LSB galaxies and their low current star
formation rates.
