  Dwarf galaxies are important tracers of small-scale cosmological structure,
yet much of our knowledge about these systems comes from the limited sample of
dwarf galaxies within the Local Group. To make a comprehensive inventory of
dwarf populations in the local Universe, we require effective methods for
deriving distance estimates for large numbers of faint, low surface brightness
objects. Here we test the surface brightness fluctuation (SBF) method,
traditionally applied to brighter early-type galaxies, on a sample of 20 nearby
dwarf galaxies detected in the COSMOS field. These objects are partially
resolved in HST ACS images, and have confirmed redshift distances in the range
17-130 Mpc. We discuss the many model choices required in applying the SBF
method, and explore how these affect the final distance estimates. Amongst
other variations on the method, when applying the SBF method, we alter the
standard equation to include a term accounting for the power spectrum of the
background, greatly improving our results. For the most robust modelling
choices, we find a roughly Gaussian SBF signal that correlates linearly with
distance out to distances of 50-100 Mpc, but with only a fraction of the power
expected. At larger distances, there is excess power relative to that
predicted, probably from undetected point sources. Overall, obtaining accurate
SBF distances to faint, irregular galaxies remains challenging, but may yet
prove possible with the inclusion of more information about galaxy properties
and point source populations, and the use of more advanced techniques.
