The Fornax Deep Survey (FDS) with VST XII: Low surface brightness dwarf
  galaxies in the Fornax cluster
  In this work we use Max-Tree Objects, (MTO) on the FDS data in order to
detect previously undetected Low surface brightness (LSB) galaxies. After
extending the existing Fornax dwarf galaxy catalogs with this sample, our goal
is to understand the evolution of LSB dwarfs in the cluster. We also study the
contribution of the newly detected galaxies to the faint end of the luminosity
function. We test the detection completeness and parameter extraction accuracy
of MTO. We then apply MTO to the FDS images to identify LSB candidates. The
identified objects are fitted with 2D S\'ersic models using GALFIT and
classified based on their morphological appearance, colors, and structure. With
MTO, we are able to increase the completeness of our earlier FDS dwarf catalog
(FDSDC) 0.5-1 mag deeper in terms of total magnitude and surface brightness.
Due to the increased accuracy in measuring sizes of the detected objects, we
also add many small galaxies to the catalog that were previously excluded as
their outer parts had been missed in detection. We detect 265 new LSB dwarf
galaxies in the Fornax cluster, which increases the total number of known
dwarfs in Fornax to 821. Using the extended catalog, we show that the
luminosity function has a faint-end slope of -1.38+/-0.02. We compare the
obtained luminosity function with different environments studied earlier using
deep data but do not find any significant differences. On the other hand, the
Fornax-like simulated clusters in the IllustrisTNG cosmological simulation have
shallower slopes than found in the observational data. We also find several
trends in the galaxy colors, structure, and morphology that support the idea
that the number of LSB galaxies is higher in the cluster center due to tidal
forces and the age dimming of the stellar populations. The same result also
holds for the subgroup of large LSB galaxies, so-called ultra-diffuse galaxies.
