An observer's guide to the (Local Group) dwarf galaxies: predictions for
  their own dwarf satellite populations
  A recent surge in the discovery of new ultrafaint dwarf satellites of the
Milky Way has inspired the idea of searching for faint satellites, $10^3\,
\mathrm{M_{\odot}} < M_* < 10^6\, \mathrm{M_{\odot}}$, around less massive
field galaxies in the Local Group. Such satellites would be subject to weaker
environmental influences than Milky Way satellites, and could lead to new
insights on low mass galaxy formation. In this paper, we predict the number of
luminous satellites expected around field dwarf galaxies by applying several
abundance matching models and a reionization model to the dark-matter only
\textit{Caterpillar} simulation suite. For three of the four abundance matching
models used, we find a $>99\%$ chance that at least one satellite with stellar
mass $M_*> 10^5\, \mathrm{M_{\odot}}$ exists around the combined five Local
Group field dwarf galaxies with the largest stellar mass. When considering
satellites with $M_*> 10^4\, \mathrm{M_{\odot}}$, we predict a combined $5-25$
satellites for the five largest field dwarfs, and $10-50$ for the whole Local
Group field dwarf population. Because of the relatively small number of
predicted dwarfs, and their extended spatial distribution, a large fraction
each Local Group dwarf's virial volume will need to be surveyed to guarantee
discoveries. We compute the predicted number of satellites in a given field of
view of specific Local Group galaxies, as a function of minimum satellite
luminosity, and explicitly obtain such values for the Solitary Local dwarfs
survey. Uncertainties in abundance matching and reionization models are large,
implying that comprehensive searches could lead to refinements of both models.
