Morphology of Dwarf Galaxies in Isolated Satellite Systems
  The environmental dependence of the morphology of dwarf galaxies in isolated
satellite systems is analyzed to understand the origin of the dwarf galaxy
morphology using the visually classified morphological types of 5836 local
galaxies with $z \lesssim 0.01$. We consider six sub-types of dwarf galaxies,
dS0, dE, dE$_{bc}$, dSph, dE$_{blue}$, and dI, of which the first four
sub-types are considered as early-type and the last two as late-type. The
environmental parameters we consider are the projected distance from the host
galaxy ($r_{p}$), local and global background densities, and the host
morphology. The spatial distributions of dwarf satellites of early-type
galaxies are much different from those of dwarf satellites of late-type
galaxies, suggesting the host morphology combined with $r_{p}$ plays a decisive
role on the morphology of the dwarf satellite galaxies. The local and global
background densities play no significant role on the morphology of dwarfs in
the satellite systems hosted by early-type galaxies. However, in the satellite
system hosted by late-type galaxies, the global background densities of dE and
dSph satellites are significantly different from those of dE$_{bc}$,
dE$_{blue}$, and dI satellites. The blue-cored dwarf satellites (dE$_{bc}$) of
early-type galaxies are likely to be located at $r_{p} > 0.3$ Mpc to keep their
cold gas from the ram pressure stripping by the hot corona of early-type
galaxies. The spatial distribution of dE$_{bc}$ satellites of early-type
galaxies and their global background densities suggest that their cold gas is
intergalactic material accreted before they fall into the satellite systems.
