Two channels for the formation of compact dwarf galaxies in clusters of
  galaxies
  We have identified two channels for the formation of compact dwarf galaxies
in the Illustris simulation by reconstructing mass and distance histories of
candidates located in the vicinity of the simulation's most massive cluster
galaxies. One channel is tidal stripping of Milky Way mass galaxies that form
outside of clusters and eventually sink into them, spiraling in toward central
massive objects. Second channel of formation is an in-situ formation (in
reference to the parent cluster) of dwarf mass galaxies, with negligible
evolution and limited change in stellar mass. We find 19 compact dwarf galaxies
at the centers of 14 clusters, consistent with observations. 30% of them have
external origin while 70% are formed in-situ.
