Pairwise dwarf galaxy formation and galaxy downsizing: some clues from
  extremely metal-poor Blue Compact Dwarf galaxies
  Some of the extremely metal-poor Blue Compact Dwarf galaxies (XBCDs) in the
nearby universe form galaxy pairs with remarkably similar properties. This fact
points to an intriguing degree of synchronicity in the formation history of
these binary dwarf galaxies and raises the question as to whether some of them
form and co-evolve pairwise (or in loose galaxy groups), experiencing recurrent
mild interactions and minor tidally induced star formation episodes throughout
their evolution. We argue that this hypothesis offers a promising conceptual
framework for the exploration of the retarded previous evolution and recent
dominant formation phase of XBCDs.
