A Fundamental Line for Elliptical Galaxies
  Recent studies have shown that massive galaxies in the distant universe are
surprisingly compact, with typical sizes about a factor of three smaller than
equally massive galaxies in the nearby universe. It has been suggested that
these massive galaxies grow into systems resembling nearby galaxies through a
series of minor mergers. In this model the size growth of galaxies is an
inherently stochastic process, and the resulting size-luminosity relationship
is expected to have considerable environmentally-dependent scatter. To test
whether minor mergers can explain the size growth in massive galaxies, we have
closely examined the scatter in the size-luminosity relation of nearby
elliptical galaxies using a large new database (Nair & Abraham 2010) of
accurate visual galaxy classifications. We demonstrate that this scatter is
much smaller than has been previously assumed, and may even be so small as to
challenge the plausibility of the merger driven hierarchical models for the
formation of massive ellipticals.
