On The Nature of Fossil Galaxy Groups
  We present a new sample of 25 fossil groups (FGs) at z < 0.1, along with a
control sample of seventeen bright ellipticals located in non-fossil systems.
Both the global properties of FGs (e.g. X-ray luminosity) as well as the
photometric properties (i.e. isophotal shape parameter, a4) and spectroscopic
parameters (e.g. the alpha-enhancement) of their first-ranked ellipticals are
consistent with those of the control sample. This result favors a scenario
where FGs are not a distinct class of systems, but rather a common phase in the
life of galaxy groups. We also find no evidence for an evolutionary sequence
explaining the formation of galaxies in fossil systems through the merging of
galaxies in compact groups.
