The formation of shell galaxies similar to NGC 7600 in the cold dark
  matter cosmogony
  We present new deep observations of 'shell' structures in the halo of the
nearby elliptical galaxy NGC 7600, alongside a movie of galaxy formation in a
cold dark matter universe (available at
http://www.virgo.dur.ac.uk/shell-galaxies). The movie, based on an ab initio
cosmological simulation, shows how continuous accretion of clumps of dark
matter and stars creates a swath of diffuse circumgalactic structures. The
disruption of a massive clump on a near-radial orbit creates a complex system
of transient concentric shells which bare a striking resemblance to those of
NGC 7600. With the aid of the simulation we interpret NGC 7600 in the context
of the CDM model.
