The lopsided distribution of satellites of isolated central galaxies
  Satellites are not randomly distributed around their central galaxies but
show polar and planar structures. In this paper, we investigate the
axis-asymmetry or lopsidedness of satellite galaxy distributions around
isolated galaxies in a hydrodynamic cosmological simulation. We find a
statistically significant lopsided signal by studying the angular distribution
of the satellite galaxies' projected positions around isolated central galaxies
in a two-dimensional plane. The signal is dependent on galaxy mass, color and
large-scale environment. Satellites that inhabit low-mass blue hosts, or
located further from the hosts show the most lopsided signal. Galaxy systems
with massive neighbors exhibit stronger lopsidedness. This satellite
axis-asymmetry signal also decreases as the universe evolves. Our findings are
in agreement with recent observational results, and they provide a useful
perspective for studying galaxy evolution, especially on the satellite
accretion, internal evolution and interaction with the cosmic large-scale
structure.
