The Epoch of Assembly of Two Galaxy Groups: A comparative study
  Nearby galaxy groups of comparable mass to the Local Group show global
variations that reflect differences in their evolutionary history. Satellite
galaxies in groups have higher levels of gas deficiency as the distance to
their host decreases. The well established gas deficiency profile of the Local
Group reflects an epoch of assembly starting at z<10. We investigate whether
this gas deficiency profile can be used to determine the epoch of assembly for
other nearby groups. We choose the M81 group as this has the most complete
inventory, both in terms of membership and multi-wavelength observations. We
expand our earlier evolutionary model of satellite dwarf galaxies to not only
confirm this result for the Local Group but show that the more gas-rich M81
group is likely to have assembled at a later time (z<1-3).
