The luminosity function (LF) of the M 81 group has been
constructed from total B magnitudes given in Table 1 (click here)
and is shown in Fig. B1 (click here). Possible members are included -
however not those suspected to be cirrus clouds (cf. Appendix A). The
absolute magnitude scale is based on a distance of 4 Mpc for the M 81
group, corresponding to m-M=28.01. The limit of completeness for
this LF depends on the depth of the photographic survey of
Börngen et al. (1982), which is not well defined. We guess a magnitude
of completeness is 
.
For comparison, we also show the LF of the LG in
Fig. B1 (click here). The data are taken from Côté (1995),
who converted the
Van Den Bergh (1992) V magnitudes into B
magnitudes. The
Van Den Bergh (1992) LF
includes all LG members within a distance of 1 Mpc. The estimated
limit of completeness here is 
. Besides a factor of 
difference in richness - the M 81
group being richer than the LG - the two LF's are clearly compatible
with each other.
Figure B1: Luminosity function of the M 81 group of galaxies
(solid line) compared with that of the Local Group (shaded)