### 39. Beyond Fornax: other relative distance determinations

In addition to the relative distances using the Tully-Fisher relation
discussed above, a set of relative distance moduli based on a number
of independent secondary distance indicators, including brightest
cluster galaxies, Tully-Fisher and supernovae is also available
(Jerjen & Tammann 1993).
We adopt, without modification,
their differential distance scale and tie into the Cepheid distance to
the Fornax cluster, which was part of their cluster sample. The
results are shown in Figure 37 which extends
the velocity-distance
relation out to more than 160 Mpc. No error bars are given in the
published compilation but it is clear from the plot that the observed
scatter is fully contained by 10% errors in distance or velocity.
This sample is now sufficiently distant to average over the
potentially biasing effects of large-scale flows, and yields a value
of *H*_{0} = 72 (± 1)_{r} km/sec
(random), with a systematic error of
10% being associated with the distance (but not the velocity) of the
Fornax cluster. Again the coincidence of
*H*_{0} at
Fornax with that for the far field, argues for Fornax being relatively
at rest with respect to the microwave background.

**Figure 37.** The velocity-distance
relation for 17 clusters of galaxies with published differential
distance moduli
(Jerjen & Tammann 1993)
scaled to the Fornax cluster. A
fit to the data gives a Hubble constant of *H*_{0} = 72 ± 1
km/sec/Mpc. As in Figure 36,
the solid lines mark one-sigma bounds on the observed internal scatter.