As a result of its lower mass, the influence of Fornax on the local velocity field is less dramatic than that of the Virgo cluster. Clearly, Fornax is a much more interesting site for a test of the local expansion rate. M100 and NGC 1365 are each individually marked by arrows showing their relative disposition with respect to the main body and cores of their respective clusters.
Units are arcmin.
It is both a probe of the local expansion velocity field, and Fornax is a major jumping-off point for a variety of secondary distance indicators which can be used to probe a volume of space at least 1,000 times larger. At least three lines of evidence independently suggest that the first galaxy to be observed, NGC 1365 is a physical member of the Fornax cluster. First, NGC 1365 is almost directly along our line of sight to Fornax . In addition, NGC 1365 is also coincident with the Fornax cluster in velocity space. The velocity off-set of NGC 1365 is only half of the cluster velocity dispersion.