In article ,
(Charles R Kiss) writes:
I downloaded the rotation rates, optical radius, and redshift, of 80
galaxies.

The data of these 80 galaxies were retrieved objects from Persic and
Salucci via Matthewson [ca.1997].

I determined the ratio: rotation rate/optical radius and plotted the
result against their respective redshift, obtaining what appears to
be a linear graph.

Doesn't this mean: Vrot/Ropt = K*Vsys?

If I understand you correctly, the above can be rearranged as
Vrot/D = Ropt, where D is distance in some (probably strange) units.
In other words, galaxy angular diameter increases with mass (which is
proportional to some power of Vrot) and is inversely proportional to
distance.

This is pretty crude and can no doubt be refined, and I haven't
looked at your input data at all, so perhaps it's wrong altogether.
It's just the first thought that comes to mind.

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Steve Willner Phone 617-495-7123
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