[mmaimcal] distant Milky Way?

[Michael Rupen]

One comment on Bryan's calculations -- for a rotating disk you usually win 
quite a bit because (for a flat rotation curve) the signal is concentrated in 
two narrow peaks rather than spread uniformly across the total linewidth.
Of course in many galaxies the CO is concentrated in a region where solid
body rotation is more appropriate, and then the intensity is more uniform
over frequency.  Anyhow I'd say his assumptions are on the pessimistic
side.  Particularly if you (spatially) resolve the CO you'll win by having
multiple channels as well, both because of the line shape, and because the
gas is expected to move in a specific fashion rather than changing location
randomly from channel to channel.  

-- Michael