•Galaxy distributions seen
in images are 2-d projections on the sky.
•Need
distances…easiest way is to use the Hubble flow and redshifts,
either photometric or spectra (best).
•Reminder –
SDSS and 2dF rule here now.
•Huchra and
Gellar’s “Z-machine” for the CfA survey as
recounted in “Lonely Hearts of the Cosmos” by
Dennis Overbye – Great!