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