Astr 328 Jan 29, 2003: The distance scale  

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Measuring cluster velocity with different galaxy types

Discussion question

Virgocentric flow

Measuring H0 using Virgo

Using a better cluster: Fornax

Why Fornax is a better cluster

Averaging over local groups of galaxies

H0 plot from local galaxies

Go further out....

A word from the opposition

Secondary distance indicators

Surface brightness fluctuations

Illustrate with extreme case

As galaxies become more distant, their light gets smoother

Poisson distribution

Observational complications

SBF is for elliptical galaxies, not spirals

Metal-poor globular CMD

Metal-rich globular CMD

Globular cluster luminosity function

And its many problems