Astr 328 Feb 5, 2003: The distance scale: Type Ia supernovae  

Biases: the Scott effect

Why this will make H0 too large

Malmquist bias

What happens to H0?

H0 increases

Type Ia supernovae

Start with a CO white dwarf

Why are they so bright and relatively uniform?

Light curve physics

Light curve plot cf decay times

Second order effect: correlation between peak brightness and decline rate

Differently shaped light curves

SN Ia spectra during decline

Correction for different decline rate

Correction plots

Reddening corrections

B-V color evolution

Lookback times can be huge: problem?

Example of high-redshift detections

Worries

Use of SN Ia as absolute indicators?