Using Supernovae to Study Cosmology
Remember Type Ia supernovae:
the explosion of a ~ 1.4 Msun white dwarf. We saw that these supernovae
were pretty fair standard candles, and were extremely bright. That's exactly
what we want to use for the redshift-distance test.
But there's a significant drawback to using Type Ia Sne.
You
gotta find them...
Using supernovae to study cosmology
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Take a BIG picture of the sky.
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Come back next month and take the same picture.
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Compare the two. Differences?
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If you find a possible supernova, take a spectrum of it and
make sure it is a Type Ia SNe.
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Also take a spectrum of the galaxy it lives in, to find its
redshift.
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Watch the supernova as it fades, so we can get its peak apparent
magnitude. This is important -- you probably didn't catch it when it was
at its peak, so we need to fit it to a standard light curve to derive its
peak magnitude.
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Keep doing this so you have a big sample of high redshift
supernovae. Then compare those supernovae to ones at lower redshift.
Some plots, courtesy of the supernovae
cosmology project at LBL and the high
z supernova search team at CfA
Example of a high-z supernova discovery
SNe + Host galaxies with HST
Redshift Magnitude Plots
More recent supernovae data:
