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Recombination and the CMB
The cosmic microwave background today has K. It was released when the Universe had cooled to about K. (a) Find the redshift of recombination. (b) At what wavelength did the radiation peak then, and in what band do we detect it now? (c) By what factor has the photon energy density dropped since?
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Reading resources
Material that covers the physics behind this problem.
- An Introduction to Modern AstrophysicsCarroll & Ostlie
The standard reference for olympiad-level astrophysics. Chapters 1-3 cover the celestial sphere, orbits and the magnitude system.
Textbook - Ohio State Astronomy Lecture NotesOhio State University
Clear university-level notes on stars, galaxies and cosmology with derivations you can follow line by line.
Lecture notes - Cosmology CalculatorEdward L. Wright (UCLA)
Converts redshift into distances, lookback time and scale factors. Use it to sanity-check cosmology answers.
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