2 - Modern Framework
from Part One - Breakthrough Astrophysics
Published online by Cambridge University Press: 10 December 2025
Summary
Quasar absorption line studies have matured into a modern science that has contributed to the development of our contemporary cosmological paradigm, ranging from the Big Bang, across Cosmic Noon, to the Present Epoch. Researchers focus on key ions, transitions, and absorption lines because they are most common in the Universe. Each of these lines has a unique cosmic visibility in that there is a strong relationship between the observed wavelength of a redshifted line, the cosmic era in which it originated, and the type of astrophysical environment it probes. In this chapter, we outline the main eras of the evolution of the Universe, describe the phases and ionization conditions of the gas in the Universe, and show the connection between ions/transitions and the cosmic era and gas phases they probe.
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- Quasar Absorption Lines , pp. 33 - 54Publisher: Cambridge University PressPrint publication year: 2025
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