25/10/2018-SHAO Astrophysics Colloquium

Title: Reionization after Planck and before JWST

Speaker: Piero Madau (University of California, Santa Cruz)

Time: 3 pm, October 25(Thursday)

Location: Lecture Hall, 3rd floor

Abstract: The reionization of the all-pervading intergalactic medium marks a turning point in the history of structure formation in the Universe. A combination of cosmic microwave background  data and quasar absorption line spectra shows that this transition must have begun 

in earnest around redshift 10, and that the Universe was nearly fully reionized some 0.9 Gyr after the Big Bang. The details of this process reflect the nature of the first astrophysical sources of radiation and heating, the power-spectrum of density fluctuations on small scales, the thermodynamics and chemistry of cosmic baryons, the star formation and black hole accretion history, and a complex network of poorly understood feedback mechanisms. These outstanding issues remain crucial missing links in galaxy formation and cosmology research. In this talk I will  survey the key aspects of reionization-era phenomenology, describe the diverse range of techniques and tools currently available in this field, and review some recent challenges in our understanding of cosmic dawn.