Abstract

Galaxies during the Epoch of Reionization

Andrei Mesinger (Scuola Normale Superiore)

The first galaxies are thought to play a leading role in the Epoch of Reionization (EoR). By extending our current census of high-z galaxies, JWST will shed light on this as-yet uncharted phase transition of our Universe. I will show how simple galaxy number counts can be used to provide: (i) Bayesian priors on galaxy astrophysics (such as the evolution of the ionizing escape fraction), and (ii) constraints on a possible small-scale cut-off in the matter power spectrum (as suggested by some alternative Dark Matter models). Moreover, the observability of Lyman alpha emission with JWST spectroscopy can be used as a sensitive probe of the EoR, using both: (i) the drop in the fraction of color-selected galaxies with strong Lyman alpha emission; (ii) the clustering of high-z Lyman alpha emitters.

Talk