Ponente
Prof.
Jordi Miranda-Escudé
(ICREA & IEC, UB, Spain)
Descripción
Observations in the 21-cm line can probe different phases of
reionization: an initial one where the atomic medium is cold and is seen in
absorption at the highest redshifts, and the later signal of 21-cm emission
from a heated medium before it is ionized. The emission signal is the easier
one to observe in upcoming years, and it can arise from low-density regions
that are less ionized than high-density ones, but also from high-density clumps
that are more abundant in high-density regions, associated with sites of galaxy formation that can be observed also as damped Lyman alpha absorbers.
Cross-correlation studies with other sources and emission lines will be
essential to understand the origin of the 21-cm signal when it is detected.
