A smooth and fast end of the dark ages of the universe
Félix MIRABEL
Sap, IRFU, CEA-Saclay.
Résumé :
After a spectacular birth, with the glow of the Big Bang fading away
and the first atoms of hydrogen being formed, our Universe quickly
became a dull place, with the first stars and galaxies yet to appear.
How long these cosmic dark ages lasted and how they came to an end
are questions of outmost importance in cosmology.
Based on recent theoretical and observational results, I will show that
besides the ultraviolet radiation from primordial massive stars, X-rays
and relativistic jets from their black hole fossils, must have played
an important role at the dawn of the Universe. In this context,
contrary to the prevailing view that the early Universe had
a "Swiss-cheese"-like appearance that lasted several hundred million years,
the dark ages may have had a smooth and fast end. These could be good news
for the future probes of the dark ages by means of the redshifted 21 cm line
of atomic hydrogen.
