Hydrogen reionization in the Illustris universe

Reionization of the early Universe

On the Reionization of the Universe

I present first principle model calculations for the reionization of the Universe, which provide simple diagnostics to identify the reionization sources. Within this frame, I also discuss the results derived from the Hubble Ultra-Deep Field observations, and the possible need for future observations with JWST to provide the final answer.

Connecting Reionization to the Local Universe

We present results of combined N-body and three-dimensional reionization calculations to determine the relationship between reionization history and local environment in a volume 1 Gpc h−1 across and a resolution of about 1 Mpc. We resolve the formation of about 2× 106 halos of mass greater than ∼ 10M⊙ at z = 0, allowing us to determine the relationship between halo mass and reionization epoch ...

Signatures of Stellar Reionization of the Universe

The high ionization level and non-zero metallicity (∼ 1% Z ⊙) of the intergalactic gas at redshifts z ∼ < 5 implies that nonlinear structure had started to form in the universe at earlier times than we currently probe. In Cold Dark Matter (CDM) cosmologies, the first generation of baryonic objects emerges at redshifts z ∼ 10–50. Here we examine the observable consequences of the possibility tha...

The first stars in the universe and cosmic reionization.

The earliest generation of stars, far from being a mere novelty, transformed the universe from darkness to light. The first atoms to form after the Big Bang filled the universe with atomic hydrogen and a few light elements. As gravity pulled gas clouds together, the first stars ignited and their radiation turned the surrounding atoms into ions. By looking at gas between us and distant galaxies,...