Simulating intergalactic medium reionization

Cosmic Dark Ages: Minihalos and the Intergalactic Medium before Reionization

The H atoms inside minihalos (i.e. halos with virial temperatures Tvir ≤ 10 K, in the mass range roughly from 10M⊙ to 10 8 M⊙) during the cosmic dark ages in a ΛCDM universe produce a redshifted background of collisionally-pumped 21-cm line radiation which can be seen in emission relative to the cosmic microwave background (CMB). Previously, we used semi-analytical calculations of the 21-cm sig...

A Statistical Analysis of Intergalactic Medium Transmission Approaching Reionization

We use hydrodynamic cosmological simulations to explore the evolution of the intergalactic medium (IGM) transmissivity from z=2 through the epoch of reionization. We simulate a concordance ΛCDM model in a 9.6 Mpc box with a comoving spatial resolution of 37.5 kpc. Reionization is treated in the optically thin approximation using an ultraviolet background (UVB) that includes evolving stellar and...

Probing the Intergalactic Medium out to the Reionization Epoch

We propose to attempt to determine the epoch at which the intergalactic medium (IGM) was reionized by searching for characteristic spectral features in the redshift-smeared ‘GunnPeterson’ Lyα foreground absorption in the spectra of UV-bright objects uncovered by NGST at z ∼> 5. If – as is widely anticipated – localized sources such as young galaxies and quasars were responsible for reionizing t...

Lyman-Break Galaxies and the Reionization of the Intergalactic Medium

Near-infrared observations of Lyman-break galaxies at redshifts z ∼ 3 are beginning to provide constraints on ages, star-formation histories, dust content, metallicities, and stellar masses. At present, uncertainties of more than an order of magnitude are typical for many of these parameters. It is nonetheless interesting to ask what the stellar-population models imply for the existence and lum...

Intergalactic Medium