Related papers: Inhomogeneous Reionization Regulated by Radiative …
The ionizing background of cosmic hydrogen is an important probe of the sources and absorbers of ionizing radiation in the post-reionization universe. Previous studies show that the ionization rate should be very sensitive to changes in the…
We present a self-consistent, semi-analytical LCDM model of star formation and reionization. For the cosmological parameters favored by the WMAP data, our models consistently reproduce the optical depth to reionization, redshift of…
The ionizing photon production efficiency, $\xi_{ion}$, is a critical parameter that provides a number of physical constraints to the nature of the early Universe, including the contribution of galaxies to the timely completion of the…
Reionization is an inhomogeneous process, thought to begin in small ionized bubbles of the intergalactic medium (IGM) around overdense regions of galaxies. Recent Lyman-alpha (Ly$\alpha$) studies during the epoch of reionization show…
We determine the abundance of i'-band drop-outs in the HST/ACS GOODS surveys and the Hubble Ultra Deep Field (UDF). The majority of these sources are likely to be z~6 galaxies whose flux decrement arises from Lyman-alpha absorption. We have…
The transformation of cold neutral intergalactic hydrogen into a highly ionized warm plasma marks the end of the cosmic dark ages and the beginning of the age of galaxies. The details of this process reflect the nature of the early sources…
Motivated by recent evidence that the epoch of reionization of hydrogen may have ended at a redshift as low as z~6 we consider the detectability of the sources responsible for this reionization. The main idea is that reionization places…
We study the connection of star formation to atomic (HI) and molecular hydrogen (H$_2$) in isolated, low metallicity dwarf galaxies with high-resolution ($m_{\rm gas}$ = 4 M$_\odot$, $N_{\rm ngb}$ = 100) SPH simulations. The model includes…
Radiative feedback from stars and galaxies has been proposed as a potential solution to many of the tensions with simplistic galaxy formation models based on $\Lambda$CDM, such as the faint end of the UV luminosity function. The total…
Quasar absorption spectra measurements suggest that reionization proceeded rapidly, ended late at $z \sim 5.5$, and was followed by a flat ionizing background evolution. Simulations that reproduce this behavior often rely on a fine tuned…
We present numerical methods for including stellar feedback in galaxy-scale simulations. We include heating by SNe (I & II), gas recycling and shock-heating from O-star & AGB winds, HII photoionization, and radiation pressure from stellar…
The first generation of stars that formed directly from the primordial gas played a crucial role in the early phase of the reionization of the universe. Because of the short lifetimes of these stars the metals produced in their cores were…
An ionizing UV background (UVB) inhibits gas accretion and photo-evaporates gas from the shallow potential wells of small, dwarf galaxies. During cosmological reionization, this effect can result in negative feedback: suppressing…
Recent observations have set the first constraints on the epoch of reionization (EoR), corresponding to the formation epoch of the first luminous objects. Studies of Gunn-Peterson (GP) absorption, and related phenomena, suggest a…
We present numerical simulations of how a 120 M$_\odot$ primordial star regulates star formation in nearby cosmological halos at $z \sim$ 20 by photoevaporation. Our models include nine-species primordial chemistry and self-consistent…
We explore the impact of cosmic reionization on nearby isolated dwarf galaxies using a compilation of SFHs estimated from deep HST data and a cosmological hydrodynamical simulation of the Local Group. The nearby dwarfs show a wide diversity…
Recently, we have presented the first large-scale radiative transfer simulations of reionization. Here we present new simulations which extend the source halo mass range downward to 10^8M_solar, to capture the full range of halo masses…
Reionization is thought to have occurred in the redshift range of $6 < z < 9$, which is now being probed by both deep galaxy surveys and CMB observations. Using halo abundance matching over the redshift range $5<z<8$ and assuming smooth,…
The universe was reionized by redshift z ~ 6 by a small fraction of the baryons in the universe, which released energy following their condensation out of a cold, dark, and neutral IGM into the earliest galaxies. The theory of this…
This work studies the connection between the first galaxies and their hosting dark matter halos in the early Universe when Reionization is concluding. Our numerical models (already presented in an earlier study) trace the star formation…