The Reionization of the Universe by the First Stars and Quasars

  title={The Reionization of the Universe by the First Stars and Quasars},
  author={Abraham Loeb and Rennan Barkana},
  journal={Annual Review of Astronomy and Astrophysics},
  • A. Loeb, R. Barkana
  • Published 23 October 2000
  • Physics
  • Annual Review of Astronomy and Astrophysics
▪ Abstract The formation of the first stars and quasars marks the transformation of the universe from its smooth initial state to its clumpy current state. In popular cosmological models, the first sources of light began to form at a redshift z = 30 and reionized most of the hydrogen in the universe by z = 7. Current observations are at the threshold of probing the hydrogen reionization epoch. The study of high-redshift sources is likely to attract major attention in observational and… 
The First Sources of Light
I review recent progress in understanding the formation of the first stars and quasars. The initial conditions for their emergence are given by the now firmly established model of cosmological
Evolution of the ionizing background and the epoch of reionization from the spectra of z ∼ 6 quasars
We study the process of cosmic reionization and estimate the ionizing background in the intergalactic medium (IGM) using the Lyman series absorption in the spectra of the four quasars at 5.7 3) are
The First Stars
▪ Abstract We review recent theoretical results on the formation of the first stars in the universe, and emphasize related open questions. In particular, we discuss the initial conditions for
Observations of the first light and the epoch of reionization
Studying the first generation of stars,galaxies and supermassive black holes as well as the epoch of reionization is one of the fundamental questions of modern astrophysics.The last few years have
The Dark Ages of the Universe and hydrogen reionization
One of the milestones in the cosmic history is the formation of the first luminous objects and Hydrogen reionization. The standard theory of cosmic structure formation predicts that the first
The duration of reionization constrains the ionizing sources.
We investigate how the nature of the galaxies that reionized the Universe affects the duration of reionization. We contrast two sets of models: one in which galaxies on the faint side of the
The Epoch of Reionization
The Universe’s dark ages end with the formation of the first generation of galaxies. These objects start emitting ultraviolet radiation that carves out ionized regions around them. After a sufficient
Ultraviolet luminosity density of the universe during the epoch of reionization
Arcmin-scale spatial fluctuations are reported in one of the deepest sky surveys with the Hubble Space Telescope in five wavebands between 0.6 and 1.6 μm to find the ultraviolet luminosity density of galaxies at redshifts greater than 8 to be .
The physical properties and cosmic environments of quasars in the first Gyr of the universe
Luminous quasars at redshift z &6, i.e. .1 Gyr after the Big Bang, are formidable probes of the early universe, at the edge of the Epoch of Reionization. These sources are predicted to be found in
Observing the First Stars, One Star at a Time
Gamma-Ray Bursts (GRBs) are believed to originate in compact remnants (black holes or neutron stars) of massive stars. Their high luminosities make them detectable out to the edge of the visible


Identifying the Reionization Redshift from the Cosmic Star Formation Rate
We show that the cosmic star formation rate per comoving volume should exhibit a distinct drop around the reionization redshift, when the H II regions in the intergalactic medium around individual
The formation of nuclei in newly formed galaxies and the evolution of the quasar population
A model to explain the evolution of the quasar luminosity function is presented. At intermediate and high redshifts, the formation of'new'black holes at each step in the hierarchical growth of
Signatures of Stellar Reionization of the Universe
The high ionization level and nonzero 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
Spectral Features from the Reionization Epoch
Emission lines in hydrogen can be used to measure the approximate redshift of the reionization of the universe. This is an important measurement given the lack of a convincing theoretical prediction
Observational Signatures of the First Quasars
We study the observational signatures of a potential population of low-luminosity quasars at high redshifts in a ΛCDM cosmology. We derive the evolution of the quasar luminosity function at fainter
Local Group Dwarf Galaxies and the Star Formation Law at High Redshift.
  • Gnedin
  • Physics
    The Astrophysical journal
  • 2000
It is found that the observational data are consistent with the orthodox Schmidt law with a star formation efficiency of about 4% if the star formation is continuous (during the first 3 Gyr), and the efficiency is proportionally higher if most of the gas in the dwarfs was consumed and never replenished.
Radiative Transfer in a Clumpy Universe. III. The Nature of Cosmological Ionizing Sources
The history of the transition from a neutral intergalactic medium (IGM) to one that is almost fully ionized can reveal the character of cosmological ionizing sources. We study the evolution of the
Suppressing the formation of dwarf galaxies via photoionization
In hierarchical clustering theories, some sort of feedback mechanism is required to prevent most of the baryonic material collapsing into subgalactic objects at high redshifts. It is argued that a
Zero-Metallicity Stars and the Effects of the First Stars on Reionization.
The hard stellar spectra are inconsistent with the observations of He ii opacity in the intergalactic medium at z approximately 3, indicating that the period of metal-free star formation ended before that epoch.