Cosmology at low frequencies: The 21 cm transition and the high-redshift Universe

  title={Cosmology at low frequencies: The 21 cm transition and the high-redshift Universe},
  author={Steven R. Furlanetto and S. Peng Oh and Frank H. Briggs},
  journal={Physics Reports},

Unveiling the nature of dark matter with high redshift 21 cm line experiments

Observations of the redshifted 21 cm line from neutral hydrogen will open a new window on the early Universe. By influencing the thermal and ionization history of the intergalactic medium (IGM),

Redshifted 21‐cm observations of high‐redshift quasar proximity zones

The introduction of low-frequency radio arrays is expected to revolutionize the study of the reionization epoch. Observation of the contrast in redshifted 21-cm emission between a large H II region

What does the first highly redshifted 21-cm detection tell us about early galaxies?

The Experiment to Detect the Global Epoch of Reionization Signature (EDGES) recently reported a strong 21-cm absorption signal relative to the cosmic microwave background at $z \sim 18$. While its

The rich complexity of 21-cm fluctuations produced by the first stars

We explore the complete history of the 21-cm signal in the redshift range z = 7-40. This redshift range includes various epochs of cosmic evolution related to primordial star formation, and should be

EDGES result versus CMB and low-redshift constraints on ionization histories

We examine the results from the Experiment to Detect the Global Epoch of Reionization Signature (EDGES), which has recently claimed the detection of a strong absorption in the 21 cm hyperfine

The global 21-cm signal in the context of the high- z galaxy luminosity function

We build a new model for the global 21-cm signal that is calibrated to measurements of the high-z galaxy luminosity function (LF) and further tuned to match the Thomson scattering optical depth of

The imprint of the cosmic supermassive black hole growth history on the 21 cm background radiation

The redshifted 21 cm transition line of hydrogen tracks the thermal evolution of the neutral intergalactic medium (IGM) at "cosmic dawn," during the emergence of the first luminous astrophysical

Probing the Very First Galaxies with the SKA

We describe the use of the high redshift 21 cm signal to probe the very first galaxies to appear in the Universe. Using fast large volume simulations of the pre-Reionization epoch we have shown that

The signature of the first stars in atomic hydrogen at redshift 20

A simulation of the distribution of the first stars at redshift 20 is reported, finding that the 21-centimetre hydrogen signature of these stars is an enhanced fluctuation signal on the hundred-megaparsec scale, characterized by a flat power spectrum with prominent baryon acoustic oscillations.



21 Centimeter Fluctuations from Cosmic Gas at High Redshifts

The relatively large Thomson optical depth, τes, inferred recently from the WMAP observations suggests that the universe was reionized in a more complex manner than previously believed. However, the

Radio Signatures of H I at High Redshift: Mapping the End of the “Dark Ages”

The emission of 21 cm radiation from a neutral intergalactic medium (IGM) at high redshift is discussed in connection with the thermal and ionization history of the universe. The physical mechanisms

Radio Foregrounds for the 21 Centimeter Tomography of the Neutral Intergalactic Medium at High Redshifts

Absorption or emission against the cosmic microwave background (CMB) radiation may be observed in the redshifted 21 cm line if the spin temperature of the neutral intergalactic medium (IGM) prior to

The Reionization History at High Redshifts. I. Physical Models and New Constraints from Cosmic Microwave Background Polarization

The recent discovery of a high optical depth τ to Thomson scattering from the Wilkinson Microwave Anisotropy Probe (WMAP) data implies that significant reionization took place at redshifts z > 6.

H I 21 Centimeter Absorption beyond the Epoch of Reionization

We explore the possibility of detecting H I 21 cm absorption by the neutral intergalactic medium (IGM) toward very high redshift radio sources. The epoch considered is between the time when the first

Detecting the Earliest Galaxies through Two New Sources of 21 Centimeter Fluctuations

The first galaxies that formed at a redshift z ~ 20-30 emitted continuum photons with energies between the Lyα and Lyman limit wavelengths of hydrogen, to which the neutral universe was transparent

Probing beyond the Epoch of Hydrogen Reionization with 21 Centimeter Radiation

We use numerical simulations of hydrogen reionization by stellar sources in the context of ΛCDM cosmogonies to investigate the 21 (1 + z) cm radio signal expected from the diffuse intergalactic

Foregrounds for 21-cm observations of neutral gas at high redshift

We investigate a number of potential foregrounds for an ambitious goal of future radio telescopes such as the Square Kilometer Array (SKA) and the Low Frequency Array (LOFAR): spatial tomography of

HI fluctuations at large redshifts: III — Simulating the signal expected at GMRT

We simulate the distribution of neutral hydrogen (HI) at the redshiftsz = 1.3 and 3.4 using a cosmological N-body simulation along with a prescription for assigning HI masses to the particles. The HI