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

@article{Barkana2004DetectingTE,
  title={Detecting the Earliest Galaxies through Two New Sources of 21 Centimeter Fluctuations},
  author={Rennan Barkana and Abraham Loeb},
  journal={The Astrophysical Journal},
  year={2004},
  volume={626},
  pages={1-11}
}
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 except at the Lyman series resonances. As these photons redshifted or scattered into the Lyα resonance, they coupled the spin temperature of the 21 cm transition of hydrogen to the gas temperature, allowing it to deviate from the microwave background temperature. We show that the fluctuations in the… 

Figures from this paper

Detecting early galaxies through their 21‐cm signature
New observations over the next few years of the emission of distant objects will help unfold the chapter in cosmic history around the era of the first galaxies. These observations will use the
Possible interaction between baryons and dark-matter particles revealed by the first stars
TLDR
The analysis indicates that the spatial fluctuations of the 21-centimetre signal at cosmic dawn could be an order of magnitude larger than previously expected and that the dark-matter particle is no heavier than several proton masses, well below the commonly predicted mass of weakly interacting massive particles.
Probing the first galaxies with the Square Kilometer Array
Observations of anisotropies in the brightness temperature of the 21 cm line of neutral hydrogen from the period before reionization would shed light on the dawn of the first stars and galaxies. In
The signature of the first stars in atomic hydrogen at redshift 20
TLDR
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.
The X-ray spectra of the first galaxies: 21 cm signatures
The cosmological 21cm signal is a physics-rich probe of the early Universe, encoding information about both the ionization and the thermal history of the intergalactic medium (IGM). The latter is
Growth of Linear Perturbations before the Era of the First Galaxies
We calculate the evolution of linear density and temperature perturbations in a universe with dark matter, baryons and radiation, from cosmic recombination until the epoch of the first galaxies. In
The global 21-centimeter background from high redshifts
We consider the evolution of the sky-averaged 21-cm background during the early phases of structure formation. Using simple analytic models, we calculate the thermal and ionization histories,
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
...
...

References

SHOWING 1-10 OF 52 REFERENCES
21 Centimeter Fluctuations from Cosmic Gas at High Redshifts
The relatively large Thomson optical depth, ?es, 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
A Method for Separating the Physics from the Astrophysics of High-Redshift 21 Centimeter Fluctuations
Fluctuations in the 21 cm brightness from cosmic hydrogen at redshifts z 6 have their source in the primordial density perturbations from inflation, as well as the radiation from galaxies. We propose
Redshifted 21 Centimeter Signatures around the Highest Redshift Quasars
The Lyα absorption spectrum of the highest redshift quasars indicates that they are surrounded by giant H II regions, a few megaparsecs in size. The neutral gas around these H II regions should emit
UNUSUALLY LARGE FLUCTUATIONS IN THE STATISTICS OF GALAXY FORMATION AT HIGH REDSHIFT
We show that various milestones of high-redshift galaxy formation, such as the formation of the first stars or the complete reionization of the intergalactic medium, occurred at different times in
Measuring the small-scale power spectrum of cosmic density fluctuations through 21 cm tomography prior to the epoch of structure formation.
TLDR
This work calculates the evolution of the spin temperature for this transition and the resulting anisotropies that are imprinted on the CMB sky due to linear density fluctuations during this epoch.
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
The cosmic microwave background radiation fluctuations from H i perturbations prior to reionization
Loeb and Zaldarriaga have recently proposed that observations of the cosmic microwave background radiation (CMBR) brightness temperature fluctuations produced by H I inhomogeneities prior to
21 CENTIMETER TOMOGRAPHY OF THE INTERGALACTIC MEDIUM AT HIGH REDSHIFT
We investigate the 21 cm signature that may arise from the intergalactic medium (IGM) prior to the epoch of full reionization (z > 5). In scenarios in which the IGM is reionized by discrete sources
The Spin-Kinetic Temperature Coupling and the Heating Rate due to Lyα Scattering before Reionization: Predictions for 21 Centimeter Emission and Absorption
We investigate the interaction of Lyα photons produced by the first stars in the universe with intergalactic hydrogen prior to reionization. The background Lyα spectral profile is obtained by solving
...
...