Recognizing the first radiation sources through their 21 cm signature
@article{Chuzhoy2006RecognizingTF, title={Recognizing the first radiation sources through their 21 cm signature}, author={Leonid Chuzhoy and Marcelo A. Alvarez and Paul R. Shapiro}, journal={The Astrophysical Journal}, year={2006}, volume={648} }
At the beginning of the reionization epoch, radiation sources produce fluctuations in the redshifted 21 cm background. We show that different types of sources (such as miniquasars, Population II and III stars, supernovae, etc.) produce distinct signatures in the 21 cm signal radial profiles and statistical fluctuations, through which they can be identified. Furthermore, we show that the 21 cm signal from X-ray-emitting sources is much easier to observe than was expected, due to a previously…
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References
SHOWING 1-10 OF 17 REFERENCES
21 Centimeter Fluctuations from Cosmic Gas at High Redshifts
- Physics
- 2004
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…
The Spin Temperature and 21 cm Brightness of the Intergalactic Medium in the Pre-Reionization era
- Physics
- 2006
We use numerical hydrodynamical simulations of early structure formation in a ΛCDM universe to investigate the spin temperature and 21 cm brightness of the diffuse intergalactic medium (IGM) prior to…
Detecting the Earliest Galaxies through Two New Sources of 21 Centimeter Fluctuations
- Physics
- 2004
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…
The spin temperature of neutral hydrogen during cosmic pre-reionization
- Physics
- 2005
We re-examine the role of collisions in decoupling the H i 21-cm spin temperature from the cosmic microwave background (CMB). The cross-section for de-exciting the 21-cm transition in collisions with…
A Method for Separating the Physics from the Astrophysics of High-Redshift 21 Centimeter Fluctuations
- Physics
- 2005
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…
Wouthuysen-Field coupling strength and application to high-redshift 21-cm radiation
- Physics
- 2006
The first ultraviolet sources in the universe are expected to have coupled the H I spin temperature to the gas kinetic temperature via scattering in the Lyα resonance (the 'Wouthuysen-Field effect').…
The spin temperature of warm interstellar H I
- Physics
- 2001
Collisional excitation of the 21 cm hyperne transition is not strong enough to thermalize it in warm neutral (\intercloud") interstellar gas, which we show by simultaneously solving the equations of…
Descending from on high: Lyman-series cascades and spin-kinetic temperature coupling in the 21-cm line
- Physics
- 2006
We examine the effect of Lyman-continuum photons on the 21-cm background in the high-redshift Universe. The brightness temperature of this transition is determined by the spin temperature T s , which…
Excitation of the Hydrogen 21-CM Line
- PhysicsProceedings of the IRE
- 1958
The importance of spin temperature for 21-cm line studies is reviewed, and four mechanisms which affect it are studied. Two of the mechanisms, collisions with free electrons and interactions with…
X-ray secondary heating and ionization in quasar emission-line clouds
- Physics
- 1985
Accurate Monte Carlo computations of the X-ray secondary electron heating, ionization, and excitation of H and He gas in interstellar space and in quasar emission-line clouds, are presented. The…