Will Nonlinear Peculiar Velocity and Inhomogeneous Reionization Spoil 21 cm Cosmology from the Epoch of Reionization?
The 21 cm background from the epoch of reionization is a promising cosmological probe: line-of-sight velocity fluctuations distort redshift, so brightness fluctuations in Fourier space depend upon angle, which linear theory shows can separate cosmological from astrophysical information. Nonlinear fluctuations in ionization, density, and velocity change this, however. The validity and accuracy of the separation scheme are tested here for the first time, by detailed reionization simulations. The scheme works reasonably well early in reionization (≲40% ionized), but not late (≳80% ionized).
Physical Review Letters
- Pub Date:
- April 2013
- Observational cosmology;
- Mathematical procedures and computer techniques;
- HI regions and 21-cm lines;
- diffuse translucent and high-velocity clouds;
- Astrophysics - Cosmology and Extragalactic Astrophysics;
- Astrophysics - Instrumentation and Methods for Astrophysics
- 2 figures, matches published PRL version