Detecting the Rise and Fall of 21 cm Fluctuations with the Murchison Widefield Array

Understand

We forecast the sensitivity with which the Murchison Widefield Array (MWA) can measure the 21 cm power spectrum of cosmic hydrogen, using radiative transfer simulations to model reionization and the 21 cm signal.

• The MWA is sensitive to roughly a decade in scale (wavenumbers of k ~ 0.1 - 1 h Mpc^{-1}), with foreground contamination precluding measurements on larger scales, and thermal detector noise limiting the small scale sensitivity.
• This amounts primarily to constraints on two numbers: the amplitude and slope of the 21 cm power spectrum on the scales probed.
• We find, however, that the redshift evolution in these quantities can yield important information about reionization.