Speaker
Description
Distinguishing between different reionisation histories requires observables that are sensitive to the timing and morphology of the Epoch of Reionization (EoR). We present a method to reconstruct redshift-dependent line-of-sight velocity fields from the 21-cm signal and use them to construct patchy kinematic Sunyaev--Zel'dovich (kSZ) maps that can be cross-correlated with the observed kSZ signal. Unlike approaches that square the kSZ field to remove velocity sign cancellations, our method preserves directional phase information, enabling a first-order cross-correlation. As reionization progresses, this cross-correlation changes sign when ionisation fluctuations begin to dominate the 21-cm signal. The evolution of the cross-correlator at $\ell = 3000$ distinguishes between different EoR models. This proof-of-concept study demonstrates that 21-cm based kSZ reconstruction provides a promising avenue for probing the timing and duration of the EoR.
| Other topic / keywords: | 21-cm, kSZ, Epoch of Reionization |
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