Speaker
Description
The cosmic 21-cm signal provides a powerful window into the unseen galaxies that shaped the thermal and ionization history of the intergalactic medium (IGM), the reservoir of neutral hydrogen responsible for the emission itself. At present, the Murchison Widefield Array (MWA) stands among the leading low-frequency interferometers dedicated to this pursuit, alongside LOFAR and HERA. While HERA currently delivers the most stringent upper limits on the 21-cm power spectrum, MWA's wide field of view and mature calibration pipeline make it uniquely suited for robust statistical studies and cross-validation across independent experiments.
Using the latest MWA observations, complemented by existing HERA constraints, our study performs a comprehensive Bayesian inference analysis capable of forward-modeling full 4D realizations of the cosmic 21-cm lightcone. Combined with complementary galaxy and CMB observations, our results reveal statistical evidence suggesting that the IGM experienced partial heating in the early Universe. If this heating is attributed to galaxies and their high-mass X-ray binaries, their luminosities must exceed those observed in the local Universe, hinting at a potentially significant contribution from metal-free Population III stars.
| Timeslot preferences | I've registered as a remote participant but happy to attend in person if that's needed for a talk. |
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