Speaker
Description
The 21 cm hydrogen line is a unique tool that allows scientists to study the vast space between galaxies, known as the intergalactic medium (IGM) and to track how it changed over time as the universe evolved. By measuring tiny fluctuations in this signal, researchers can learn about the temperature and ionisation state of the early universe.
In this talk, we present the deepest limits ever achieved on the 21 cm power spectrum at redshifts z = 6.5, 6.8, and 7, which correspond to a time when the universe was just a few hundred million years old. These results are based on ten years of observations with the Murchison Widefield Array (MWA), collected between 2013 and 2023. Of the total 657 hours of data, a carefully selected 268-hour subset was used for the final analysis, following advanced techniques to remove interference from brighter foreground sources. These results offer the first evidence that the IGM was already heating up during this crucial stage in cosmic history.
| Timeslot preferences | 20 min |
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