Sarah Bosman, MPIA

Quasars in the Early Universe: Insights into Large-Scale-Structure and the First Galaxies

Over 200 bright quasars have now been discovered in the first billion years of the Universe, with this number set to explode again with the now-online Euclid space mission. Observations of the first quasars, serving as "back-lights", have revolutionised our understanding of large-scale-structure at early times. In particular, our picture of hydrogen reionisation has been completely re-written. This process, during which intergalactic hydrogen becomes ionised by the light of the first stars, has broken every expectation: it ends much later (z~5.3), is far more inhomogeneous, and is far clumpier on small scales than all models had predicted. In this talk, I will present these surprising results obtained in the last 3 year by the XQR-30 Large Program, and their unexpected consequences on the inferred properties of the first galaxies.

https://uni-hamburg.zoom.us/j/66006535328?pwd=aGkrSjJIYmZjK0VpYlpGL0ZrdHg2UT09

Meeting ID: 660 0653 5328

Passcode: 20658852