Colloquium: Laura Keating (AIP)
Constraining the history of reionization with quasar absorption lines
The epoch of reionization marks the last major phase transition of the Universe, when photons emitted by the first structures ionized and heated the gas surrounding them. A complete understanding of reionization would reveal the properties of the first stars and galaxies, as well as increasing the precision to which the high-redshift intergalactic medium can be used as a cosmological probe. In this talk I will present results from radiative transfer simulations of cosmic reionization, which were carefully calibrated to reproduce the mean flux of the Lyman-alpha forest below redshift 6. I will show that matching the observed mean flux and long (> 100 Mpc) absorption troughs requires reionization to have ended later than previously thought, with islands of neutral hydrogen still found below redshift 5.5. I will demonstrate that future observations of high redshift quasars have the potential to constrain the entire latter half of reionization from quasar absorption line data alone.
Feb. 25, 2021, 2:30 p.m. – 3:30 p.m.
Colloquium Zoom room