University of Connecticut

Events Calendar

Astronomy Seminar

Wednesday, October 17, 2018
2:00pm – 3:00pm

Storrs Campus
Gant West 121

Dr. Charlotte A. Mason, Harvard-Smithsonian Center for Astrophysics

What Can Galaxies Tell Us About Reionization

The reionization of intergalactic hydrogen in the universe's first billion years was likely driven by the first stars and galaxies. The timeline of reionization is currently uncertain but if it is accurately measured it can unveil the properties of 'first light' sources. Lyman alpha (Lyα) emission from galaxies can potentially probe the intergalactic medium (IGM) at high redshifts but requires modeling physics from pc to Gpc scales. I will introduce a new forward-modeling framework which combines cosmological IGM simulations with interstellar medium models to enable Bayesian inference of the IGM neutral hydrogen fraction from observations of Lyα from galaxies. I will present our new measurements of the neutral fraction at z~7 and z~8 and place them in the context of the reionization history. I will describe ongoing efforts with the HST survey GLASS to build larger spectroscopic samples of galaxies at z>6 to further measure the reionization timeline, and future prospects with JWST.


Prof. K. Whitaker

Physics Department (primary)

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