School of Physics and Astronomy

Astronomy Unit Seminar - Evaluating Cosmic Dawn

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15 February 2019

Time: 2:31 - 3:30pm
Speaker: Anastasia Fialkov
Venue: GO Jones 610

Cosmic dawn is one of the least-explored epochs in the history of the Universe illuminated by the very first stars and black holes. One of the potentially powerful probes of cosmic dawn is the predicted 21-cm signal of neutral intergalactic hydrogen. The 21-cm signal is tied to the intensity of radiation generated by the first sources of light, and, thus, can be used to constrain process of primordial star and black hole formation as well as reionizationIn my talk I will discuss first observational constraints on this epoch (redshifts z~6-14) established using global 21-cm experiments. Pioneering radio experiments such as EDGES High-Band and SARAS2 deliver data which are capable of disfavoring large sections of the high-redshift astrophysical parameter space. I will also discuss combined constraints with high-redshift quasars and Lyman Break Galaxies. Finally, I will comment on the claimed discovery of the 21-cm signal from z~17 made with the EDGES Low-Band antenna.