The 21 cm cosmology and cosmic reionization simulations

The epoch of reionization is a period in the history of the Universe during which the intergalactic hydrogen gas went from neutral to ionized when the Universe was a few hundred million to a billion years old (corresponding to the redshift 6<z<30). This event was powered by the emergence of the first luminous objects from which energetic ultraviolet and X-ray photons were released to ionize the surrounding intergalactic medium. Associated with this process is a rich set of astrophysical processes, the competition of which derives the characteristic rises and falls in the signal of 21-cm brightness temperature as a function of the observed frequency. Detection of these characteristics through 21-cm observations will flag the formation time of the first luminous objects, and provide unique constraints on their physical conditions at the early universe. After a brief review on the current status of the research on cosmic reionization and 21-cm cosmology, I will report in this talk our recent progress in advancing our capability to model such an intrinsically nonlinear process more efficiently and more robustly, using numerical 3D radiative transfer simulations. 

Speaker: 
Yi Mao (Tsinghua)
Place: 
KIAA-PKU Auditorium
Host: 
Yingjie Peng
Time: 
Thursday, January 5, 2017 - 4:00pm