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The shocking history of the early Universe and the formation of the first cosmic structures

Event Details

Event Dates: 

Friday, September 14, 2012 - 6:00am

Speaker Name(s): 

Ryan O'Leary

Speaker Affiliation(s): 

UC, Berkeley
Seminar Type/Subject

Event Details & Abstract: 

Recently, Tseliakhovich and Hirata (2010) showed that during the cosmic Dark Ages the baryons were typically moving supersonically with respect to the dark matter. I will describe how such supersonic motion sources bow shocks and Mach cones around the first halos, which act to erase the velocity difference in overdense gas. I will show the results of numerical simulations that are the first to self consistently incorporate the dark matter-baryon velocity offset, and how it impacts the formation of the first stars and mini-halos. Finally, I will disucss the impact of the velocity differential on redshifted 21cm radiation from the epoch of first light.