Oral Presentation

High Redshift Protoclusters as Drivers of Cosmic Star Formation and the Cosmic Hot Gas Content

Author(s): Yi-Kuan Chiang (Johns Hopkins University)

Presenter: Yi-Kuan Chiang (Johns Hopkins University)

Thanks to HSC, PFS and other facilities, large statistical studies of galaxy protoclusters are becoming feasible for the first time. Meanwhile, cosmological simulations and mocked observations are also playing an increasingly important role in identifying potential science and assisting survey planning. I will show that protocluster galaxies are expected to be a dominant population that drives the cosmic star formation history at high redshift, providing nearly 50% percent of the ionizing photons during the epoch of reionization. On the other hand, the gas feeding halos hosting individual protocluster galaxies are among the first to be shocked heated followed by a long cooling timescale. This hot gas content is potentially observable via the thermal Sunyaev–Zel'dovich (tSZ) effect most likely first in cross-correlation analyses. I will show some results on the cosmic tSZ signal as a function of redshift and discuss its origin in the context of cosmic structure formation.