Institute for Advanced Study/Princeton University Early Universe/Cosmology Lunch Discussion

The galaxies are biased tracers of large-scale structure, which usually form around the peaks of the density field. To probe the baryon in less dense regions, we deploy density mapping techniques combining different tracers. In this talk, I will introduce two key projects from our group: the Lyman alpha tomography (CLAMATO) and FRB Foreground mapping (FLIMFLAM).

In the first part, I will introduce our discovery of a special galaxy protocluster through cross-matching density maps from galaxy tracers and Lyman alpha tracers. Though absent from the Lyman alpha map in the CLAMATO survey, the protocluster was confirmed to be a progenitor of a 10^14 solar mass cluster based on the surrounding galaxy distribution. Simulation analysis on similar protoclusters suggests that the large-scale gas heating due to galaxy feedback is a plausible mechanism for such protocluster.

In the second part, I will briefly introduce our group's ongoing FLIMFLAM project. Using FLIMFLAM, we measure how different components along the line-of-sight contribute to the dispersion measure (DM) of Fast Radio Bursts (FRBs). Through the ARGO density mapping framework, FLIMFLAM has established the first-ever constraints on the relative fractions of cosmic baryons in the IGM and CGM using 9 localized FRBs. Finally, I will present preliminary results from MaiGO, an upgraded version of ARGO that I am developing.