Speaker
Description
We present a cosmological zoom-in simulation of two 5x10^12 halos and a Mpc-long cosmic filament connecting them at z∼2, to study the evolution of the IGM and the cosmic web around this system at unprecedented resolution. At 5>z>3, the halos lie in a cosmic sheet with multiple coplanar filaments which contain most of the halos. The collapse of the sheet at z∼5 generates a strong shock that leads to thermal instabilities, shattering, and a multiphase medium of kpc-scale cold clouds pressure confined in a hot medium. These clouds are detectable as LLSs, though they lie well outside halos or filaments. They are metal-free, similar to several recently observed systems. This effect is unresolved in state-of-the-art cosmological simulations, which underestimate the HI content of the cosmic web.
