English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We present a new cosmological zoom-in simulation, where the zoom regionconsists of two halos with virial mass M_v~5x10^{12}M_{sun} and a ~Mpc longcosmic filament connecting them at z~2. Using this simulation, we study theevolution of the intergalactic medium in between these two halos atunprecedented resolution. At 5>z>3, the two halos are found to lie in a largeintergalactic sheet, or "pancake", consisting of multiple co-planar densefilaments along which nearly all halos with M_v>10^9M_{sun} are located. Thissheet collapses at z~5 from the merger of two smaller sheets. The strong shockgenerated by this merger leads to thermal instabilities in the post-shockregion, and to a shattering of the sheet resulting in <~kpc scale clouds withtemperatures of T>~2x10^4K and densities of n>~10^{-3}cm^{-3}, which arepressure confined in a hot medium with T~10^6K and n>~10^{-5}cm^{-3}. When thesheet is viewed face on, these cold clouds have neutral hydrogen columndensities of N_{HI}>10^{17.2}cm^{-2}, making them detectable as Lyman limitsystems, though they lie well outside the virial radius of any halo and evenwell outside the dense filaments. Their chemical composition is pristine,having zero metalicity, similar to several recently observed systems. Sincethese systems form far from any galaxies, these results are robust to galaxyformation physics, resulting purely from the collapse of large scale structureand radiative cooling, provided sufficient spatial resolution is available.

Shattering of Cosmic Sheets due to Thermal Instabilities: a Formation Channel for Metal-Free Lyman Limit Systems