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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Atomic hydrogen (HI) serves a crucial role in connecting galactic-scaleproperties such as star formation with the large-scale structure of theUniverse. While recent numerical simulations have successfully matched theobserved covering fraction of HI near Lyman Break Galaxies (LBGs) and in theforeground of luminous quasars at redshifts $z \lesssim 3$, the low-mass endremains as-of-yet unexplored in observational and computational surveys. Weemploy a cosmological, hydrodynamical simulation (FIREbox) supplemented withzoom-in simulations (MassiveFIRE) from the Feedback In Realistic Environments(FIRE) project to investigate the HI covering fraction of Lyman Limit Systems($N_{\mathrm{HI}} \gtrsim 10^{17.2}$ cm$^{-2}$) across a wide range ofredshifts ($z=0-6$) and halo masses ($10^8-10^{13} M_{\odot}$ at $z=0$,$10^8-10^{11} M_{\odot}$ at $z=6$) in the absence of feedback from activegalactic nuclei (AGN). We find that the covering fraction inside haloesexhibits a strong increase with redshift, with only a weak dependence on halomass for higher-mass haloes. For massive haloes ($M_{\mathrm{vir}} \sim10^{11}-10^{12} M_{\odot}$), the radial profiles showcase scale-invariance andremain independent of mass. The radial dependence is well-captured by a fittingfunction. The covering fractions in our simulations are in good agreement withmeasurements of the covering fraction in LBGs. Our comprehensive analysisunveils a complex dependence with redshift and halo mass for haloes with$M_{\mathrm{vir}} \lesssim 10^{10} M_{\odot}$ that future observations aim toconstrain, providing key insights into the physics of structure formation andgas assembly.

The HI covering fraction of Lyman Limit Systems in FIRE haloes