Papers › NeutralUniverseMachine: An Empirical Model for the Evolution of HI and H₂ Gas in the Universe
NeutralUniverseMachine: An Empirical Model for the Evolution of HI and H₂ Gas in the Universe
Hong Guo, Jing Wang, Michael G. Jones, Peter Behroozi
The archive published only this paper's code-link row. Authors, date and abstract are from arXiv's metadata (CC0), read from the Kaggle arXiv metadata snapshot of 2026-09-12 where its title matched the archive's; the title is the archive's.
Accurately modeling the cold gas content in the universe is challenging for current theoretical models. We propose a new empirical model NeutralUniverseMachine for the evolution of HI and H₂ gas along with dark matter halos based on the UniverseMachine catalog. It is able to accurately describe the observed HI and H₂ mass functions, molecular-to-atomic ratio, HI-halo mass relation, HI/H₂-stellar mass relations at z∼0, as well as the evolution of cosmic gas densities ρ_(HI) and ρ_(H₂) in 0<z<6. The predictions from our model include: (i) There is weak evolution of HI mass function in 0<z<3, but the evolution of H₂ mass function is much stronger at the massive end. (ii) The average HI and H₂ masses at a given stellar mass decrease by around 1 dex since z=3 for the star-forming galaxies, but the evolution for the quenched galaxies is much weaker. (iii) Star-forming galaxies have varying HI depletion time τ_(HI) from 0.1 Gyr to 10 Gyr, and the dependence of τ_(HI) on stellar mass and redshift is much stronger than those of H₂ depletion time. The quenched galaxies have much longer gas depletion time and weaker redshift evolution. (iv) The cosmic baryon density associated with galaxies is dominated by stars for z<1.2 and mainly contributed by HI gas at higher redshifts. (v) The HI bias gradually increases with the redshift from 0.69 to 2.33 in 0<z<3 and is consistent with recent HI intensity mapping experiments.
Code
Repository list and official/mentioned flags are the archive's, frozen 2025-07-28. Reachability, where shown, is from one Syntology probe window (2026-09-16 to 2026-09-18); repositories not probed show nothing. GitHub stars are not tracked.
Code Syntology ran Syntology
Not run by Syntology. Nothing on this page verifies that the listed code works.
Results from the paper archive 2025-07-28
No leaderboard rows for this paper in the archive.
Report a problem or propose a change · a person checks every report against the paper or source before anything changes; decisions are listed on /corrections