Low-Redshift Lyman Limit Systems as Diagnostics of Cosmological Inflows and Outflows

Abstract

We use cosmological hydrodynamic simulations with stellar feedback from the FIRE project to study the physical nature of Lyman limit systems (LLSs) at z<1. At these low redshifts, LLSs are closely associated with dense gas structures surrounding galaxies, such as galactic winds, dwarf satellites, and cool inflows from the intergalactic medium. Our analysis is based on 14 zoom-in simulations covering the halo mass range M_h~10^9-10^13 Msun at z=0, which we convolve with the dark matter halo mass function to produce cosmological statistics. We find that the majority of cosmologically-selected LLSs are associated with halos in the mass range 10^10 < M_h < 10^12 Msun. The incidence and HI column density distribution of simulated absorbers with columns 10^16.2 < N_HI < 2x10^20 cm^-2 are consistent with observations. High-velocity outflows (with radial velocity exceeding the halo circular velocity by a factor >~2) tend to have higher metallicities ([X/H] ~ -0.5) while very low metallicity ([X/H] < -2) LLSs are typically associated with gas infalling from the intergalactic medium. However, most LLSs occupy an intermediate region in metallicity-radial velocity space, for which there is no clear trend between metallicity and radial kinematics. Metal-enriched inflows arise in the FIRE simulations as a result of galactic winds that fall back onto galaxies at low redshift. The overall simulated LLS metallicity distribution has a mean (standard deviation) [X/H] = -0.9 (0.4) and does not show significant evidence for bimodality, in contrast to recent observational studies but consistent with LLSs arising from halos with a broad range of masses and metallicities.

13 pages, 12 figures. Accepted to MNRAS

References in corpus (13)

• Cold streams in early massive hot haloes as the main mode of galaxy formation
• A New Calculation of the Ionizing Background Spectrum and the Effects of HeII Reionization
• Cosmological Simulations of Intergalactic Medium Enrichment from Galactic Outflows
• Ubiquitous outflows in DEEP2 spectra of star-forming galaxies at z=1.4
• On the (Non)Evolution of HI Disks over Cosmic Time
• Metal flows of the circumgalactic medium, and the metal budget in galactic halos
• Neutral hydrogen in galaxy halos at the peak of the cosmic star formation history
• A large population of metal-rich, compact, intergalactic C IV absorbers - Evidence for poor small-scale metal mixing
• Through Thick and Thin - HI Absorption in Cosmological Simulations
• The Cosmic Evolution of the Metallicity Distribution of Ionized Gas Traced by Lyman Limit Systems
• The properties of the cool circumgalactic gas probed with the SDSS, WISE and GALEX surveys
• Low-metallicity Absorbers Account for Half of the Dense Circumgalactic Gas at z < 1
• Lyman Limit Systems in Cosmological Simulations

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