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

In this work, I investigate the properties of Lyman limit systems (LLSs)using state-of-the-art zoom-in cosmological galaxy formation simulations withon the fly radiative transfer, which includes both the cosmic UV background(UVB) and local stellar sources. I compare the simulation results toobservations of the incidence frequency of LLSs and the HI column densitydistribution function over the redshift range $z=2-5$ and find good agreement.I explore the connection between LLSs and their host halos and find that LLSsreside in halos with a wide range of halo masses with a nearly constantcovering fraction within a virial radius. Over the range $z=2-5$, I find thatmore than half of the LLSs reside in halos with $M < 10^{10}h^{-1}M_\odot$,indicating that absorption line studies of LLSs can probe these low-massgalaxies which H$_2$-based star formation models predict to have very littlestar formation. I study the physical state of individual LLSs and test a simplemodel (Schaye 2001) which encapsulates many of their properties. I confirm thatLLSs have a characteristic absorption length given by the Jeans length and thatthey are in photoionization equilibrium at low column densities. Finally, Iinvestigate the self-shielding of LLSs to the UVB and explore how thenon-sphericity of LLSs affects the photoionization rate at a given $N_{\rmHI}$. I find that at $z\approx 3$, LLSs have an optical depth of unity at acolumn density of $\sim 10^{18} {\rm cm}^{-2}$ and that this is the columndensity which characterizes the onset of self-shielding.

Investigating the Physics and Environment of Lyman Limit Systems in Cosmological Simulations