UV background fluctuations traced by metal ions at $z\approx 3$

Abstract

Here we investigate how LyC-opaque systems present in the intergalactic medium at $z\approx 3$ can distort the spectral shape of a uniform UV background (UVB) through radiative transfer (RT) effects. With this aim in mind, we perform a multi-frequency RT simulation through a cosmic volume of $10h^{-1}$~cMpc scale polluted by metals, and self-consistently derive the ions of all the species. The UVB spatial fluctuations are traced by the ratio of He$\mathrm{II}$ and H$\mathrm{I}$ column density, $\eta$, and the ratio of C$\mathrm{IV}$ and Si$\mathrm{IV}$ optical depths, $\zeta$. We find that: (i) $\eta$ spatially fluctuates through over-dense systems ($\Delta$) with statistically significant deviations $\delta \eta >25$\% in 18\% of the volume ; (ii) same fluctuations in $\zeta$ are also present in $34$\% of the enriched domain (only 8\% of the total volume) and derive from a combination of RT induced effects and in-homogeneous metal enrichment, both effective in systems with $\Delta >1.5$.

arXiv commentAccepted for pub. in MNRAS after very minor rev

References in corpus (36)

• The cosmological simulation code GADGET-2
• Radiative Transfer in a Clumpy Universe: II. The Utraviolet Extragalactic Background
• Radiative transfer in a clumpy universe: IV. New synthesis models of the cosmic UV/X-ray background
• Line formation in solar granulation: IV. [O I], OI and OH lines and the photospheric O abundance
• Evolution of the Ionizing Background and the Epoch of Reionization from the Spectra of z~6 Quasars
• P3M-SPH simulations of the Lyman-alpha Forest
• Chemical enrichment of galaxy clusters from hydrodynamical simulations
• The Physics of the Intergalactic Medium
• Metal Enrichment and Ionization Balance in the Lyman $\alpha$ Forest at $z=3$
• The transition from population III to population II-I star formation
• The High-Redshift He II Gunn-Peterson Effect: Implications and Future Prospects
• The Metagalactic Ionizing Radiation Field at Low Redshift
• A Study of the Reionization History of Intergalactic Helium with FUSE and VLT
• Metallicity of the intergalactic medium using pixel statistics: III. Silicon
• The Redshift Evolution of the Metagalactic Ionizing Flux Inferred from Metal Line Ratios in the Lyman Forest
• The Fluctuating Intergalactic Radiation Field at Redshifts z = 2.3-2.9 from He II and H I Absorption towards HE 2347-4342
• Resolving the Helium Lyman-$\alpha$ Forest: Mapping Intergalactic Gas and Ionizing Radiation at $z\approx 3$
• The Influence of the Photoionizing Radiation Spectrum on Metal-Line Ratios in Ly alpha Forest Clouds
• The effect of intergalactic helium on hydrogen reionisation: implications for the sources of ionising photons at z > 6
• Spatial fluctuations in the spectral shape of the UV background at 2<z<3 and the reionization of helium
• The evolution of the physical state of the IGM
• Radiative Transfer Effects on the Lya Forest
• The transverse proximity effect in spectral hardness on the line of sight towards HE 2347-4342
• Spectral shape of the UV ionizing background and HeII absorption at redshifts 1.8 < z < 2.9
• CRASH3: cosmological radiative transfer through metals
• The impact of helium reionization on the structure of the intergalactic medium
• The Implications of Gunn-Peterson Troughs in the HeII Lyman-alpha Forest
• Spectral energy distribution of the metagalactic ionizing radiation field from QSO absorption spectra
• The Effect of Fluctuations on the Helium-Ionizing Background
• A self-consistent 3D model of fluctuations in the helium-ionizing background
• The case against large intensity fluctuations in the z ~ 2.5 HeII Lyman-alpha forest
• Fluctuations of the intergalactic UV background towards two lines of sight
• The impact of spatial fluctuations in the ultra-violet background on intergalactic carbon and silicon
• X-ray ionization of the intergalactic medium by quasars
• HST Spectral Observations near the He II Ly-alpha Break: Implications for He II Reionization
• Quasar spectral energy distribution in EUV restored from associated absorbers: indications to the HeII opacity of the quasar accretion disk wind

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• Probing Inhomogeneity in the Helium Ionizing UV Background
• The dust-star interplay in late-type galaxies at z < 0.5: forecasts for the JWST