Detecting the Cosmic Web: Lyα Emission from Simulated Filaments at z=3

Abstract

The standard cosmological model ($\Lambda$CDM) predicts the existence of the cosmic web: a distribution of matter into sheets and filaments connecting massive halos. However, observational evidence has been elusive due to the low surface brightness of the filaments. Recent deep MUSE/VLT data and upcoming observations offer a promising avenue for Ly$\alpha$ detection, motivating the development of modern theoretical predictions. We use hydrodynamical cosmological simulations run with the AREPO code to investigate the potential detectability of large-scale filaments, excluding contributions from the halos embedded in them. We focus on filaments connecting massive ($M_{200c}\sim (1-3)\times 10^{12}{M}_{\odot }$) halos at z=3, and compare different simulation resolutions, feedback levels, and mock-image pixel sizes. We find increasing simulation resolution does not substantially improve detectability notwithstanding the intrinsic enhancement of internal filament structure. By contrast, for a MUSE integration of 31 hours, including feedback increases the detectable area by a factor of $\simeq$5.5 on average compared with simulations without feedback, implying that even the non-bound components of the filaments have substantial sensitivity to feedback. Degrading the image resolution from the native MUSE scale of (0.2")${}^2$ per pixel to (5.3")${}^2$ apertures has the strongest effect, increasing the detectable area by a median factor of $\simeq$200 and is most effective when the size of the pixel roughly matches the width of the filament. Finally, we find the majority of Ly$\alpha$ emission is due to electron impact collisional excitations, as opposed to radiative recombination.

References in corpus (16)

• Cold streams in early massive hot haloes as the main mode of galaxy formation
• Simulating galaxy formation with black hole driven thermal and kinetic feedback
• The Auriga Project: the properties and formation mechanisms of disc galaxies across cosmic time
• Time-Dependent Ionization in Radiatively Cooling Gas
• The MUSE Hubble Ultra Deep Field Survey: I. Survey description, data reduction and source detection
• Bimodal gas accretion in the Horizon-MareNostrum galaxy formation simulation
• Quasar Quartet Embedded in Giant Nebula Reveals Rare Massive Structure in Distant Universe
• Evolution of the Intergalactic Opacity: Implications for the Ionizing Background, Cosmic Star Formation, and Quasar Activity
• A Population of Faint Extended Line Emitters and the Host Galaxies of Optically Thick QSO Absorption Systems
• Gas filaments of the cosmic web located around active galaxies in a proto-cluster
• Lyman alpha Resonant Scattering in Young Galaxies - Predictions from Cosmological Simulations
• Inspiraling Halo Accretion Mapped in Lyman-$\alpha$ Emission around a $z\sim 3$ Quasar
• Lyman alpha Radiative Transfer in Cosmological Simulations using Adaptive Mesh Refinement
• Stacking the Cosmic Web in Fluorescent Lyman alpha Emission with MUSE
• Ly$\alpha$ view around a z=2.84 hyperluminous QSO at a node of the cosmic web
• Variations in the slope of the resolved star-forming main sequence: a tool for constraining the mass of star-forming regions

Cited by in corpus (5)

• The MUSE Extremely Deep Field: the Cosmic Web in Emission at High Redshift
• Rivers of Gas I.: Unveiling The Properties of High Redshift Filaments
• The cosmic web in Lyman-alpha emission
• Probing the Diffuse Lyman-alpha Emission on Cosmological Scales: Lyα Emission Intensity Mapping Using the Complete SDSS-IV eBOSS Survey
• Prospects for detecting cosmic filaments in Lyman-alpha emission across redshifts $z=2-5$