Forecasts for the detection of the magnetised cosmic web from cosmological simulations

TL;DR

This paper uses cosmological simulations to evaluate the potential of upcoming radio surveys to detect the magnetised cosmic web through synchrotron emission, highlighting the importance of filament magnetisation levels.

Contribution

It introduces models of radio emission from the cosmic web based on 3D simulations and assesses detection prospects for major radio surveys.

Findings

LOFAR, SKA1-LOW, and MWA could detect the cosmic web if filament magnetisation is around 1% of thermal energy.

Simulations show the detectability depends critically on the magnetic field strength in filaments.

The study provides guidelines for future observational strategies to detect the cosmic web.

Abstract

The cosmic web contains a large fraction of the total gas mass in the universe but is difficult to detect at most wavelengths. Synchrotron emission from shock-accelerated electrons may offer the chance of imaging the cosmic web at radio wavelengths. In this work we use 3D cosmological ENZO-MHD simulations (combined with a post-processing renormalisation of the magnetic field to bracket for missing physical ingredients and resolution effects) to produce models of the radio emission from the cosmic web. In post-processing we study the capabilities of 13 large radio surveys to detect this emission. We find that surveys by LOFAR, SKA1-LOW and MWA have a chance of detecting the cosmic web, provided that the magnetisation level of the tenuous medium in filaments is of the order of 1% of the thermal gas energy.