Properties of cosmological filaments extracted from Eulerian simulations

Abstract

Using a new parallel algorithm implemented within the VisIt framework, we analysed large cosmological grid simulations to study the properties of baryons in filaments. The procedure allows us to build large catalogues with up to ∼ 3 · 10 4 filaments per simulated volume and to investigate the properties of cosmic filaments for very large volumes at high resolution (up to 300 3 Mpc 3 simulated with 2048 3 cells). We determined scaling relations for the mass, volume, length and temperature of filaments and compared them to those of galaxy clusters. The longest filaments have a total length of about 200 Mpc with a mass of several 10 15 M . We also investigated the effects of different gas physics. Radiative cooling significantly modifies the thermal properties of the warm-hot-intergalactic medium of filaments, mainly by lowering their mean temperature via line cooling. On the other hand, powerful feedback from active galactic nuclei in surrounding halos can heat up the gas in filaments. The impact of shock-accelerated cosmic rays from diffusive shock acceleration on filaments is small and the ratio of between cosmic ray and gas pressure within filaments is of the order of ∼ 10 − 20 percent.

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

“…Colberg et al 2005). Our recent analysis of the gas properties of the filaments in large cosmological simulations showed that up to ∼10 3 filaments can be identified in (100 Mpc) 3 at z = 0, with a decreasing powerlaw distribution of lengths from one Mpc up to several tens of Mpc (Gheller et al, 2015). Deep imaging of the region between close pairs of galaxy clusters is potentially an efficient way to search for cosmic filaments, even if in such close configurations it might be difficult to separate the emission from cluster accretion shocks and filaments shocks.…”

Baryonic Processes in the Large-Scale Structuring of the Universe

“…Thus, in essence, the outcome of these processes is that gravitational collapse naturally produces a filamentary topology, which accounts for the overall topology of the cosmic web on the largest scales, revealed both by numerical simulations and observations (e.g. Klypin & Shandarin, 1983;Van de Weygaert & Bond, 2008;Klar & Mücket, 2010;Eckert et al, 2015;Gheller et al, 2015). Note that sheets and filaments of matter appear in many other Astrophysical contexts too.…”

A comparison of cosmological filaments catalogues

“…There are works that are based on visual inspection (Akamatsu et al 2017), identification of regions inter-clusters (Pimbblet et al 2004;Colberg et al 2005), or on a random configuration of galaxies based on a modelled probability distribution (Tempel et al 2014a). There are even post-processing algorithms that look for iso-densities surfaces of gas in simulations (Gheller et al 2015).…”