Properties of cosmological filaments extracted from Eulerian simulations

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 × 10⁴ filaments per simulated volume and to investigate the properties of cosmic filaments for very large volumes at high resolution (up to 300³ Mpc³ simulated with 2048³ 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 10¹⁵M<inf>⊙</inf>. 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 haloes can heat up the gas in filaments. The impact of shockaccelerated cosmic rays from diffusive shock acceleration on filaments is small and the ratio between cosmic ray and gas pressure within filaments is of the order of ~10-20 percent.