Numerical simulations of the Warm-Hot Intergalactic Medium

Abstract

In this paper we review the current predictions of numerical simulations for the origin and observability of the warm hot intergalactic medium (WHIM), the diffuse gas that contains up to 50 per cent of the baryons at z~0. During structure formation, gravitational accretion shocks emerging from collapsing regions gradually heat the intergalactic medium (IGM) to temperatures in the range T~10^5-10^7 K. The WHIM is predicted to radiate most of its energy in the ultraviolet (UV) and X-ray bands and to contribute a significant fraction of the soft X-ray background emission. While O VI and C IV absorption systems arising in the cooler fraction of the WHIM with T~10^5-10^5.5 K are seen in FUSE and HST observations, models agree that current X-ray telescopes such as Chandra and XMM-Newton do not have enough sensitivity to detect the hotter WHIM. However, future missions such as Constellation-X and XEUS might be able to detect both emission lines and absorption systems from highly ionised atoms such as O VII, O VIII and Fe XVII.

18 pages, 5 figures, accepted for publication in Space Science Reviews, special issue "Clusters of galaxies: beyond the thermal view", Editor J.S. Kaastra, Chapter 14; work done by an international team at the International Space Science Institute (ISSI), Bern, organised by J.S. Kaastra, A.M. Bykov, S. Schindler & J.A.M. Bleeker

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• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• The Search for the Missing Baryons at Low Redshift
• Magnetic Field Seeding by Galactic Winds
• Simulation techniques for cosmological simulations
• Cosmological shock waves
• The Santa Fe Light Cone Simulation Project: I. Confusion and the WHIM in Upcoming Sunyaev-Zel'dovich Effect Surveys
• FUV and X-ray absorption in the Warm-Hot Intergalactic Medium
• Soft X-ray and extreme ultraviolet excess emission from clusters of galaxies
• X-Ray Emission from the Warm Hot Intergalactic Medium
• Future instrumentation for the study of the Warm-Hot Intergalactic Medium
• Constrain intergalactic medium from the SZ effect map

Cited by in corpus (5)

• A Semi-Analytic Model for the Co-evolution of Galaxies, Black Holes, and Active Galactic Nuclei
• The effect of photo-ionization on the cooling rates of enriched, astrophysical plasmas
• Absorption signatures of warm-hot gas at low redshift: OVI
• FUV and X-ray absorption in the Warm-Hot Intergalactic Medium
• Clusters of galaxies: setting the stage