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∼105 107 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∼105 105.5 K are seen in FUSE and Hubble Space Telescope 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.
- Publication:
-
Space Science Reviews
- Pub Date:
- February 2008
- DOI:
- 10.1007/s11214-008-9318-3
- arXiv:
- arXiv:0801.1039
- Bibcode:
- 2008SSRv..134..295B
- Keywords:
-
- Large-scale structure of the universe;
- Intergalactic medium;
- Diffuse radiation;
- X-rays: diffuse background;
- Quasars: absorption lines;
- Astrophysics
- E-Print:
- 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