• Den Herder, Jan-Willem
• Paerels, Frits B. S.
• Bruijn, Marcel
• Rasmussen, Andrew
• Hoevers, Henk
• Kaastra, Jelle S.
• Kahn, Steven M.
• De Korte, Piet A.
• Scharf, Caleb

Abstract

A very significant fraction of the baryonic matter in the local universe is predicted to form a Warm Hot Intergalactic Medium (WHIM) of very low density, moderately hot gas, tracing the cosmic web. Its X-ray emission is dominated by metal features, but is weak (&lt; 0.01 photons/cm<SUP>2</SUP>/s/sr) and potentially hard to separate from the galactic component. However, a mission capable of directly mapping this component of the large scale structure of the universe, via a small number of well chosen emission lines, is now within reach due to recent improvements in cryogenic X-ray detector energy resolution. To map the WHIM, the energy resolution and grasp are optimized. A number of missions have been proposed to map the missing baryons including MBE (US/SMEX program) and DIOS (Japan). The design of the mirror and detector have still room for improvements which will be discussed. With these improvements it is feasible to map a 10 x 10 degree area of the sky in 2 years out to z = 0.2 with sufficient sensitivity to directly detect WHIM structure, such as filaments connecting clusters of galaxies. This structure is predicted by the current Cold Dark Matter paradigm which thus far appears to provide a good description of the distribution of matter as traced by galaxies. <P />...

Topics

• density
• impedance spectroscopy
• cluster