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OATS-DAUT SEMINAR
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Speaker: Enzo Branchini (University of Roma Tre)

Title: Looking for missing barions with x-ray glasses

Date: Wednesday, March 7th, 2007
Time: 12:00
Venue: Villa Bazzoni

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Abstract: Several independent observations indicate that not only a large fraction of the mass-energy density in the Universe is "dark" but also that ~ 50% of the "luminous" matter is missing in the local universe. Theoretical models based on hydrodynamical simulations suggest that this missing light is in the from of diffuse gas with temperature in the range (105 K - 107 K) that trace the sheets and the filaments of the cosmic web. The best chance of detecting this warm hot component of the intergalactic medium is by observing the x-ray emission or absorption lines of highly ionized metals like OVII or OVIII. These measurements, however, are at the limit of current instrumentation and, perhaps not surprisingly, no unambiguous detection has been obtained so far. In this seminar I will discuss the possibility of detecting WHIM either in emission or in absorption, trace its thermal history and spatial distribution using the next generation X-ray satellites.
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