The metal line emission of the intergalactic medium in OWLS

Abstract

I will discuss the possibility to detect the intergalactic medium at different redshift through metal line emission. The diffuse intergalactic gas accounts for most of the baryonic mass in the universe, but is extremely difficult to detect. A number of instruments are being planned to detect emission from the missing baryons, both in the local and in the distant universe, in wavelengths spanning from the optical to the X-rays. I use OWLS, a new suite of hydrodynamical simulations of structure formation that includes a large number of runs with varying physical prescriptions for star formation, feedback, cooling and several other physical processes, to predict the intensity of the emitted flux in a sample of X-ray and UV emission lines at low redshift and in a sample of redshifted rest- frame UV emission lines at z>2. At high redshift a number of lines, among others C III, C IV and O VI, should be detectable in relatively high density regions by upcoming optical instruments such as the Cosmic Web Imager.