Temperature, metal abundance and cosmological density of the WHIM from FUV and X-ray absorption lines

We propose the analysis of a sample of 16 bright X-ray sources with LETG data and FUV spectroscopy, to study the warm-hot intergalactic medium (WHIM) towards these sources. This project will be the first multi-wavelength (FUV and X-rays) study of the WHIM, and will provide significant advances in the characterization of the WHIM (both temperature and abundance) and its cosmological density. Unique features of this project are: (1) use of a new method to identify filaments from galaxy redshift surveys; (2) combination of FUV and X-ray data to provide superior constraints on both temperature and abundance of the WHIM; (3) a large number of sources with high quality Chandra and XMM spectra to provide an accurate measurement of Omega_WHIM.