X-Ray Absorption By WHIM in the Sculptor Wall
  We present XMM RGS and Chandra LETG observations of the blazar, H 2356-309,
located behind the Sculptor Wall, a large-scale galaxy structure expected to
harbor high-density Warm-Hot Intergalactic Medium (WHIM). Our simultaneous
analysis of the RGS and LETG spectra yields a 3-sigma detection of the crucial
redshifted O vii K-alpha line with a column density (>~ 10^{16} cm^{-2})
consistent with similar large-scale structures produced in cosmological
simulations. This represents the first detection of non-local WHIM from X-ray
absorption studies where XMM and Chandra data are analyzed simultaneously and
the absorber redshift is already known, thus providing robust evidence for the
expected repository of the "missing baryons".
