Tracing the warm–hot intergalactic medium in the local Universe

We present a simple method for tracing the spatial distribution and predicting the physical properties of the Warm–Hot Intergalactic Medium (WHIM), from the map of galaxy light in the Local Universe. Under the assumption that biasing is local and monotonic we map the  ∼2 h ⁻¹ Mpc  smoothed density field of galaxy light into the mass-density field, from which we infer the spatial distribution of the WHIM in the Local Supercluster. Taking into account the scatter in the WHIM density–temperature and density–metallicity relation, extracted from the z = 0 outputs of high-resolution and large-box-size hydrodynamical cosmological simulations, we are able to quantify the probability of detecting WHIM signatures in the form of absorption features in the X-ray spectra, along arbitrary directions in the sky. To illustrate the usefulness of this semi-analytical method we focus on the WHIM properties in the Virgo cluster region.