Constrained Simulations of the Real Universe: II. Observational Signatures of Intergalactic Gas in the Local Supercluster Region

Abstract

We present results of gasdynamics+N-body constrained cosmological simulations of the Local Supercluster region (LSC; about 30/h Mpc around the Virgo cluster), which closely mimic the real Universe within 100 Mpc by imposing constraints from Mark III catalog of galaxy peculiar velocities. The simulations are used to study the properties and possible observational signatures of intergalactic medium in the LSC region. We find that, in agreement with previous unconstrained simulations, about 30% of the gas in this region is in the warm/hot phase at T~10^5-10^7 K, and about 40% in the diffuse phase at T<10^5 K in low-density regions. The best prospects for detection of the warm/hot intergalactic medium of the LSC located in filaments and in the vicinity of virialized regions of groups and clusters are through absorption in resonant lines of OVII and OVIII in soft X-rays and in the OVI doublet in UV. If intergalactic gas in filaments (rho/<rho>~ 1-10) is enriched to typical metallicities of >0.05, the column densities of OVI, OVII, and OVIII along a random line of sight near the North Galactic Pole, especially near the supergalactic plane, have a significant probability to be in the range detectable by the current (FUSE,XMM) and future (Constellation-X) instruments. (Abridged)