Study of the intracluster and intergalactic medium in the Sculptor supercluster with Suzaku

We studied the high-temperature plasma in the direction of the Sculptor supercluster at z = 0.108 with Suzaku. Suzaku carried out four observations in the supercluster: namely, A 2811, A 2811 offset, A 2804, A 2801 regions in 2005 November-December, including the regions beyond the virial radii of these clusters. The spectra taken in regions outside of the virial radii of the member clusters were used as background that included both of the Galactic and Cosmic X-ray Background (CXB) components. Temperature and metal abundance profiles were determined to the virial radii of the member clusters, and we then searched for oxygen line emission in the region outside of the virial radii of the clusters. As a result, the temperature of the clusters decreased toward the virial radii, and the spectral fits for the filament region did not require any extra component other than the Galactic and CXB components. We constrained the intensities of the O VII and O VIII lines to be less than 8.1 and 5.1 × 10^-8 photons cm^-2 s^-1 arcmin^-2, respectively, as 2 σ upper limits in the filament region. The intensity of O VII indicates n_H < 1.6 × 10^-5 cm^-3 (Z=0.1Z⊙)^-1/2(L=25 Mpc)^-1/2, which corresponds to an over density of δ < 60(Z=0.1Z⊙)^-1/2(L/25 Mpc) ^-1/2.