摘要：We report the first statistical detection of X-ray emission from cosmic web filaments in ROSAT data. We selected 15 165 filaments at 0.2 < z < 0.6 ranging from 30 Mpc to 100 Mpc in length, identified in the Sloan Digital Sky Survey survey. We stacked the X-ray count-rate maps from ROSAT around the filaments, excluding resolved galaxy groups and clusters above the mass of ∼3 × 1013 M⊙as well as the detected X-ray point sources from the ROSAT,Chandra, andXMM-Newtonobservations. The stacked signal results in the detection of the X-ray emission from the cosmic filaments at a significance of 4.2σin the energy band of 0.56−1.21 keV. The signal is interpreted, assuming the Astrophysical Plasma Emission Code model, as an emission from the hot gas in the filament-core regions with an average gas temperature of 0.9−0.6+1.0keV and a gas overdensity ofδ ∼ 30 at the center of the filaments. Furthermore, we show that stacking the SRG/eROSITA data for ∼2000 filaments only would lead to a ≳5σdetection of their X-ray signal, even with an average gas temperature as low as ∼0.3 keV.
关键词：encosmology: observationslarge-scale structure of Universediffuse radiationX-rays: diffuse background
