Overview

• The 23-million-light-year filament links galaxy clusters A3532, A3530, A3528-N and A3528-S and contains hot gas at temperatures above 10 million °C with about ten times the mass of the Milky Way.
• Researchers combined JAXA’s Suzaku and ESA’s XMM-Newton observations to isolate the filament’s faint X-ray glow by modeling and removing contaminating sources such as active galactic nuclei.
• Spectroscopic analysis determined a particle density of roughly ten per cubic meter—30–40 times the universe’s average—consistent with expectations for the warm-hot intergalactic medium.
• The filament’s measured properties align closely with predictions from cosmological standard-model simulations, supporting the idea that missing baryonic matter resides in such structures.
• The refined method for filtering X-ray background paves the way for future searches and characterizations of similar filaments to further account for the universe’s unobserved ordinary matter.