Scientists have produced an extraordinarily detailed direct view of part of the cosmic web — the enormous network of matter connecting galaxies across the Universe.
The observed filament stretches roughly 3 million light-years and links two distant galaxies whose light has travelled for nearly 12 billion years to reach us. Astronomers detected the extremely faint glow of hydrogen gas filling the space between them.
The cosmic web is the largest known structure in nature. Galaxies and galaxy clusters are concentrated along enormous filaments surrounding vast, comparatively empty regions called cosmic voids.
Most of the web’s mass is thought to be dark matter. Its gravity provides the underlying framework, while ordinary gas flows along these filaments and supplies galaxies with material for forming new stars.
Astronomers have mapped the cosmic web indirectly for decades by measuring galaxies, gravitational lensing and absorption in the light of distant quasars. Directly detecting the faint gas between galaxies is far more difficult because its glow is incredibly weak.
Using ESO’s Very Large Telescope and its MUSE instrument, researchers accumulated more than 140 hours of observations to reveal this filament in unprecedented detail.
One important clarification bitch: images showing the entire Universe as a dense web of countless filaments are generally simulations or reconstructed maps. The direct observation captures a specific filament — not a photograph of the entire cosmic web at once.
Source: Nature Astronomy; ESO; Max Planck Institute for Astrophysics