First-ever direct image of the cosmic web reveals the Universe’s hidden highways

Scientists have produced the clearest view ever of part of the cosmic web, the enormous hidden network of matter that stretches across the Universe and connects galaxies together. After spending hundreds of hours collecting observations, an international team captured a detailed image of a massive cosmic filament linking two actively forming galaxies from a time when the Universe was only about 2 billion years old. The discovery offers a rare direct look at one of the largest structures in exist

Modern cosmology suggests that dark matter makes up roughly 85% of all matter in the Universe. Although invisible, dark matter is believed to shape a gigantic web-like framework made of long filaments. At the points where these filaments intersect, galaxies form and shine brightly. Scientists think these filaments also act as intergalactic highways, channeling gas into galaxies and fueling the birth of new stars. Learning how this gas moves through the cosmic web is considered essential for understanding how galaxies develop. But detecting that gas has been extremely difficult. Most intergalactic gas has only been observed indirectly by measuring how it absorbs light from bright objects behind it. Hydrogen, the most abundant element in the cosmos, emits only a very faint glow, making direct observations nearly impossible for older instruments. The new observations were carried out by researchers from the University of Milano-Bicocca together with scientists from the Max Planck Institute for Astrophysics (MPA). The team used MUSE (Multi-Unit Spectroscopic Explorer), a powerful instrument mounted on the European Southern Observatory's Very Large Telescope in Chile. Even with such advanced technology, the project required one of the most ambitious MUSE observing campaigns ever conducted in a single region of the sky. Researchers gathered data over hundreds of hours to detect the faint filament clearly enough for detailed analysis.

Key points

• Modern cosmology suggests that dark matter makes up roughly 85% of all matter in the Universe.
• Although invisible, dark matter is believed to shape a gigantic web-like framework made of long filaments.
• At the points where these filaments intersect, galaxies form and shine brightly.
• Scientists think these filaments also act as intergalactic highways, channeling gas into galaxies and fueling the birth of new stars.
• Learning how this gas moves through the cosmic web is considered essential for understanding how galaxies develop.