Rare glimpse at massive outstretched gas cloud could reveal universe’s hidden structure
Anatoly Klypin/New Mexico State University, Joel Primack/UC Santa Cruz
All of the universe’s matter, cosmologists believe, forms a web of dark matter and gas that was spun shortly after the Big Bang and has been stretching out ever since. Now astronomers say they have glimpsed a brightly lit strand of this web.
But the researchers found far more cold gas than they expected based on computer simulations of the cosmic web, suggesting the web’s structure could differ from theoretical predictions.
Most of the universe’s mass seems to reside in slender interconnected filaments, which are primarily made of dark matter with smaller amounts of gas. Cosmologists’ theories suggest that gas collects at filament intersections and becomes dense enough to form luminous galaxies. But because the filaments’ dark matter is invisible and their sparse gas emits little light, the threads connecting galaxies have remained mostly hidden.
Astronomers have recently begun to spot filaments backlit from a distance by extremely