Scientists Capture First-Ever Photograph Of The ‘Cosmic Web’ Connecting Us To Other Galaxies
Scientists have long hypothesized that there is a network of invisible gas filaments bridging light-years across the universe, connecting everything in a kind of cosmic web. Now scientists believe they have the first picture of this network. Their findings were just published in the journal Science.
It is theorized that this cosmic web formed in the aftermath of the Big Bang: according to Space.com, hydrogen gas collapsed into "sheets," which then splintered into these filaments. Where two filaments intersect, galaxies are born. Researchers had seen glimpses of this galactic network in the past, but never to such a degree as we see now.
How did they do it? Scientists used the ESO'S MUSE instrument coupled with the Very Large Telescope in Chile to target a galaxy protocluster in the constellation Aquarius 12 billion light-years away. A protocluster is like a nebula for galaxies: where they are born and, as far as we know, they are the largest structures in the universe.
Rather than use traditional imaging, scientists chose instead to scan for hydrogen gas reacting to ultraviolet wavelengths given off by the galaxies in this protocluster. In other words, they looked for the filaments in the galaxies' light.
What they discovered was indeed a web connecting these galaxies, its thin strands stretching over 3 million light-years.
Astronomer and lead study author Hideki Umehata said, "These gaseous structures were predicted for years theoretically, but astronomers have struggled to map them directly…Our work shows that mapping cosmic web filaments is now possible, which means that we have obtained a novel tool to understand the formation of galaxies and supermassive black holes."