Image: TOM THEUNS/Max Planck Institute for Astrophysics
Using the European Southern Observatory's Very Large Telescope, researchers have spotted a strand of the early universe. The new findings, which will appear in the journal Astronomy and Astrophysics, lend support to computer-simulation-based reconstructions of the young universe as a cosmic spider web (right).
When Palle Mller of the ESO and colleagues calculated the distances to the extremely distant galaxies captured by the VLT and plotted them on a three-dimensional map, they found that the galaxies occupy an invisible thread. The results match predictions made by current theories of the early development of the universe. "We have little doubt that for the first time, we are here seeing a small cosmic filament in the early universe," Mller reports. "At this enormous distance and correspondingly long look-back time, we see it at a time when the universe was only about two billion years old. This is obviously in agreement with the predictions by the computer models of a web-like structure."
The first galaxy building blocks, according to these models, formed inside the strands of the web and, over time, streamed along the threads toward the nodes. When they met at these cosmic intersections, the star-forming regions merged and eventually formed the galaxy clusters we know today. Thus, the structure of the universe changed from being dominated by filaments to housing large clusters of galaxies connected by remnants of these filaments.
Down the road, the researchers hope to make more detailed comparisons between observations and predictions. In particular, they are searching for clumps of hydrogen that will point them to objects forming inside the filamentsso-called LEGO blocks of cosmology. "We have shown that we now have an observational method with which we may study the cosmic web in the early universe, and the VLT is a great tool for such studies," the team notes. "The way forward now is pretty clearwe just have to find those faint and distant LEGOs and then do the spectral observations from which we may determine how they are distributed in space."