Astronomers have begun to resolve the structure of the universe on a level of detail previously only seen in simulations. Thanks to observations of bright quasars, we’ve been able to trace out the vaguest outline of the cosmological structure of the universe for some time, but these bright systems are rare and don’t really show any detail on what is going on. 

Now, using 140 hours of observing time on the 8.2m Very Large Telescope (VLT) in Chile, astronomers have peered into the faint details of the large-scale structure and resolved a sea of previously undiscovered small galaxies. According to study co-author Joop Schaye: We think that the light we are seeing comes mainly from young galaxies, each containing millions of times fewer stars than our own Milky Way. Such tiny galaxies were likely responsible for the end of the cosmic ‘dark ages’, when less than a billion years after the Big Bang, the universe was illuminated and heated by the first generations of stars. 

So far, only a tiny fragment of the sky has been seen, but the researchers behind this work are working to improve the camera they’re using on the VLT so that it can capture two to four times more of the sky in its field of view. This work is being published in Astronomy and Astrophysics and was led by Roland Bacon.

Looking into the first moments of the universe isn’t easy, and sometimes it takes more than just a massive telescope and countless hours of observing. Sometimes, you have to actually figure out how to use gravity as a lens to peer into the early universe. 

More Information

NOVA press release

CNRS press release

“The MUSE Extremely Deep Field: the Cosmic Web in Emission at High Redshift,” Roland Bacon et al., to be published in Astronomy & Astrophysics (preprint on arxiv.org)