- The simulations were led by Michigan State University
- The distant universe was expected to be abundant in faint galaxies
- But simulations showed they are ten to 100 times less in number
- Could be confirmed by the upcoming James Webb Space Telescope
The universe may have 10 to 100 fewer galaxies than thought, according to a study. Simulations have showed that so-called faint galaxies, predicted to be abundant in the distant universe, are actually much less prevalent. And future telescopes such as the James Webb Space Telescope could be used to confirm whether the simulations are correct. The findings were made by scientists at Michigan State University, the Georgia Institute of Technology and the University of California, San Diego. Specifically, they were looking at some of the most distant galaxies in the universe, which telescopes like the Hubble Space Telescope struggle to see. They used results from a project called the Renaissance Simulations, which involves extremely accurate calculations of the formation of distant galaxies.
‘Our work suggests that there are far fewer faint galaxies than one could previously infer,’ said lead author Dr Brian O’Shea from Michigan State University. Dr Michael Norman from the University of California, one of the authors on the study, said that Hubble could only see ‘the tip of the iceberg’ when it comes to studying distant galaxies. Using its observations, scientists had come up with estimates for how many more they expected to find. ‘A key question is how many galaxies are too faint to see,’ said Dr Norman. And analysing the new ultra-detailed simulations found there were ‘ten to 100 times fewer galaxies than a simple extrapolation would predict.’
Distant, faint galaxies were formed more than ten billion years ago when the universe was extremely young, but they are difficult to find and study. Earlier predictions had suggests that the number of faint galaxies were hundreds or thousands of times greater than the bright galaxies that telescopes like Hubble can see. The new figure suggests the number is just 10 times greater, though. To make the findings, thousands of galaxies and their interactions via gravity and radiation were simulated at the US National Science Foundation’s Blue Water supercomputer. It is hoped that the James Webb Space Telescope, due to launch in 2018, will be able to peer deep into the universe and confirm the findings. The study was published in the journal Astrophysical Journal Letters.