Home Top

Is the universe EMPTIER than we thought? Simulations suggest there could be 100 times fewer galaxies than predicted

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

Published: 07:17 EST, 3 July 2015 | Updated: 08:28 EST, 3 July 2015

View
comments

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 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. Shown is Hubble's famous Ultra-Deep Field image

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.

WHAT IS THE JWST?

The James Webb Space Telescope (JWST) will be a large infrared telescope with a 6.5-meter (21ft) primary mirror.

The project is working to a 2018 launch date.

The JWST will be the premier observatory of the next decade, serving thousands of astronomers worldwide.

It will study every phase in the history of our universe, ranging from the first luminous glows after the Big Bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own solar system.

‘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.’

The James Webb Space Telescope (JWST), artist's impression shown, will be a large infrared telescope with a 6.5-meter (21ft) primary mirror. The project is working to a 2018 launch date. It will be used to peer into the distant universe and verify theories such as this

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.

Shown here is EGS-zs8-1, recently found to be the most distant galaxy in the universe. Measured at 13.1 billion light-years away, the discovery offers a rare opportunity to see how galaxies began to take shape when the cosmos was still extremely young