A new study challenges the long-held belief that the universe contains several hundred billion galaxies. Recently published in the Astrophysical Journal Letters, the theory reveals a universe with far fewer galaxies than previously thought. Using specially-developed computer simulations, a team of researchers has estimated the number of faint, distant galaxies as 10 to 100 times less than earlier claims.
Since its launch in 1990, the Hubble Space Telescope has allowed scientists and astronomers to uncover some of the most startling mysteries of outer space. Unlike the brighter galaxies present in the observable part of the universe, the faint galaxies exist in a distant region, which even the Hubble struggles to see. Formed over ten billion years ago, the faint galaxies were, until now, thought to be hundreds or thousands of times more in number than the bright galaxies. According to the new study, however, the number is merely ten to hundred times greater.
The study is part of a project, carried out jointly by the University of California, San Diego, Michigan State University and the Georgia Institute of Technology. For the research, the team relied on National Science Foundation’s advanced Blue Water supercomputer, to generate incredibly precise simulations of thousands of distant galaxies as well as their interactions through radiation and gravity. Using the results, the scientists were able to investigate, in great detail, the process of formation of star systems in early universe. Speaking about the project, Brian O’Shea, a professor of physics and astronomy at Michigan State University, said:
Our work suggests that there are far fewer faint galaxies than we once previously thought. Earlier estimates placed the number of faint galaxies in the early universe to be hundreds or thousands of times larger than the few bright galaxies that we can actually see with the Hubble Space Telescope. We now think that number could be closer to ten times larger.
According to O’Shea, the simulations correctly mapped the distant, observable galaxies that have already been discovered and listed. However, in the case of faint galaxies, the estimates were found to be inconsistent with former claims. Instead of an astronomically large number of faint star clusters, the simulations reported a far emptier picture of the universe. The team is currently awaiting the launch of the more advanced James Webb Space telescope, that will be operational from the year, 2018. A rightful successor to the Hubble, the JWST’s improved technology will allow the researchers to confirm their findings. O’Shea said:
A deeper understanding based on theory may be necessary to correctly interpret what’s being seen, such as high redshift survey results.
Michael Norman, the director of UCSD’s San Diego Supercomputer Center, believes that the Hubble Space Telescope can see only “the tip of the iceberg” that makes up the innumerable faint galaxies yet to be discovered.
Source: Astrophysical Journal Letters