The early universe is much more different than how it is today. As it formed, many that were present then are no longer seen now or else have lesser numbers. A large number of dwarf galaxies were present in the early universe, though now they have become rare.
Many of the dwarf galaxies that could still be found are in distant places in the universe. Scientists have theorized that the farther from the Earth an object is, the farther it goes back in time. Dwarf galaxies reside far into the universe that astronomers see them to likely hold some of the answers as to how the universe was formed.
Researchers from the University of California Riverside found the large number of dwarf galaxies in the distant parts of the universe. These galaxies are some of the smallest and dimmest, yet they hold the key to how the universe was back then. These galaxies are thought to have a role in the reionization of the universe. That means making the universe a place that has much light from a time when there was mostly darkness.
Dwarf galaxies aren't easy to study as they are faint and distant. They are also elusive, since there aren't that many as they were at the time the universe formed. Many of the best telescopes today still have a hard time looking for them, according to the University of California Riverside's site.
To view these distant objects, another object would have to be used. The object would have to be in the line of sight of the distant object, making it as sort of a lens. Through this object it magnifies the light coming from the distant object. This method has been called gravitational lensing.
A group of galaxies have been targeted for the study. The study's lead author Anahita Alavi, a postdoctoral scholar for the Department of Physics and Astronomy at the University of California Riverside. Working with the study is Brian Siana, assistant professor for the Department of Physics and Astronomy.
For the study the team used the Wide Field Camera 3 of the Hubble Space Telescope in order to study a cluster of galaxies, as Phys Org reports. For data analysis the team used the spectroscopic data from the Multi-Object Spectrograph for Infrared Exploration (MOSFIRE) on the W.M. Keck Observatory. The study has found that there have been more dwarf galaxies in the past than they are today.
Plans for further observations of dwarf galaxies are being made with the use of new telescopes such as the James Webb Space Telescope which would be launched in 2018. The study has shown that a large number of dwarf galaxies have been present in the early universe, and that they have contributed much to its formation. Astronomers are also studying bright radio bursts that are still a mystery today.