Tiny galaxies may reveal how the universe heats up
(Mirror Daily, United States) – We have an idea about how the universe was formed but we want to know what happened after that and a tiny green pea galaxy reveals post Big-Bang theory.
According to scientists, several hundred thousand years after the creation of universe, everything was still very hot and very dense that matter couldn’t be neutral, but ionized instead. After almost 400, 000 years later, the universe has finally started to cool off, which allowed the matter to stop ionizing and become neutral which led to the formation of the first structures in the universe. Most of them were simple gas clouds made of hydrogen and helium.
These clouds later formed stars and galaxies due to gravity. After approximately one billion years after the universe was formed, hydrogen started re-ionizing, which meant the universe reheated. It was thought, but not proven, that galaxies were responsible for this heating. Recently, an international team of astronomers has pinpointed again towards this theory, this time proving it real.
The astronomers come from the U.S., Germany, France, Ukraine and the Czech Republic. They used the ultraviolet spectrometer from the Hubble Space Telescope and discovered a dwarf galaxy which emits ionizing photons into the space between galaxies. According to the team, these photons are the ones responsible for the re-ionization of the Universe.
Green peas are newly discovered galaxies which are small and round and emit green light. The ionizing photons are ejected through stellar explosions or very strong winds. However, so far, scientists weren’t able to find a galaxy that ejects enough ionizing photons to support their theory.
The newly discovered galaxy, the J0925+1403 is located at three billion light years from Earth and has an 8 percent ejection which could indeed explain how the universe heated through cosmic re-ionization.
Of course, only one galaxy ejecting photons might not be enough to prove that this is the way the universe heated. However, researchers are still looking into the problem and it is expected that they will have more answers after 2018, when the James Webb Space Telescope will be launched. This new telescope is the successor of the Hubble and it is hoped that it will revolutionize the way astronomers observe the universe.
Image source: www.bing.com
Joe Hennessey
