Earliest Galaxies in the Universe Were Much Brighter Than Astronomers Considered


The earliest galaxies in the Universe, which formed approximately one billion years after the Big Bang, were significantly much brighter than researchers expected, new information from NASA’s space telescopes Hubble and Spitzer discovered in a couple of particular wavelengths of infrared light.

Even if the first stars’ birth period is unknown, some clues imply that the process started about 100 and 200 million years after the Big Bang, when the Universe abounded of neutral hydrogen gas. The gas is thought to have merged into stars which later formed the first galaxies, and after approximately one billion years after the big blast, the Universe turned into a bright welkin. Also, electrons of the all-over-present neutral hydrogen gas have been reduced in what is called the process of ionization.

Extended-wavelength shapes of light, for example, radio waves and visible light, moved across the Universe before the Universe’s massive change, but the shorter wavelengths of light such as X-rays, gamma rays and ultraviolet light, were briefly stopped by the neutral hydrogen particles. These conflicts would unclothe the neutral hydrogen molecules of their electrons, thus the process of ionization.

However, this process seems unlikely to have generated sufficient ionizing radiation to impact all the hydrogen present in the Universe. Therefore questions regarding the actual culprit (perhaps individual stars, or massive galaxies) were asked.

Earliest Galaxies in the Universe Are Much Brighter Than Astronomers Considered

But if these were the doer, the young cosmic pioneers would have been distinct from the majority of today’s stars and galaxies, which generally don’t discharge massive quantities of ionizing radiation. Again, perhaps another type of objects birthed the event, such as supernovas. NASA’s Spitzer Space Telescope gathered some insights of the period before the Epoch of Reionization by observing two particular areas of the sky for more than 200 hours separately and collecting the light that traveled for approximately 13 billion years until it got to us.

Data from NASA/ESA Hubble and Spitzer Space Telescope, Stephanie De Barros from the University of Geneva and her fellow associates observed and analyzed 135 far-away galaxies, and discovered that these places were all specifically bright in two particular wavelengths or infrared light generated by ionizing radiation coming into collision with hydrogen and oxygen.

This suggests that the galaxies were controlled by the first, enormous stars mainly structured of helium and hydrogen, having tiny quantities of heavy metals (nitrogen, oxygen, carbon), in comparison to heavenly bodies found in current galaxies. The Epoch of Reionization hasn’t suddenly occurred, it was more like a process-event, so even if the outcomes are not sufficient to conclude the cause of this cosmic occurrence, they give new details regarding the way the Universe developed until now, and how the transformation happened.

Dr. Pascal Oesch, from the University of Geneva, and colleague to Dr. Stephanie de Barros said that these observations of Spitzer and conclusions reached are taking the astronomers and researchers a step closer to gathering all the puzzles on the enigma of cosmic reionization. The study and its results were published in the journal Monthly Notices of the Royal Astronomical Society.


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