From time to time, philosophers and scholars have thought about the beginning of time and even tried to find out when it all began. It is only in the age of modern astronomy that we came close to answering that question with a degree of certainty.
According to the widely accepted cosmological models, the Universe began with the Bang Bang about 13.8 billion years ago.
Nevertheless, astronomers are still uncertain about what the early Universe looked like from this time at the same time as the cosmic “Dark Ages”. So astronauts push the boundaries of their instruments to see when the earliest galaxies formed.
Thanks to new research by an international team of astronauts, the oldest and most distant galaxy has ever been seen in our Universe to date (GN-z11).
The team, whose research was recently published in the journal Astronomy of nature, led by Linhua Jiang of the Kavli Institute for Astronomy and Astronomy and Professor Nobunari Kashikawa of the University of Tokyo.
They were joined by researchers from the Carnegie Institute for Science Observatory, the Steward Observatory, the Geneva Observatory, Peking University, and the University of Tokyo.
Simply put, the Cosmic Dark Ages began around 370 thousand years after the Great Bang and continued for another 1 billion years.
At this time, the only light sources were both the previously released photons – which are still to be found today as a Cosmic Microwave (CMB) background – and those they were released by neutral hydrogen atoms. The light of these photons has been moved so much by the expansion of the Universe that they are invisible to us today.
This effect is called a “redshift,” where a wave of light travels far (or “moves” towards the red end of the spectrum) as it passes through the ever-expanding cosmos. way to reach us.
For objects moving closer to our galaxy, the effect is reversed, with the wave shortening and moving toward the blue end of the spectrum (aka. “Blueshift” ).
For nearly a century, astronomers have used these effects to determine the speed of galaxies and the extent to which the Universe is expanding. In this case, the research team used the Keck I telescope at Maunakea, Hawaii, to measure GN-z11 refraction to determine its speed.
The results they found showed that it is the longest (and oldest) galaxy ever seen. As Kashikawa explained in a press release from the University of Tokyo:
“From previous studies, the galaxy GN-z11 appears to be the furthest galaxy from us, at 13.4 billion light-years, or 134 nonillion kilometers (that’s 134 followed by 30 zeros). But it’s not easy to measure and to test that speed. action. “
In particular, the team examined the carbon emission lines emanating from GN-z11, which were in the ultraviolet range when they left the galaxy and were moved by a factor of 10 – to the infrared (0.2 micrometers) – before reaching the Earth.
This level of regression indicates that this galaxy existed as it was seen about 13.4 billion years ago – aka just 400 million years after the Big Bang.
At this rate, GN-z11 is so far that it defines the true end of the visible World! Although this galaxy has been observed in the past (by Hubble), it used the Keck Observatory’s resolution power and spectroscopic capabilities to make accurate measurements.
This was done as part of the Multi-Object Spectrograph for In-Infrared Screening (MOSFIRE) study, which accurately captured the transmission lines from GN-z11.
This allowed the team to make distance estimates for this galaxy developed by a factor of 100 over any previous measurement. Kashikawa said:
“The Hubble Space Telescope found its signature many times in the GN-z11 spectrum. However, even the Hubble can’t solve ultraviolet emission lines to the level we needed. So we turned to a newer spectrum based on ground, a device for measuring transmission lines, called MOSFIRE, which is mounted to the Keck I telescope in Hawaii. “
If subsequent studies can confirm the results of this latest study, astronomers can say with certainty that GN-z11 is the longest galaxy ever seen. By studying objects like this one, astronauts hope to be able to shed light on a time of cosmic history when the Universe was only a few hundred million years old.
This period coincided with the beginning of the Universe’s emergence from the “Dark Ages”, when the first stars and galaxies of the early Universe were created and filled with visible light.
By studying these, astronomers hope to learn more about how the great structures of the Earth came into being. This will be aided by next generation telescopes such as the James Webb Space Telescope (JWST) – launched on October 31, 2021.
These instruments even allow astronauts to study the “Dark Ages” themselves, a time when the only non-CMB light was not a spinning line of neutral hydrogen – in the long microwave wavelength (21 cm).
To be able to explore the very beginning of the Universe itself and see how the first stars and galaxies perform. What an exciting time it will be!
The observations made by this research were made under the time exchange program between the Keck Observatory and the Subaru Telescope on Maunakea, Hawaii.
This article was originally published by Universe Today. Read the original article.