Since ancient times, philosophers and scholars have considered the beginning of time and have also tried to determine when all things began. It has only been in the era of modern astronomy that we have come close to answering this question.
According to the most widely accepted cosmological model, the universe began around 13.8 billion years ago with Bang Bang.
Nevertheless, astronomers are still unsure of what the early universe looked like as this period coincided with the cosmic “Dark Age”. Therefore, astronomers keep looking at the range of their instruments to see when galaxies first formed.
Thanks to new research from an international team of astronomers, the oldest and farthest galaxy ever seen in our universe has been identified (GN-z11).
The team, whose research was recently published in the journal Nature astronomy, Was led by Linhua Jiang of Kevali Institute for Astronomy and Astrophysics and Prof. Nobuneri Kashikawa of the University of Tokyo.
He was joined by researchers from the Observatories at the Carnegie Institution for Science, Steward Observatory, Geneva Observatory, Peking University and the University of Tokyo.
Simply put, Cosmic Dark Ages began about 370 thousand years after the Big Bang and continued for the next 1 billion years.
At this time, the only light sources were either previously released photons – which are still detectable today as cosmic microwave backgrounds (CMBs) – and those released by neutral hydrogen atoms. Due to the expansion of the universe, the light of these photons has moved so much that they are invisible to us today.
This effect is known as “redshift”, where the wavelength of light increases (or “shifts” toward the red end of the spectrum) as it passes through the ever-expanding universe on its way to reach us.
For objects moving closer to our galaxy, the effect is reversed, shortening the wavelength and moving toward the blue end of the spectrum (aka “blueshift”).
For nearly a century, astronomers have used these effects to determine the distance of galaxies and the rate at which the universe is expanding. In this case, the research team used the KK I telescope in Maunaka, Hawaii to measure the redistribution of the GN-z11 to determine its distance.
The results they obtained indicate that it is the farthest (and oldest) galaxy ever found. As Kashikawa stated in a press release from the University of Tokyo:
“From previous studies, the galaxy GN-z11 appears to us to be the farthest detectable galaxy by 13.4 billion light years or 134 nonillion kilometers (which is followed by 30 zeros). But measuring and verifying such distances Not easy. Work. “
Specifically, the team investigated carbon emission lines coming from the GN-Z11, which were in the ultraviolet range when they left the galaxy and were moved by a factor of 10 – infrared (0.2 micrometers) – until It reached the earth.
This level of redshift indicates that this galaxy was observed around 13.4 billion years ago – aka exactly 400 years after the Big Bang.
At this distance, the GN-z11 is so far that it defines the limits of the self-observable universe! While this galaxy was observed in the past (by Hubble), it took the Keck Observatory’s resolving power and spectroscopic capabilities to make accurate measurements.
This was demonstrated as part of the Multi-Object Spectrograph for the Infrared Exploration (MOSFIRE) survey, which captured the emission lines from GN-Z11 in detail.
This allowed the team to estimate distances for this galaxy, which was improved by a factor of more than 100 from any measurements made earlier. Where is Kashikawa:
“The Hubble Space Telescope detected signatures in the GN-z11 spectrum several times. However, even Hubble cannot resolve ultraviolet emission lines to the degree we require. So we can have a more up-to-date Turned into ground-based inquiry. ” A device for measuring emission lines, called MOSFIRE, mounted on the Keek I telescope in Hawaii. “
If subsequent observations can confirm the results of this latest study, astronomers can say with certainty that GN-z11 is the farthest galaxy ever discovered. Through the study of such objects, astronomers hope to be able to shed light on a period of cosmic history, when the universe was only a few hundred million years old.
This period coincided with the Universe beginning to emerge from the “Dark Eggs”, when the first stars and galaxies formed and filled the early Universe with visible light.
By studying these, astronomers hope to learn more about how the large-scale structures of the universe evolved later. It will be assisted by next generation telescopes – like the James Webb Space Telescope (JWST) – scheduled to launch on October 31, 2021.
These instruments will allow astronomers to be able to study the “Dark Age”, a time when the only non-CMB light was a spin line of neutral hydrogen – at far microwave wavelengths (21 cm).
To be able to investigate the very beginning of the universe and see it as the first stars and galaxies. What an exciting time!
The observations that made this research possible were conducted under the Time Exchange Program between the KK Observatory and Subaru Telescope on Mounaka, Hawaii.
This article was originally published by Universe Today. Read the original article.