Looking at the universe through a telescope means looking back in time, as the speed of light is so slow that even the light of nearby stars in our own galaxy takes years or millennia to reach us. As such, even the most distant galaxies give man a glimpse into the past of the universe – this is what the discovery of the farthest galaxy was found to be the most ancient.
According to a new study Published December 14th In the journal Nature Astronomy, astronomers have confirmed the most distant galaxies in our universe. The GN-Z11 galaxy is so far away that it is thought to form the boundary of the universe at a distance of 13.4 billion light years or 134 billion kilometers from the Earth, which means that the light we saw left 13.4 billion years ago – Just 400 million years after the Big Bang.
Nobnery Kashikawa, co-author of the study at the University of Tokyo’s School of Science fiction, explained to the salon that the designation as the “oldest” galaxy for GN-Z11 could be short-lived, as the telescope constantly scans the sky.
“GN-Z11 is the farthest galaxy we know today, and maybe tomorrow we will find more distant galaxies,” Kashikawa wrote via email.
Although the distant galaxy was originally observed by the Hubble Space Telescope in 2016, Kashikawa and his team used the Cake 1 Telescope in Hawaii to confirm its age and distance. At the time of its discovery, astronomers estimated that it was 13.4 billion light-years away, based on a discovery of what appears to be a “characteristic break” in distant galaxies.
Trying to find such a distant, obscure galaxy pushed the Hubble Space Telescope to its technical limitations.
“Our spectroscopic observations suggest that the galaxy is even farther away than we originally thought, just beyond the distance Hubble could observe,” said Garabial Brammer, author of the 2016 study, in one. Statement.
Astronomers measure the galaxy’s distance by determining its redshift, which is a measure of how fast it is moving from Earth. As the universe expands, every object in the sky that is not bound by gravity to our own galaxy is revolving around the earth; As they do so, these ‘objects’ The light lasts longer and therefore the redder wavelength. The farther away the galaxy is, the higher the redshift.
To determine how far GN-Z11 is from Earth, Kashikawa’s team studied its spectral characteristics, as the observations made by the Hubble Space Telescope were limited.
“Even Hubble can’t solve the ultraviolet emission lines to our required degree,” Kashikawa said. Said in Statement. “So we turn to a more advanced ground-based spectrograph, a device for measuring emission lines, called a MOSfire, mounted in Cake I telescope in Hawaii“
Kashikawa told the salon that it was “difficult” to determine if there was really a break in the spectrum. In particular, the team turned to ultraviolet light to detect redshift chemical signatures. What he boiled had the right devices to confirm and identify the spectral brake.
“Its wavelength cannot be measured accurately, so the accuracy of determining the distance from the galaxy was uncertain,” Kashikawa told Salon by email. “Once we assume that the carbon and oxygen emission lights we have detected at this time are real, it is not so difficult to calculate the next distance.”
Although this galaxy is far away, astronomers are hopeful that it contains information that we can learn about our own galaxy and the universe.
“The detected light of carbon and oxygen indicates a special kind of physical condition that is not found in existing galaxies,” Kashikawa told the salon. “GN-Z11 is thought to be only 70 million years old and an estimated billion times larger than the Sun (a component of the stars) suggests that this young galaxy was born and evolved rapidly.”
Kashikawa added: “The fact that carbon and oxygen were found in GN-Z11 shows that this galaxy is not the first (metal-free) galaxy in the universe.” Since heavier elements than hydrogen and helium are only formed in larger stars, the presence of heavier elements such as carbon indicates that the stars in the galaxy are at least second generation, meaning that one major generation of the larger Sun is already alive and dead, expelling their metals. . In the galaxy.
This means, Kashikawa said, that the universe’s first galaxies are still “in a more distant universe unknown to mankind.”
Next year will be a big year for astronomy, especially in terms of how we better understand the universe.
“The space boundary is likely to expand dramatically,” Kashikawa said.
And that’s partly because the James Webb Space Telescope will be launched from French Guiana on October 31, 2021, and will carry on the legacy of the Hubble Telescope. In particular, it will observe the infrared universe and find light from distant, old galaxies. Infrared light cannot be detected well from Earth due to atmospheric interference, and so a space-based telescope is needed to examine the universe in infrared.
“The [James Webb Space Telescope] Eric Smith, a program scientist at NASA Web, headquartered at the agency, said the observatory would detect the light of the first pay-generation of galaxies formed in the early universe after a large diagonal and study the atmosphere of a nearby exoplanet. Statement earlier.
