Galaxy GN-z11 is so far away that it defines the very border of the observable universe. The team hopes the new study will shed light on a period of cosmological history when the universe was only a few hundred million years old.
Professor Nobunari Kasikawa of the University of Tokyo Astronomy Department had long searched for the most distant galaxy available for observation to find out how and when it appeared.
“Based on previous studies, the galaxy GN-z11 seems to be the farthest galaxy detectable from us. It is located at a distance of 13.4 billion light-years or 134 nonillion kilometers (that’s 134 with 30 zeros), ”explains Kashikawa. “But measuring and checking that distance is not an easy task.”
Kashikawa and his team measured the redshift of GN-z11. Recall that the cosmological (metagalactic) redshift is a decrease in radiation frequencies observed for all distant sources (galaxies, quasars), explained as the dynamic distance of these sources from each other and, in particular, from the Milky Way.
To study the GN-z11, the scientists used the ground-based spectrograph, an emission line measuring instrument called MOSFIRE, mounted on the Keck I telescope in Hawaii.
Let us recall that the emission spectrum, the emission spectrum, the emission spectrum is the relative intensity of the research object’s electromagnetic radiation on the frequency scale. It is usually studied in the infrared, visible, and ultraviolet ranges from highly heated substances.
MOSFIRE captured the emission lines of GN-z11 in detail, allowing the team to make a much more accurate estimate of the galaxy’s distance. As Kashikawa notes, when working with distances on these scales, it is unwise to use our familiar units of kilometers or even multiples of them. Instead, astronomers use a different value – the redshift number denoted z.
Kashikawa and his team have improved the galaxy’s z-value accuracy by 100 times. If subsequent observations confirm this, astronomers can confidently say that GN-z11 is the most distant galaxy ever discovered in the universe.