Galaxy GN-z11 is so distant that it defines the very boundary of the observable Universe. A team of scientists hopes
Professor Nobunari Kashikawa of the Facultyin astronomy at the University of Tokyo has long searched for the most distant galaxy that can be observed to find out how and when it appeared.
“Judging by previous studies, the galaxyGN-z11 appears to be the farthest discovered galaxy from us. It is located at a distance of 13.4 billion light years or 134 nonillion kilometers (that's 134 followed by 30 zeros),” Kashikawa explains. “But measuring and checking such a distance is not an easy task.”
Kashikawa and his team measured the redshiftGN-z11. Recall that the cosmological (metagalactic) redshift is a decrease in radiation frequencies observed for all distant sources (galaxies, quasars), explained as the dynamic removal 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, which is mounted on the Keck I telescope in Hawaii.
(Above) The arrow points to the farthestgalaxy in the universe. (Bottom) Infrared carbon emission lines. When it left the galaxy, the signal was ultraviolet light in the 0.2 micrometer region, but it was red-shifted and stretched 10 times, down to about 2.28 micrometer. Credit: Kashikawa et al.
Let us recall, emission spectrum, spectrumradiation, emission spectrum is the relative intensity of the electromagnetic radiation of the object of study on a frequency scale. Usually studied in the infrared, visible and ultraviolet ranges from a highly heated substance.
MOSFIRE recorded emission lines in detailGN-z11, which allowed the team to make a much more accurate estimate of the distance to the galaxy. As Kashikawa notes, when dealing with distances at these scales, it is unwise to use our familiar units of kilometers or even multiples thereof. Instead, astronomers use another value, the redshift number, denoted z.
Kashikawa and his team have improved accuracyz values of the galaxy are 100 times. If subsequent observations confirm this, astronomers can say with confidence that GN-z11 is the most distant galaxy ever discovered in the Universe.
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