Space.com writes that astronomers have discovered the most distant (and oldest) galaxy ever seen. The GN-z11 galaxy does not have a spectacular name, but it looks very special.
Led by Nobunari Kashikawa, a professor in the Department of Astronomy at the University of Tokyo, astronomers are working to find a galaxy to determine when and how the universe formed. “From previous studies, the GN-Z11 galaxy appears to be 13.4 billion light-years away or 134 kilometers (the farthest galaxy we can detect (i.e. 134 consecutive 30 zeros ‘,'” Kashikawa said. If further observations confirm their discovery, GN-z11 will officially become the most distant galaxy ever observed.
“But measuring and verifying such a distance is not an easy task,” he said. To determine how far GN-Z11 is from Earth, Kashikawa’s team studied the red change of the galaxy – how far light extends. , Or in other words, moved towards the red end of the electromagnetic spectrum due to the Doppler effect. In general, the farther an object is from Earth, the more light it will move towards the red end of the spectrum. In addition, the team analyzed the emission lines of GN-z11 – chemical signatures that can be seen in light from cosmic objects.
By studying these signatures in detail, the team was able to determine how far light from GN-Z11 must have traveled before it reached us. “We particularly looked at ultraviolet light because it was part of the electromagnetic spectrum, and we expected the chemical signatures to turn red,” Kashikawa noted. -Z11 “. However,” even Hubble could not determine the transmission lines we needed. So, to measure the emission lines, we turned to a modern underground-based spectrograph called the MOSFIRE from the Keck I telescope in Hawaii. The new study was published in the December 14 issue of the journal Nature Astronomy.