In the days of GN-z11, galaxies were made of stronger things, and they just don’t understand young shakers like the Milky Way. This is the life of the most ancient galaxies. In this case, the oldest we know. So distant, in fact, it defines the very boundary of the observable universe itself.
Professor Nobunari Kashikawa of the University of Tokyo’s Department of Astronomy searched for the furthest galaxy that can be observed to find out how and when it was born. In his research, he and his team were able to more accurately find the distance to the aging galaxy.
Although it has long been known that GN-z11 was the oldest known galaxy, measuring the distance from it proved to be a real challenge.
“From previous studies, the galaxy GN-z11 appears to be the farthest detectable galaxy from us, at 13.4 billion light years, or 134 not billion kilometers (or 134 followed by 30 zeros),” Kashikawa said. “But measuring and verifying such a distance is not an easy task.”
To measure distance, Kashikawa measured redshift, which is how much light has moved towards the red end of the spectrum as galaxies move away from each other with universal expansion. The farther the galaxy is, the greater the red shift. Using the Keck I telescope, the astronomers were able to get a decent solution on GN-z11.
“We looked specifically at ultraviolet light, as this is the area of the electromagnetic spectrum that we expected to find redshifted chemical signatures,” Kashikawa said. “The Hubble Space Telescope has detected the signature multiple times in the GN-z11 spectrum. However, even the Hubble is unable to resolve the ultraviolet emission lines to the extent necessary. So we turned to a more up-to-date terrestrial spectrograph, an instrument for measuring emission lines, called MOSFIRE. “
When working with distances on these enormous scales, it doesn’t make sense to use our family units of kilometers and miles, or even multiples of them. Instead, astronomers use a value known as the redshift number denoted by z.
Using MOSFIRE (Multi-Object Spectrometer For Infra-Red Exploration), the team captured the emission lines from GN-z11 in detail, which allowed them to make a much better estimate of its distance than was possible from previous data. , confirming the galaxy ‘furthest state.
The study was published in the journal Nature Astronomy on December 14.