Four years ago, researchers discovered galaxy GN-z11. Hubble observations suggested that its light came from less than 500 million years after the Big Bang, present 13.4 billion years ago. New research now confirms this record-breaking finding.
As reported in Nature Astronomy, the galaxy was in place when the Universe was just 420 million years old, about 3 percent of its current age. This confirms it as the furthest-away galaxy on record, more distant than the previous record holder. The new observations obtained by the Keck I telescope were able to highlight specific emission lines, providing important insights beyond the distance confirmation.
The galaxy is very luminous, full of young bright stars, which is what made it possible for it to be detected by Hubble in the first place. It has just a few percent of the mass of stars in the Milky Way, and it is 25 times smaller. But compared to other objects in the early universe it is moderately massive, and researchers believe it is experiencing a period of intense star formation at a rate over 25 times faster than our galaxy. Again, this is surprising for an object so close to the formation of the universe.
The team believes that the bulk of its stars formed within the last 70 million years from the observations. This really underscores why it is an absolutely amazing finding. The first stars in the universe are expected to have formed between 100 and 250 million years after the Big Bang. This galaxy is the first window to an epoch of the universe we still know so little about.
The observations also highlighted the presence of carbon and oxygen in this galaxy. The strong carbon emission particularly could be due to an enhancement of this element very early in the history of the cosmos, or that the galaxy has a supermassive black hole active at its core. Both scenarios will require further study.
GN-z11 is a very important object, but its record-breaking status might not hold for long. Hubble’s successor the James Webb Space Telescope is expected to launch in October. The new instrument will be the most powerful and most complex space telescope ever, and it is designed also to look for galaxies as far away as this one.
Findings out if GN-z11 is an outlier or a common object is maybe just a few years away.