It’s official! Astronomers confirm GN-z11 is the most distant galaxy ever seen – SYFY WIRE

Posted: December 19, 2020 at 8:10 am

Back in March of 2016, NASA/ESA'sHubble Space Telescopespotted the most distant heavenly object ever seen in the great universalvoid:an extremely remote galaxy silently spinning beyond the constellation Ursa Major, some 13.4 billion light-years away.

Officially catalogued asGN-z11, this ancient galactic raritywas captured in the same form as when itexisted nearly420 million years followingthe Big Bang, making it one of the first galaxies formed afterthat cataclysmic event.

Now a new study presentedby astronomers at the University of Tokyo and Peking University hasaccurately measured the redshift of GN-z11.In a new paper published in Nature Astronomy, researchersconfirmedthat this far-off galaxy is indeedthe furthestobservable object witnessedby mankind.

From previous studies,GN-z11seems to be the farthest detectable galaxy from us, at 13.4 billion light years, explainedco-lead authorDr. Nobunari Kashikawa,Department of Astronomy at the University of Tokyo. But measuring and verifying such a distance is not an easy task.

A key toolfor astrophysicists, redshift is a shift toward longer wavelengths inspectral lines emitted by distant galaxies and celestial objects. It'sthe result of the universe expanding,andsubsequently theobject moving away from the Earth.

According to the research paper, the team targeted chemical signatures known as emission lineswhich imprint uniquepatterns in the light streaming in from distant objectsfor their calculations.

By measuring how stretched these telltale signatures are, we can deduce how far the light must have traveled, thus giving away the distance from the target galaxy," Kashikawa added. We looked at ultraviolet light specifically, as that is the area of the electromagnetic spectrum we expected to find the redshifted chemical signatures."

While the originaldata collected by Hubblerecordedthe signature numeroustimes in the spectrum of GN-z11, scientists still required more precisedetails of these ultraviolet emission lines to lock in the record-breaking find.

By employingnear-infrared spectroscopic observations usingtheMOSFIRE spectrograph installed on theKeck I telescopeat the W.M. Keck Observatory in Hawaii, Kashikawa and his colleagues discovered that GN-z11's redshift was officially determined to bez=10.957.

MOSFIRE captured the emission lines from GN-z11 in detail, which allowed us to make a much better estimation on its distance than was possible from previous data, Kashikawa and his crew noted.

In addtional news generated from this remote galaxy, a team led byLinhua Jiang ofPeking University in Beijing, Chinawasrecently using the Keck Observatory in Hawaii to study GN-z11. Theyobserveda massive explosion emanating from the faint celestial location.The galaxy appearedhundredof times brighter for just under 3 minutes, and was likely caused by an intense gamma-ray burst when one of its stars exploded in a brilliant supernova.

If verified, this would go down asthe oldest gamma-ray burst ever spotted, something not normally observed in galaxies born in the fledgling universe.

"This is because gamma-ray bursts should be extremely rare," saidJiang.The probability to detect a gamma-ray burst [in a particular galaxy] is near to zero, he says. If you observed a galaxy for a million years, youd probably find [only] a few gamma-ray bursts. Thats why its so surprising.

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It's official! Astronomers confirm GN-z11 is the most distant galaxy ever seen - SYFY WIRE

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