A strange galaxy in the early universe lived fast and died young. It is the most distant 鈥渄ead鈥� galaxy, meaning it is no longer forming any new stars, ever spotted.
The galaxy JADES-GS+53.15508-27.80178 was discovered in 2010, but astronomers at the time were not able to characterise it in detail. at the University of Cambridge and his colleagues observed it again with the James Webb Space Telescope (JWST) and found that its star formation seems to have been quenched.
This is unusual because the galaxy is so far away that we see it as it was only 700 million years after the big bang. 鈥淭here is lots of gas in the early universe, and gas fuels star formation. So seeing a dead galaxy at such an early epoch means that there must be something actively preventing it from forming stars,鈥� says D鈥橢ugenio. 鈥淭hat is very surprising.鈥�
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The researchers estimate that the galaxy鈥檚 star-forming activity only lasted between 10 million and 50 million years, a much shorter working lifetime compared with otherwise similar galaxies nearby. It is not yet clear why star formation there happened so rapidly and then ceased just as quickly 鈥� but there are two potential explanations.
The first idea is that when stars form, they create huge amounts of radiation and powerful winds before they explode. All this turbulence could have blown the gas out of the galaxy, stopping star formation. The other possible solution is that an active black hole at the galaxy鈥檚 centre similarly produced strong winds that blasted the gas away. Strangely, if either one of these processes did occur, they must have unfolded faster in the early universe than they do today.
Despite this galaxy鈥檚 unusual inactivity, all hope is not yet lost. 鈥淕alaxies, especially at these early epochs, may rejuvenate and start forming stars again 鈥� we don鈥檛 know what will happen,鈥� says D鈥橢ugenio. The researchers are now preparing to look for more galaxies like this one in hopes of explaining its oddly premature death.
Nature
