{"id":27521,"date":"2025-04-17T12:33:09","date_gmt":"2025-04-17T12:33:09","guid":{"rendered":"https:\/\/www.europesays.com\/uk\/27521\/"},"modified":"2025-04-17T12:33:09","modified_gmt":"2025-04-17T12:33:09","slug":"meet-zhulong-the-milky-way-twin-that-shakes-up-our-cosmic-timeline-sciencealert","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/uk\/27521\/","title":{"rendered":"Meet Zh\u00fal\u00f3ng, The Milky Way ‘Twin’ That Shakes Up Our Cosmic Timeline : ScienceAlert"},"content":{"rendered":"

Back when the Universe was new, following the Big Bang<\/a> some 13.8 billion years ago, galaxies took a bit of time to assemble themselves from the surrounding primordial soup.<\/p>\n

A new discovery right at the end of the Cosmic Dawn is challenging how long we thought that assembly took. JWST has spotted a huge, ultramassive galaxy as it appeared 12.8 billion years ago, so intricately structured that it can only belong to the most spectacular category of galaxies: the grand design spiral.<\/p>\n

The galaxy’s name is Zh\u00fal\u00f3ng, after the Torch Dragon of Chinese myth<\/a>, and its discovery has now been detailed in Astronomy & Astrophysics<\/a>.<\/p>\n

“Zh\u00fal\u00f3ng shows that mature galaxies emerged much earlier than expected in the first billion years after the Big Bang,” writes<\/a> a team led by astronomer Mengyuan Xiao of the University of Geneva in Switzerland.<\/p>\n

“Our finding offers key constraints for models of massive galaxy formation and the origin of spiral structures in the early universe.”<\/p>\n

\"GargantuanMorphological modeling of Zh\u00fal\u00f3ng. (Xiao et al., arXiv<\/a>, 2024)<\/p>\n

In the Universe around us today, galaxies come in a number of different shapes and sizes. Lenticular galaxies are sort of blobby and formless, while spiral galaxies have defined spiral arms curving out from their centers.<\/p>\n

The grand design spiral galaxy is the most magnificently structured<\/a> sort of galaxy, with prominent, well-formed and visible spiral arms curving away from a bright, well-defined galactic center; almost the platonic ideal<\/a> of what a spiral galaxy should look like.<\/p>\n

We don’t have a clear idea about when spiral galaxies first started to come together in the Universe, but they’re pretty rare the further back in space-time we peer, and practically absent more than about 11.5 billion years ago.<\/p>\n

Zh\u00fal\u00f3ng was discovered serendipitously in data collected by JWST for its PANORAMIC survey<\/a>, an observation campaign to observe galaxies in the Cosmic Dawn, the first billion years after the Big Bang.<\/p>\n

Although the survey has spotted other massive galaxies, Zh\u00fal\u00f3ng, the team says, is truly incredible.<\/p>\n

“It has a striking evolved morphology: a quiescent-like classical bulge + star-forming stellar disk + grand-design spiral arms (defined as spiral structures spanning the whole galaxy, from the nucleus to outskirts, with spiral arms starting at diametrically opposite points), already at 1 billion years after the Big Bang,” they write in their paper<\/a>.<\/p>\n

\"GargantuanThe morphology of Zh\u00fal\u00f3ng. (Xiao et al., arXiv<\/a>, 2024)<\/p>\n

In addition, it’s quite large for a galaxy in the early Universe, measuring some 62,000 light-years in diameter, with a mass comparable to that of the Milky Way.<\/p>\n

“What makes Zh\u00fal\u00f3ng stand out is just how much it resembles the Milky Way in shape, size and stellar mass,” Xiao says<\/a>.<\/p>\n

The black hole<\/a> in its center seems to be quiescent, suggesting that the star formation rate of between 20 and 155 solar masses per year is slowing.<\/p>\n

All together, the data indicate a galaxy that has gone through the throes of formation and is settling down into a sedate, well-defined structure.<\/p>\n

The researchers believe that Zh\u00fal\u00f3ng represents the earliest example of a spiral galaxy seen to date. This suggests that a Milky Way-like galaxy<\/a> can form far faster than we thought \u2013 around 10 times faster than such formation would take place in the local Universe.<\/p>\n

“The presence of all of these properties makes Zh\u00fal\u00f3ng very exceptional,” the researchers write<\/a>, “indicating the rapid formation and morphological evolution of massive galaxies in the early Universe.”<\/p>\n

The discovery has been published in Astronomy & Astrophysics<\/a>.<\/p>\n

An earlier version of this article was published in January 2025.<\/p>\n","protected":false},"excerpt":{"rendered":"Back when the Universe was new, following the Big Bang some 13.8 billion years ago, galaxies took a…\n","protected":false},"author":2,"featured_media":27522,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3845],"tags":[120,74,70,16,15],"class_list":{"0":"post-27521","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-physics","8":"tag-msft-content","9":"tag-physics","10":"tag-science","11":"tag-uk","12":"tag-united-kingdom"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@uk\/114353327570212162","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/27521","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/comments?post=27521"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/27521\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media\/27522"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media?parent=27521"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/categories?post=27521"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/tags?post=27521"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}