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\t\t\t\t\t\t11\/12\/2024<\/span> For the first time, the NASA\/ESA\/CSA James Webb Space Telescope has detected and \u2018weighed\u2019 a galaxy, in the early Universe, that has a mass that is similar to what our Milky Way galaxy\u2019s mass might have been at the same stage of development. Found at around 600 million years after the Big Bang, this lightweight galaxy, nicknamed the Firefly Sparkle, is gleaming with star clusters \u2013 10 in total \u2013 that researchers examined in great detail.\u00a0Other galaxies Webb has detected at this period in the history of the Universe are significantly more massive.<\/p>\n<\/div>\n \u201cI didn\u2019t think it would be possible to resolve a galaxy that existed so early in the Universe into so many distinct components, let alone find that its mass is similar to that of our own galaxy when it was in the process of forming,\u201d\u00a0said Lamiya Mowla, co-lead author of the paper and an assistant professor at Wellesley College in Massachusetts.\u00a0\u201cThere is so much going on inside this tiny galaxy, including so many different phases of star formation.\u201d<\/p>\n Webb was able to image the galaxy in sufficient detail for two reasons. One is a benefit of the cosmos: a massive foreground galaxy cluster radically enhanced the distant galaxy\u2019s appearance through a natural effect known as\u00a0gravitational lensing. And when combined with the telescope\u2019s power in high-resolution imaging of\u00a0infrared light, Webb delivered unprecedented new data about the galaxy\u2019s contents.<\/p>\n \u201cWithout the benefit of this gravitational lens, we would not be able to see this galaxy in such detail,\u201d\u00a0said Kartheik Iyer, co-lead author and NASA Hubble Fellow at Columbia University in New York.\u00a0\u201cWe knew to expect it based on current physics, but it\u2019s surprising that we actually saw it.\u201d<\/p>\n Lamiya, who spotted the galaxy in Webb\u2019s image, was drawn to its gleaming star clusters, because objects that sparkle typically indicate they are extremely clumpy and complicated. Since the galaxy looks like a ‘sparkle’ or a swarm of fireflies on a warm summer night, they named it the Firefly Sparkle galaxy.<\/p>\n<\/p><\/div>\n The research team modelled what the galaxy might have looked like if its image weren\u2019t stretched by gravitational lensing and discovered that it resembled an elongated raindrop. Suspended within it are two star clusters toward the top and eight toward the bottom.\u00a0\u201cOur reconstruction shows that clumps of actively forming stars are surrounded by diffuse light from other unresolved stars,\u201d\u00a0said Kartheik.\u00a0\u201cThis galaxy is literally in the process of assembling.\u201d<\/i><\/p>\n Webb\u2019s data show the Firefly Sparkle galaxy is on the smaller side, falling into the category of a low-mass galaxy. Billions of years will pass before it builds its full heft and a distinct shape. <\/i>\u201cMost of the other galaxies Webb has shown us aren\u2019t magnified or stretched, and we are not able to see their ‘building blocks’ separately. With Firefly Sparkle, we are witnessing a galaxy being assembled brick by brick,\u201d\u00a0Lamiya said<\/p>\n<\/p><\/div>\n Since the image of the galaxy is warped into a long arc, the researchers easily picked out 10 distinct star clusters, which are emitting the bulk of the galaxy\u2019s light. They are represented here in shades of pink, purple, and blue. Those colours in Webb\u2019s images and its supporting\u00a0spectra\u00a0confirmed that star formation didn\u2019t happen all at once in this galaxy, but was staggered in time.<\/p>\n \u201cThis galaxy has a diverse collection of star clusters, and it is remarkable that we can see them separately at such an early age of the Universe,\u201d\u00a0said Chris Willott of the National Research Council Canada, a co-author and the observation programme\u2019s principal investigator.\u00a0\u201cEach clump of stars is at a different stage of formation or evolution.\u201d<\/p>\n The galaxy\u2019s projected shape shows that its stars haven\u2019t settled into a central bulge or a thin, flattened disc, another piece of evidence that the galaxy is still forming.<\/p>\n<\/p><\/div>\n Researchers can\u2019t predict how this disorganised galaxy will build up and take shape over billions of years, but there are two galaxies that the team confirmed are ‘hanging out’ close to it and they may influence how\u00a0Firefly Sparkle builds mass over billions of years.<\/p>\n Firefly Sparkle is only 6500 light-years away from its first companion, and its second companion is separated by 42 000 light-years. For context, the fully formed Milky Way measures about 100 000 light-years across\u00a0\u2013 all three would fit inside it. Not only are its companions very close, the researchers also think that they are orbiting one another.<\/p>\n Each time one galaxy passes another, gas condenses and cools, allowing new stars to form in clumps.\u00a0\u201cIt has long been predicted that galaxies in the early Universe form through successive interactions and mergers with other tinier galaxies,\u201d\u00a0said Yoshihisa Asada, a co-author and doctoral student at Kyoto University in Japan. \u201cWe might be witnessing this process in action.\u201d<\/p>\n \u201cThis is just the first of many such galaxies JWST will discover, as we are only starting to use these cosmic microscopes\u201d, added team member Maru\u0161a Brada\u010d of the University of Ljubljana in Slovenia.\u00a0\u201cJust like microscopes let us see pollen grains from plants, the incredible resolution of Webb and the magnifying power of gravitational lensing let us see the small pieces inside galaxies. Our team is now analysing all early galaxies, and the results are all pointing in the same direction: we have yet to learn much more about how those early galaxies formed.\u201d<\/p>\n The team\u2019s research relied on data from Webb\u2019s\u00a0CAnadian NIRISS Unbiased Cluster Survey, which include near-infrared images from\u00a0NIRCam\u00a0(Near-InfraRed Camera) and spectra from the microshutter array aboard\u00a0NIRSpec\u00a0(Near-Infrared Spectrograph). The CANUCS data intentionally covered a field that the NASA\/ESA\u00a0Hubble Space Telescope imaged as part of its\u00a0Cluster Lensing And Supernova survey with Hubble\u00a0programme.<\/p>\n This work is published in the journal\u00a0Nature.<\/i><\/p>\n<\/p><\/div>\n \nMore information<\/b> Webb is an international partnership between NASA, ESA and the Canadian Space Agency (CSA).<\/p>\n Release on esawebb.org<\/p>\n \u00a0<\/p>\n \nContact:<\/b>
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\n\t\t\t\t\t\t\t\t<\/figcaption><\/figure>\n<\/p><\/div>\nReconstructing the galaxy\u2019s appearance<\/h2>\n
Stretched out and shining, ready for close analysis<\/h2>\n
\u2018Glowing\u2019 companions<\/h2>\n
Webb\u00a0is the largest, most powerful telescope ever launched into space. Under an international collaboration agreement, ESA provided the telescope\u2019s launch service, using the Ariane 5 launch vehicle. Working with partners, ESA was responsible for the development and qualification of Ariane 5 adaptations for the Webb mission and for the procurement of the launch service by Arianespace. ESA also provided the workhorse spectrograph\u00a0NIRSpec\u00a0and 50% of the mid-infrared instrument\u00a0MIRI, which was designed and built by a consortium of nationally funded European Institutes (The MIRI European Consortium) in partnership with JPL and the University of Arizona.<\/p>\n
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