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James Webb Telescope captures tiny galaxies that reveal big secret

James Webb Telescope captures tiny galaxies that reveal big secret

India Today13-06-2025
Using data from NASA's James Webb Space Telescope (JWST), astronomers have identified dozens of small, starburst galaxies that played a pivotal role in transforming the early universe during a period known as cosmic reionisation.These tiny galaxies, though small in size, emitted powerful ultraviolet light that helped clear the fog of neutral hydrogen gas enveloping the universe's first billion years, enabling the universe to become transparent and evolve into its current state.advertisementThe discovery, presented by Isak Wold, an assistant research scientist at Catholic University of America and Nasa's Goddard Space Flight Center, was made possible by the unprecedented sensitivity of JWST's instruments, particularly the Near-Infrared Camera (NIRCam) and Near-Infrared Spectrograph (NIRSpec).
The team analysed images from the UNCOVER observing program, which focused on the massive galaxy cluster Abell 2744, also known as Pandora's cluster. This cluster's immense gravity acts as a natural lens, magnifying distant galaxies and extending Webb's observational reach about 4 billion light-years away.The galaxies identified date back to when the universe was roughly 800 million years old, an epoch astronomers call redshift 7.During this time, vigorous star formation episodes—starbursts—occurred in these low-mass galaxies, producing intense ultraviolet radiation. This radiation ionised the surrounding hydrogen gas by stripping electrons from atoms, a process essential for the universe's transition from opaque to transparent.advertisementThe researchers detected a distinctive green emission line from doubly ionised oxygen, originally visible light stretched into the infrared spectrum due to cosmic expansion, confirming the presence of these energetic processes.
The project mapped a giant galaxy cluster known as Abell 2744, nicknamed Pandora's cluster. (Photo: Nasa)
'These galaxies punch well above their weight,' said Wold. To build a galaxy with the stellar mass of our Milky Way, one would need between 2,000 and 200,000 of these small galaxies. Yet, their abundance and ultraviolet output are sufficient to account for the entire reionisation process, assuming they release ultraviolet light at efficiencies similar to comparable galaxies in the present universe.This finding sheds light on a longstanding cosmic mystery about what powered reionisation, emphasising the outsised role of small, star-forming galaxies in shaping the universe's early evolution.The James Webb Space Telescope continues to revolutionise our understanding of cosmic history by revealing the building blocks of galaxies from the dawn of timeMust Watch
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Major reports about how climate change affects U.S. removed from websites
Major reports about how climate change affects U.S. removed from websites

The Hindu

time2 hours ago

  • The Hindu

Major reports about how climate change affects U.S. removed from websites

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Shukla In space: Benefits far outweigh cost, says Isro chief
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  • Time of India

Shukla In space: Benefits far outweigh cost, says Isro chief

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Anil Menon: Who Is NASA Astronaut Whose Wife Went On Private Spacewalk Mission In 2024?
Anil Menon: Who Is NASA Astronaut Whose Wife Went On Private Spacewalk Mission In 2024?

News18

time5 hours ago

  • News18

Anil Menon: Who Is NASA Astronaut Whose Wife Went On Private Spacewalk Mission In 2024?

Last Updated: NASA said it is sending Anil Menon for his first mission to the International Space Station as a flight engineer and Expedition 75 crew member in June 2026 Selected to be an astronaut in 2021, Anil Menon will make his first trip to space as a flight engineer and Expedition 75 crew member in June 2026. NASA said it is sending Menon for his first mission to the International Space Station next year, and he will be launching aboard the Roscosmos Soyuz MS-29 spacecraft with cosmonauts Pyotr Dubrov and Anna Kikina. The premier space agency said after launching from the Baikonur Cosmodrome in Kazakhstan, the trio will spend approximately eight months aboard the orbiting laboratory. Anil Menon, who is a NASA Artemis astronaut candidate graduate, will conduct scientific investigations and technology demonstrations to help prepare humans for future space missions. Fun fact: his wife Anna Menon, who worked for NASA before joining SpaceX, went for a private spacewalk mission last year. She is a lead space operations engineer at Elon Musk's company and has written a children's book about space titled Kisses from Space. Like his wife, he has also worked for SpaceX, serving as the first flight surgeon while helping to launch the first crewed Dragon spacecraft on NASA's SpaceX Demo-2 mission and building SpaceX's medical organisation to support humans on future missions. He served as a crew flight surgeon for both SpaceX flights and NASA expeditions aboard the space station. Menon graduated with the 23rd astronaut class in 2024. He began preparing for his first space station flight assignment after completing initial astronaut candidate training. He still practises emergency medicine at Memorial Hermann's Texas Medical Center and teaches residents at the University of Texas residency programme in his spare time. First Published:

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