Discovery of the Milky Way's most distant 'twin' galaxy

Image of Zhulong, the most distant spiral galaxy ever seen, discovered by JWST - Photo: NASA/CSA/ESA

This galaxy, named Zhulong (Zhulong), existed just 1 billion years after the Big Bang, but already shows an incredibly evolved structure with an old central nucleus, a large star-forming disk, and clearly defined spiral arms.

Zhu Long, which means "Torch Dragon" in Chinese mythology, was discovered using data from the James Webb Space Telescope (JWST) PANORAMIC survey.

What is special about Chuc Long is its remarkable similarity to the Milky Way in shape, size and stellar mass.

Zhu Long's disk spans more than 60,000 light-years, about the same as our galaxy, and contains more than 100 billion times the mass of the Sun.

This discovery poses a major challenge to current theories of galaxy formation.

Previously, astronomers believed that spiral structures took billions of years to develop, and that giant galaxies only emerged after many smaller galaxies merged together over time. However, the existence of Zhulong forces scientists to reconsider how galaxies could form and grow so quickly in the early universe.

Dr Christina Williams, astronomer at NOIRLab and PANORAMIC programme leader, said the discovery was made possible by JWST's unique "pure parallel" mode - an efficient strategy for collecting high-quality images while JWST's main instrument is observing another target.

This method allows JWST to map large areas of the sky, which is necessary to detect giant galaxies that are very rare.

Zoomed-in image of Zhulong, the most distant spiral galaxy ever seen, discovered by JWST - Photo: NASA/CSA/ESA

Professor Pascal Oesch, co-leader of the PANORAMIC program at UNIGE, stressed that this discovery shows that JWST is fundamentally changing our view of the early universe. Further observations from JWST and the Atacama Large Millimeter-Wave Observatory (ALMA) will help confirm Zhulong's properties and reveal more about its formation history.

As JWST's large-scale surveys continue, astronomers expect to find more similar galaxies, providing new insights into the complex processes that shaped galaxies in the early universe.

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Source: https://tuoitre.vn/phat-hien-thien-ha-em-song-sinh-xa-nhat-cua-dai-ngan-ha-20250417093407593.htm