Discovery of the longest gas strip in the universe, connecting two galaxies

Astronomers have discovered a giant 1.6 million light-year-long band of hydrogen gas connecting two dwarf galaxies. The discovery opens up new perspectives on how galaxies interact and evolve.

Composite image shows a diffuse gas "bridge" connecting two dwarf galaxies - Source: Perimeter Institute

In a statement on September 24, the International Centre for Radio Astronomy Research (ICRAR) based at the University of Western Australia (UWA) said that researchers had discovered a giant gas structure spanning 185,000 light-years, connecting two galaxies NGC 4532 and DDO 137. These galaxies are located 53 million light-years from Earth.

The study, published in the Monthly Notices of the Royal Astronomical Society (RAS), also revealed that the gas streak has a giant tail that stretches 1.6 million light-years, making it the longest gas tail ever observed.

According to Professor Lister Staveley-Smith - research team leader and astronomer at ICRAR UWA, this discovery marks an important step forward in understanding how galaxies interact.

According to him, tidal forces between the two galaxies NGC 4532 and DDO 137, together with their proximity to the Virgo Cluster – a giant collection of galaxies – play a crucial role in the observed aerodynamics.

"As the galaxies orbit each other and move into the hot gas surrounding the Virgo cluster, which is 200 times hotter than the surface of the Sun, they experience a pressure collision that causes the gas in the galaxies to separate and become heated," he explained.

The professor compared this phenomenon to the phenomenon of a satellite burning up when re-entering the Earth's atmosphere, but the difference is that it lasts for billions of years.

According to the researcher, the electron density and the speed at which galaxies fall into hot gas are enough to explain why a large amount of gas is pushed out of galaxies and concentrated in the connecting gas band as well as the surrounding areas.

Professor Kenji Bekki, co-author of the study and astrophysicist at ICRAR UWA, said neutral hydrogen plays a key role in the formation of stars, so the discovery is fundamental to understanding how galaxies interact and evolve, especially in dense environments such as galaxy clusters.

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Source: https://tuoitre.vn/phat-hien-dai-khi-dai-nhat-vu-tru-noi-2-thien-ha-20250924205526248.htm