“James Webb” discovers six small galaxies within a giant ancient galaxy

A space observatory is named after him. James Webb made his one of the most important discoveries in astronomy in recent years. The largest ancient galaxy, HFLS3, discovered in 2013 and only 880 million years old, was not what scientists claimed. As Webb’s observations showed, HFLS3 is an early collision of six young galaxies.

The early universe was a tumultuous time. During the first two billion years after the Big Bang, about 13.8 billion years ago, star formation increased significantly and galaxies flared up in the darkness, collided and grew. But try to recognize the details of our time. It’s no surprise that because scientific instruments are imperfect, we can’t always understand what was happening in a particular region of the universe at a particular time. His discovery of the HFLS3 “galaxy” in 2013 surprised scientists. This object was discovered using data from the Herschel Space Telescope. It was at the very beginning of the universe, in the age of reionization, and was producing stars at an astonishing rate of about 3,000 solar masses per year. By comparison, our Milky Way galaxy produces stars at a rate of up to 8 solar masses per year. This was despite the fact that HFLS3 and the Milky Way galaxy have approximately the same mass.

What happened in HFLS3 cannot be explained by current cosmology. Subsequent observations by Herschel and the involvement of another space telescope, Hubble, suggested that HFLS3 was not what it seemed. Clearer conditions were obtained when the James Webb Telescope observed this part of the sky in his fall of 2022. A team of astrophysicists led by Oxford University scientist Gareth Jones analyzed data from the HFLS3 observations and produced a scientific paper that has not yet been peer-reviewed for publication in the journal Astronomy & Astrophysics. The paper can be viewed on the arXiv website.

Scientists found that HFLS3 consists of three pairs of small galaxies spinning in a strange cosmic dance that leads to an inevitable collision in a universe just 36,000 light-years across. This collision is thought to have occurred within a billion years after it was observed, which is considered a relatively short period of time for something as large as a galactic collision. Because the paired galaxies are so close to each other, gravitational interactions mix their star-forming material and trigger star formation. This also explains how new stars are born at such a fast rate. And the discovery provides a fascinating snapshot of how galaxies interact and grow during a period known as the “dawn of the universe.”

source: https://arxiv.org/abs/2308.16620