REBELS-25.. The galaxy that challenges understanding of the universe – DW – 08/10/2024

Using the Atacama Large Millimeter/submillimeter Array (ALMA), the world’s largest astronomy project based in Chile’s Llano de Chajnantor, a team of researchers has discovered a galaxy that challenges current knowledge about the formation of these systems.

The European Southern Observatory (ESO), associated with the ALMA project, reported last Monday (10/7/2024) that the new galaxy, called REBELS-25, presents an “ordered” shape like existing galaxies, although it reflects what the universe used to be like. When “it was only 700 million years old”

Considered an “early galaxy,” it is common for this type to have a more chaotic appearance, but Rebels-25 is similar in shape to the Milky Way, and features a rotating disk with structures defined as spiral arms.

“These turbulent primordial galaxies are merging with each other and evolving into smoother shapes at an incredibly slow rate. Current theories suggest that for a galaxy to be as organized as our Milky Way – a rotating disk with structures organized like spiral arms – it would take billions of years of evolution.” “It has passed.” He confirms this in a statement.

“However, the discovery of REBELS-25 calls this time scale into question,” adds the foundation, which is based in Garching, Bavaria, Germany.

The challenge of understanding the universe

The study has been accepted for publication in Monthly Notices of the Royal Astronomical SocietyAstronomers have discovered that REBELS-25 is the most distant rotating disk galaxy ever discovered. As the press release states, “The light reaching us from this galaxy was emitted when the universe was only 700 million years old, barely five percent of its current age (13.8 billion), so the ordered rotation of REBELS-25 is unexpected.” .

“Seeing a galaxy with many similarities to our own Milky Way, which is strongly spin-dominated, challenges our understanding of how quickly galaxies in the early universe evolved into the organized galaxies in the universe today,” says Lucy Rolland, a doctoral student at Leiden University. (Netherlands) and first author of the study in the same press release.

ESO researchers previously detected the existence of REBELS-25 thanks to ALMA, but the images they obtained were not as revealing as the ones they have now of this early galaxy.

ALMA, the largest such device in the world, located 5,000 meters above sea level in Chile’s Atacama Desert, has been operating for just over a decade; A time that helped reveal many of the mysteries of the sky as well as helping to produce, among other things, the first image of a black hole.

aa (efe, european southern observatory)