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Principale » Large-scale galaxy alignments are several billion years old

Large-scale galaxy alignments are several billion years old

14 Juin 2017

Therefore, the galaxies and their clusters needs to be tapped and distributed in space in a similar way.

The work was led by Lowell Observatory astronomer Michael West, who together with his collaborators used Hubble Space Telescope images of 65 galaxy clusters located billions of light-years away to study the orientation of the massive elliptical galaxies in the centers of these clusters.

These observations, as the authors of the open, do not rule out the possibility that the galaxy could line up in a line after their formation, however, this "migration" should be very fast, nearly impossible from the point of view of theories about the origin and movement of galaxies and their clusters.

"It's well established that the major axes of BCGs are often elongated in the same direction as the galaxy cluster in which they reside and, furthermore, that clusters themselves are aligned with their neighbors, a remarkable coherence of structures over many millions of light years".

With this motivation, Dr. They showed for the first time that the largest galaxies in these systems were already aligned with their surroundings when the universe was only 1/3 of its current age.

"It's an important new piece of the puzzle, because it says that whatever caused these alignments happened early", Dr.

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In May of 2015, an worldwide team of astronomers led by Yale University and the University of California-Santa Cruz observed a primordial galaxy shown at the top of the page that pushes back the cosmic frontier of galaxy exploration to a time when the universe was only 5% of its present age.

In addition to West, the team consists of Roberto De Propris of the University of Turku, Malcolm Bremer and Steven Phillipps, both at the University of Bristol.

The team is eager to look further back in time by observing more remote clusters. But when and how these alignments occurred remains a mystery.

Another theory suggests that, given enough time, gravity's relentless tug will slowly reorient the largest galaxies until they are aligned with the surrounding distribution of galaxies. While the discovery of galaxy alignments at early epochs does not rule out either scenario, it does place increasingly tight time constraints.

Results of the study were published on June 12, 2017 via Advance Online Publication on Nature Astronomy's website. Despite the precision achievable with Hubble, however, this will be challenging, as even massive galaxies appear fainter and smaller as the distance between Earth and these clusters grows.

Large-scale galaxy alignments are several billion years old