Astronomy: Milky Way is an "outlier" among similar galaxies
An extensive comparison of satellites of large galaxies has shown that our home galaxy is not as ordinary as we always thought.
(Image: Yao-Yuan Mao, with images from the DESI Legacy Surveys Sky Viewer)
Our Milky Way is apparently not at all as ordinary as previously assumed. This is the result of a detailed comparison with more than 100 similar galaxies, which revealed subtle differences, explains Stanford University in California. Above all, these could ensure that in future it is no longer simply assumed that our home galaxy is representative –, especially when it comes to the formation of galaxies.
Satellites point to a different development
For the study now presented, physicist Risa Wechsler began an investigation more than ten years ago dedicated to satellite galaxies. These are smaller companions around large galaxies such as our Milky Way. She and her team then identified a total of exactly 101 galaxies that are largely similar to our Milky Way. A precise comparison then revealed that the evolutionary history of our home galaxy differs from that of comparably large galaxies.
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Specifically, the team determined that galaxies like our Milky Way have between 0 and 13 satellite galaxies, with our home galaxy having four in between. But galaxies that have large satellites – such as our Large and Small Magellanic Clouds – would have more and more in total. The Milky Way is an "outlier" here. In addition, stars would normally still form in the small satellite galaxies, but not in those of the Milky Way. The group presents its findings in three research articles and argues that a wider range of objects should be included in research into the formation of galaxies.
(mho)
