Galaxies are locked in place by their surroundings
Galaxies can be used as tracers for numerous characteristics of the universe, including the “cosmic web” of hydrogen gas that connects galaxies and follows the distribution of dark matter filaments throughout the cosmos. Looking at where galaxies sit sheds light on these otherwise invisible structures, while also providing clues about the amount of mass in galaxies and how they influence their neighbors over time. Now, astronomers have traced the alignment of massive galaxies back 10 billion years, showing these objects have been in tune with their environment since the universe was just one-third its current age.
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