"Large galaxies" refers to giant groups of billions of stars, planets, and other celestial objects that are bound together by gravity. They are much bigger and more massive than smaller galaxies, and can range in shape and structure. Full definition
The discovery provides new details about the emergence of large galaxies and the role that dark matter plays in assembling the most massive structures in the universe. (sciencedaily.com)
In the standard low - density universe, small fluctuations have trouble growing into large galaxies. (newscientist.com)