Galactic Whiz
In the young universe, some galaxy clusters grew faster than expected. The giants challenge the standard cosmological model.
Galaxies also follow a life cycle. They form once enough gas and stars have accumulated to form a coherent structure. This happens either in the form of a single, slowly growing accumulation of matter or by the collision of several such clouds. Over the course of their existence, new stars are constantly being formed from the gas supply, which emit intense ultraviolet radiation - a typical characteristic of young, bright and hot specimens. As they age, they emit light with longer wavelengths. In astrophysical jargon, when a galaxy contains mostly reddish objects and little to no longer glows in the ultraviolet region of the spectrum, we call it "red and dead." At the end of its life, the galaxy will become a rounded blob, provided it has enough mass. Then it is called "elliptical" because of its shape and it hardly produces any new stars.
In a radius of about 300 to 600 million light-years, astronomers see a number of such groups of mature galaxies that have gravitationally bound together and formed large structures. These so-called clusters contain the remnants of the most massive galaxies ever formed. Hundreds to thousands of them are slowly circling each other here.
Most galaxy clusters seem to have existed when the universe was only half "Image" as it is today. The stars it contains should therefore have been born in the early cosmos … alt="
