Some consider the Hubble Space Telescope’s “deep field” images among the observatory’s most profound achievements, showing the cosmos is populated by countless galaxies across timescales stretching back to within a few hundred million years of the Big Bang. This Hubble look at galaxy cluster S 295, dominating the central region of this image, offers an equally mesmerising view with a wide range of galaxies mingled with foreground stars. The combined gravity of the galaxy cluster distorts the space around it, causing the light of background galaxies to smear out in variety of shapes. Says the European Space Agency’s “picture of the week” description: “As well as providing astronomers with a natural magnifying glass with which to study distant galaxies, gravitational lensing has subtly framed the centre of this image, producing a visually striking scene.”
A team of international scientists, led by astronomers from Cardiff University, has shown for the first time that galaxies can change their structure over the course of their lifetime. The researchers have shown that a large proportion of galaxies have undergone a major ‘metamorphosis’ since they were initially formed after the Big Bang.
Galaxy clusters, which consist of thousands of galaxies, are important for exploring dark matter because they reside in a region where such matter is much denser than average. Scientists believe that the heavier a cluster is, the more dark matter it has in its environment. But new research suggests the connection is more complicated than that.