Members of the astrophysics group (Mark Birkinshaw, Malcolm Bremer, Paul Giles, Ben Maughan and recently graduated PhD student Kate Husband) contributed to 6 papers published in a special issue of Astronomy and Astrophysics on 15 December 2015 to mark the first science release of the XXL survey. XXL is a new, sensitive survey of the X-ray sky, optimised to detect clusters of galaxies over the last 10 billion years of cosmic history. It is the largest ever science programme performed with the XMM-Newton observatory and is a collaboration of more than 100 international researchers (Birkinshaw is UK PI).
Giles and Maughan led paper III of the series, in which they showed that distant galaxy clusters, seen in the early Universe, are surprisingly similar to their nearby counterparts. Once the effects of the cosmic expansion have been taken into account, there are no strong signs of evolution in galaxy clusters over the last half of the Universe's lifetime.
A new panorama of the X-ray universe
XMM image of the southern XXL panorama. This is one half of the full XXL survey; along with the northern field XXL is the largest view of the deep X-ray sky obtained to date. The size of the full moon is shown for comparison. Most of the bright X-ray sources seen in this image are active galactic nuclei (more than 12,000 have been detected in this image). The red circles show the clusters of galaxies that were found in this image and that were used for the investigation of the evolution of galaxy clusters. The XXL survey S. Snowden, L. Faccioli, F. Pacaud
19 January 2016
A panorama of the X-ray sky has been completed by an international team of more than 100 scientists, providing new insights into the nature of the Universe.