Space scientists at the University of Leicester celebrate 15 years in space for ESA’s XMM-Newton satellite
Space scientists at the University of Leicester have this month been marking an important milestone for a space mission with a strong Leicester heritage – the 15th anniversary of the launch of the European Space Agency’s XMM-Newton satellite.
XMM-Newton, whose main task is the study of the hot and extreme Universe, carries advanced X-ray cameras designed and built at the University of Leicester together with three of the largest X-ray telescopes that have ever flown.
Launched on 10 December 1999, XMM-Newton has revolutionised many aspects of contemporary astrophysics. XMM-Newton’s observations, which are performed for the European and worldwide scientific community in response to competitive bids, cover all areas of astronomy from comets and planets within our solar system to the most distant quasars. Its seminal contributions include the analysis of black holes in orbiting close to normal stars in binary systems in the Milky Way and in our local group of galaxies, and the study of super-massive black holes, more than a million times the mass of our Sun, at the centre of the most distant galaxies, where they accrete and blow off super-heated gas. Studies performed with XMM-Newton have already produced almost 4000 scientific papers, making it the most productive of ESA’s missions to date.
Dr Steve Sembay, of the University’s Department of Physics and Astronomy, who has led one of the XMM-Newton instrument teams for the last five years said: “XMM-Newton has been an outstanding success, exceeding all expectations in terms of the performance and longevity of its science payload. The University of Leicester was the lead UK institution of the consortium that provided two of the three CCD-based cameras which make up the European Photon Imaging Camera (EPIC), the prime instrument on XMM-Newton. It is a testament to the skill of the scientists and engineers within the University that EPIC continues to return near maximum scientific performance after 15 years of operations in the harsh environment of space.”
The scientific highlights gleaned from XMM-Newton’s 15 years of discovery include the construction of the largest catalogues of cosmic X-ray emitting objects ever. Professor Mike Watson, who led the team that made the catalogues, said: “We are very proud to have made a significant contribution to our understanding of the Universe at X-ray wavelengths through the XMM-Newton catalogues. The latest “3XMM” catalogue released in 2013 contains over half a million entries and is a superb resource for exploring the high energy Universe.”
Another recent highlight, and indeed a completely unexpected result, came from a detailed study of the data from XMM-Newton that nobody else wanted, its background signal. Leicester scientist Dr Andy Read said: “We have discovered potential signatures of solar axions – Dark Matter particle candidates – via analysis of almost the entire XMM-Newton archive. This signal – a slow variation in the X-ray background – has no conventional explanation, but is consistent with the idea that axions might be produced in the core of the Sun and then convert into X-rays – detectable by XMM-Newton – in the magnetic field of the Earth. If confirmed, this could potentially open a window to new physics, and be truly ground-breaking in helping to identify Dark Matter and to understand the true X-ray sky.”
Reflecting on XMM-Newton’s 15 years of discovery, Professor Ken Pounds CBE,FRS, Emeritus Professor of Physics at the University of Leicester, said: “When XMM was launched 15 years ago one of the most challenging problems in astronomy was to understand why the mass of stars in a galaxy was often of order 1000 times that of the supermassive black hole lurking at its heart. The high sensitivity and spectral resolution of XMM’s EPIC X-ray camera (led by our own Martin Turner) has provided the answer by detecting powerful winds driven from close to the super-massive black hole that blows away the star-forming gas and simultaneously curtails the hole’s food supply. I am delighted to be amongst the Leicester scientists who have played a leading role in this research.”
Scientists around the world want the XMM-Newton observatory to keep working for many more years. Its replacement, called Athena, will not be launched before 2025. Fortunately, XMM-Newton is in good shape and has plenty of manouevre gas to keep it observing for quite some time yet. The high international demand for its observations will mean that Leicester’s X-ray cameras have plenty more work to do.
