XMM-Newton: It was 20 years ago today...

Tuesday 10 December 2019 is the 20th anniversary of the launch of XMM-Newton, one of the most important astronomical observatories ever sent into orbit. The University of Leicester has been part of the XMM-Newton project since the start and is joining in the global celebrations this week for a fantastic scientific achievement.

From design, cutting metal, building electronics and detectors, optics and ground testing and then two decades of ground-breaking astrophysics research using data from the Leicester-built instruments, our School of Physics and Astronomy has played an integral part in this hugely successful ESA mission.

Working with partner institutions in the UK, Germany, Italy and France, Leicester supplied a set of three X-ray CCD cameras, together comprising the European Photon Imaging Camera (EPIC). Two of the cameras are MOS (Metal Oxide Semi-conductor) CCD arrays which were mostly built in Leicester. The Principal Investigator for the EPIC camera was the late Professor Martin Turner from 1997 until 2009, and is now Dr Steven Sembay, who chaired the whole EPIC calibration team until those duties were taken over by ESA.

Dr Steven Sembay said: “Even after 20 years in space the MOS cameras have seen very little degradation in their efficiency despite the harsh radiation environment of space. This is testament to how well the spacecraft and instruments of XMM-Newton were designed.”

Equally important for the success of XMM-Newton has been the XMM-Newton Survey Science Centre (SSC) which was led by Professor Mike Watson at Leicester from 1996 to 2013. An international collaboration of 10 European institutes, the SSC’s main responsibilities were the creation of the science analysis software, the processing of the science data and the compilation of sky catalogues based on the EPIC X-ray images. The work of the SSC continues with leadership now transferred to Natalie Webb in Toulouse.

Professor Mike Watson, leader of the SSC for 18 years, said: “I am very pleased that the whole SSC team, through its expertise and dedicated efforts, has been able to enhance XMM-Newton’s great success. The SSC’s sophisticated software to analyse the data and its high quality data processing have been key to ensuring the best science can be performed by the mission. It’s great to see XMM-Newton reach its 20th anniversary!”

Additionally, Leicester’s Professor Richard Willingale was a member of the XMM Telescope Working Group of X-ray optics experts. This group was responsible for the design of the optics, oversight of the manufacture of the optics and definition of the calibration of the optics both on the ground and in-flight. As part of Professor Willingale's involvement he set up a full computer simulation model of the optics using ray tracing which was used for performance prediction and calibration analysis.

XMM Newton was launched at 14:32 GMT on 10 December 1999 aboard an Ariane 5 rocket blasting off from the ESA spaceport in French Guiana. Since then it has:

• Completed more than 3,500 orbits of the Earth
• Been used by more than 5,000 researchers internationally
• Studied more than half a million X-ray sources
• Resulted in more than 6,000 published papers.

Professor Paul O’Brien said: “XMM-Newton has greatly exceeded our expectations. The observations have revealed how the force of gravity, first quantified by Sir Isaac Newton, works under the most extreme conditions in the universe. We’ve seen matter torn apart to power giant outflows, spinning massive black holes and emission from exploding stars. I look forward to more amazing discoveries in the future.”

Dr Sarah Casewell, STFC Ernest Rutherford Fellow, said: “Every day students and staff in the School of Physics and Astronomy walk past models of the XMM mirrors and EPIC camera in the building’s foyer. Whether studying how X-ray mirrors work in lectures taught by the people that designed and built the instrumentation, or learning about the astrophysics XMM is observing, or using real XMM data in undergraduate research projects, XMM and our involvement with it, has been part of the student experience at Leicester for 20 years now.”

Scientists at the University of Leicester will join with colleagues around the world on Tuesday to celebrate the anniversary on Twitter with personal memories of the mission and its research, using the hashtag #XMM20.