Roadmap to XEUS (resubmission)

XEUS addresses fundamental questions on the nature of the Universe, its large-scale structure, and the physics of extreme environments. The mission concept embodies advanced technologies for spacecraft, optics, and detectors leading to unprecedented observational capabilities at X-ray wavelengths of the electromagnetic spectrum. This 'Roadmap to XEUS' application describes a development programme that will place UK researchers and industry in a strong position to participate actively in all phases of the mission. It is being made by a consortium of university research groups from the University of Leicester, Brunel University, Birmingham University and the Mullard Space ScienceLaboratory of University College London, together with industrial partners EADS Astrium (UK), e2v Technologies (UK) and Space Cryomagnetic. The XEUS concept envisages an X-ray observatory at L2 Lagrangian Point (at about 1.5 million km from Earth), comprising separate mirror and detector spacecraft. This configuration, coupled with recent major advances in light-weight X-ray mirror design, will provide 5 sq mtrs of collecting area / 10 to 30 times more than XMM-Newton (currently the largest X-ray observatory to be launched) / feeding a set of state-of-the-art X-ray detectors and spectrometers. The resulting very high sensitivity, combined with excellent imaging and spectral capabilities, will, for the first time, bring the power of X-ray diagnostics to bear on studies of the hot, high red-shift Universe, as well as on the behaviour of matter under extreme conditions. XEUS will study the structure and evolution of the hot plasmas that pervade the Universe, e.g. the processes of hierarchical merging, shock heating and feedback, which have heated most of the baryons of the Universe to greater than 105 K by the present epoch. It will trace the growth of structure at high redshift, providing valuable constraints on cosmology. It will probe the early growth phases of super-massive black holes, implicated in the re-ionization of the Universe at z>6, and will investigate the connection between galaxy formation and the growth of super-massive black holes. Physics under extreme conditions, close to the event horizon in black holes, will also be probed, as will the equation of state of baryonic matter in neutron stars with possible links to the strong interaction and the Standard Model. The European Space Agency (ESA) Cosmic Visions exercise assigned very high priority to XEUS science. XEUS has now been proposed to the ESA Cosmic Vision programme for the first L-class launch in 2018. XEUS also has very strong international support: the Japan Aerospace Exploration Agency is a partner in the Cosmic Vision proposal and both Russia and China have expressed strong interest in taking on a significant role in XEUS. Informal discussions are also taking place with NASA, with a view to US participation. XEUS carries forward the key scientific achievements of XMM-Newton by exploiting major emerging technical advances. This application seeks funding for a programme of technology development that will place UK research teams and UK industry in a strong position in XEUS. This application encompasses four areas of activity within the UK. In X-ray optics the goal is to support a programme of design, modelling and testing of the new silicon micro-pore optics technology, which could give the UK Principal Investigator status in this core XEUS programme. Detector development programmes are proposed encompassing the extended wide-field imager and the cryogenic narrow-field instrument, both of which are key elements of the XEUS focal plane instrumentation suite. The proposal also seeks support for the continuing development of adiabatic demagnetisation refrigerators as the milli-Kelvin flight cooler for XEUS. Involvement of UK industry has been secured in all of these areas and indeed will be critically important for the success of the programme.