Searching for the first black holes

Name: XEUS stands for the X-ray Evolving Universe Spectroscopy.

Description: XEUS is a potential follow-on to ESA's highly successful XMM-Newton X-ray observatory. XEUS will consist of two spacecraft – one carrying the mirrors, the other carrying the detectors. They will fly in formation 50 metres apart. It is designed to search for the first massive black holes that formed in the Universe, over 10 thousand million years ago.

Launch: After 2015 (Ariane-5 at Kourou, French Guiana).

Status: Under assessment.

Journey: XEUS will be put into orbit at the second Earth-Sun Lagrangian point (L2).

Notes: Current plans for XEUS call for two novel imaging spectrometers working at temperatures close to absolute zero (-273°C).

XEUS will use the revolutionary new silicon micro-pore optics, developed by ESA, which will provide even finer imaging quality than XMM-Newton, for about one tenth of the weight!

XEUS will study the first massive black holes formed over 10 000 million years ago and measure their masses, luminosities and rotation periods.

Black holes grow by accreting material such as the remnants of stars that wander too close and are torn apart by the intense gravitational field. By seeing how the properties of black holes evolve with cosmic time, XEUS will track the history of their accretion.

XEUS is likely to become the first truly global X-ray astronomy mission with many nations contributing to the project.