The eXTP Mission

The enhanced X-ray Timing and Polarimetry mission (eXTP) is a science mission designed to study the state of matter under extreme conditions of density, gravity and magnetism. Primary goals are the determination of the equation of state of matter at supra-nuclear density, the measurement of QED effects in highly magnetized star, and the study of accretion in the strong-field regime of gravity. Primary targets include isolated and binary neutron stars, strong magnetic field systems like magnetars, and stellar-mass and supermassive black holes.

The mission carries a unique and unprecedented suite of state-of-the-art scientific instruments enabling for the first time ever the simultaneous spectral-timing-polarimetry studies of cosmic sources in the energy range from 0.5-30 keV (and beyond). Key elements of the payload are:

  • the Spectroscopic Focusing Array (SFA): a set of 11 X-ray optics operating in the 0.5-10 keV energy band with a field-of-view (FoV) of 12 arcmin each and a total effective area of ∼0.9 m2 and 0.6 m2 at 2 keV and 6 keV respectively. The telescopes are equipped with Silicon Drift Detectors offering <180 eV spectral resolution.
  • the Large Area Detector (LAD): a deployable set of 640 Silicon Drift Detectors, achieving a total effective area of ∼3.4 m2 between 6 and 10 keV. The operational energy range is 2-30 keV and the achievable spectral resolution better than 250 eV. This is a non-imaging instrument, with the FoV limited to <1° FWHM by the usage of compact capillary plates. 
  • the Polarimetry Focusing Array (PFA): a set of 2 X-ray telescope, achieving a total effective area of 250 cm2 at 2 keV, equipped with imaging gas pixel photoelectric polarimeters. The FoV of each telescope is 12 arcmin and the operating energy range is 2-10 keV.
  • the Wide Field Monitor (WFM): a set of 3 coded mask wide field units, equipped with position-sensitive Silicon Drift Detectors, covering in total a FoV of 3.7 sr and operating in the energy range 2-50 keV.

The eXTP international consortium includes major institutions of the Chinese Academy of Sciences and Universities in China, as well as major institutions in several European countries and other Internatinal partners.

eXTP is an enhanced mission concept based on the XTP mission, enabled by the collaboration between Chinese and European institutions. The predecessor of eXTP, the XTP mission concept, has been selected and funded as one of the so-called background missions in the Strategic Priority Space Science Program of the Chinese Academy of Sciences since 2011. The strong European participation has significantly enhanced the scientific capabilities of eXTP. The planned launch date of the mission is earlier than 2025.

Sketch of the eXTP satellite. Closer view of the different eXTP payload elements.