IXPE

Three identical Wolter-Igrazing-incidence opticsX-rays reflect only at angles of a degree or less, so X-ray telescopes use nested shells of paraboloid and hyperboloid mirrors seen almost edge-on (the Wolter-I design). More shells add effective area; figure accuracy sets the PSF. telescopes with gas pixel detectors that track each photoelectron, measuring the polarisationpolarimetryMeasuring the polarisation of incoming radiation. It encodes magnetic-field geometry, scattering and emission mechanisms; in the CMB it separates E- and B-mode patterns. degree and angle of 2–8 keVelectronvoltThe energy an electron gains across 1 volt, 1.602 × 10⁻¹⁹ J. High-energy astronomy labels photons by energy: optical light is about 1.7–3.1 eV, X-rays 0.1–100 keV, gamma rays from about 100 keV to beyond 100 TeV. A 1 keV photon has wavelength 1.24 nm. X-rays while imaging at about 30″. Polarimetry constrains the geometry of coronae around accreting black holes, magnetic fields in pulsarpulsarA rotating, magnetised neutron star whose beamed emission sweeps past Earth once per turn. Millisecond pulsars, spun up by accretion, keep time to tens of nanoseconds over decades. wind nebulae and blazar jets, and the emission physics of magnetars. NASA with ASI.

Operator

NASA, ASI

Orbit

Low Earth orbit

Passband

2 keV – 8 keV

Launch

9 December 2021