XPoSat: India's first dedicated X-ray polarimetry mission, carrying POLIX and XSPECT

Background

XPoSat, the X-ray Polarimeter Satellite, is India's first dedicated polarimetry mission to study the dynamics of bright astronomical X-ray sources in extreme conditions.
The spacecraft carries two scientific payloads in a low earth orbit.
The primary payload POLIX, the Polarimeter Instrument in X-rays, measures the degree and the angle of polarization in the medium X-ray energy range of 8-30 keV.
POLIX is made of a collimator, a scatterer and four X-ray proportional counter detectors surrounding the scatterer, and the collimator restricts the field of view to 3 degree x 3 degree so that only one bright source falls in the field.
The second payload XSPECT, X-ray Spectroscopy and Timing, gives spectroscopic information in the energy range of 0.8-15 keV.
The sources studied include black holes, neutron stars, active galactic nuclei, pulsar wind nebulae, X-ray pulsars and magnetars.
POLIX is expected to observe about 40 bright astronomical sources of different categories during a planned mission lifetime of about 5 years.
The satellite was flown as the PSLV-C58 mission.