India set to launch X­ray Polarimeter Satellite, says ISRO

India set to launch X­ray Polarimeter Satellite, says ISRO

Subject :Science and Tech

Section: Space tech

Context:

Indian Space Research Organisation (ISRO) has announced that India is set to launch its first X-Ray Polarimeter Satellite (XPoSat), aiming to investigate the polarisation of intense X-Ray sources.

About the mission:

• The XPoSat spacecraft is designated for observation from Low Earth Orbit, carrying two scientific payloads.
• With these two payloads, the XpoSat mission is capable of simultaneous studies of temporal, spectral, and polarization features of the bright X-Ray sources.
• The mission objectives include:
  • measurement of X-Ray polarization in the energy band of 8-30 keV emanated from X-Ray sources,
  • long-term spectral and temporal studies of cosmic X-Ray sources in the energy band of 8-15 keV.
• The mission life is expected to be approximately five years.
• The payloads onboard XpoSat will observe the X-Ray sources during the spacecraft’s transit through the Earth’s shadow, i.e., during the eclipse period.
• The XpoSat will be launched by the Polar Satellite Launch Vehicle (PSLV), from the Satish Dhawan Space Center in Sriharikota.
• XpoSat (X-ray Polarimeter Satellite) is India’s first dedicated polarimetry mission to study various dynamics of bright astronomical X-ray sources in extreme conditions.
• The spacecraft will carry two scientific payloads in a low earth orbit.
  • The primary payload POLIX (Polarimeter Instrument in X-rays) will measure the polarimetry parameters (degree and angle of polarization) in medium X-ray energy range photons of astronomical origin.
  • The XSPECT (X-ray Spectroscopy and Timing) payload will give spectroscopic information.

Significance of the mission:

• The emission mechanism from various astronomical sources such as blackhole, neutron stars, active galactic nuclei, pulsar wind nebulae etc. originates from complex physical processes and are challenging to understand.
• While the spectroscopic and timing information by various space based observatories provide a wealth of information, the exact nature of the emission from such sources still poses deeper challenges to astronomers.
• The polarimetry measurements add two more dimension to our understanding:
  • the degree of polarization and
  • the angle of polarization
• Thus is an excellent diagnostic tool to understand the emission processes from astronomical sources.