X-ray Polarimeter Satellite: ISRO

• 02 Jan 2024

Source: IE

Why in News?

Recently, the Indian Space Research Organisation (ISRO) has launched its first X-ray Polarimeter Satellite (XpoSat) to study X-ray polarisation and its cosmic sources, like Black holes, Neutron stars, and Magnetars.

• The mission is propelled by the PSLV-C58 rocket in Low Earth Orbit.

What is an X-ray Polarimeter Satellite (XpoSat)?

• Purpose:
  • XPoSat is designed to study X-ray polarization in the medium X-ray band, offering insights into celestial sources' radiation mechanisms and geometry.
  • This study is crucial for understanding the physics behind these celestial bodies.
• Payloads:
  • The satellite carries two main payloads, POLIX (Polarimeter Instrument in X-rays) and XSPECT (X-ray Spectroscopy and Timing).
  • POLIX will observe about 40 bright astronomical sources, while XSPECT will study the electromagnetic spectrum generated by different matter.
• Development:
  • Entirely built by two Bengaluru-based institutes—ISRO’s UR Rao Satellite Centre and Raman Research Institute—XPoSat's development began in 2008, with a formal agreement signed with ISRO in 2015.
• Global Context:
  • XPoSat is only the world's second mission dedicated to X-ray polarization in the medium X-ray band. NASA's Imaging X-ray Polarimetry Explorer (IXPE), launched in 2021, was the first such mission by a space agency.
• National Contribution:
  • XPoSat will be India's third space-based observatory, following the recently launched solar mission Aditya-L1 and AstroSat, which was launched in 2015. Its launch is seen as a significant stride for Indian astronomy and space research.

What is X Ray and How will it Study the Celestial Objects?

• X-rays are electromagnetic radiation whose wavelength is 0.01-10 nanometres.
  • Electromagnetic radiation is characterised by an electric field and a magnetic field vibrating perpendicular to each other.
    • The polarisation of electromagnetic radiation refers to the orientation of these two fields as the radiation moves through space.
• X-rays can be polarised when they get scattered. Polarised X-rays are also produced when the path of a fast-moving charged particle is bent by a magnetic field.
• Measuring the polarization of X-rays using instruments like POLIX enables astronomers to understand the orientation and strength of magnetic fields in celestial objects. This, in turn, provides crucial insights into the nature and behavior of pulsars, regions around black holes, and other cosmic phenomena emitting X-rays.