Editorial Analysis: ISRO's New X-ray Eye in the Sky

Table of Contents

Context: The launch of XPoSat Mission was the world’s second space mission to study the polarisation of cosmic X-rays, after NASA’s IXPE.

What Are X-Rays?

X-rays are formed by the movement of electric charges, which disrupts electric and magnetic fields.
Polarised X-rays: When the electric field of X-rays fluctuates in a specific direction during wave propagation, the X-rays are termed as “polarised.”
- This directionality of the electric field is influenced by the motion of the electric charges (like accelerating electrons) that generate the X-ray.
Polarisation in Stellar Objects: In astronomical bodies with strong magnetic fields, electrons orbit around magnetic fields, emitting polarised X-rays.
- This is different from most stars that emit unpolarized light.
Studying Polarised X-Rays: Analysing the polarisation of X-rays can provide insights into objects like pulsars and black hole regions.
- Pulsars, rotating neutron stars, emit two polarised radio lights with distinct timing and polarisation patterns.
Challenges in X-ray Study: Due to their high energy, X-rays can’t be focused using ordinary lenses and are mostly absorbed by the Earth’s atmosphere, making them difficult to study from Earth.

We’re now on WhatsApp. Click to Join

Approach: The mission’s primary tool, POLIX (Indian X-ray Polarimeter), is designed to analyse X-rays’ unique properties in space. It features a beryllium disc and detectors along its walls to capture X-rays. POLIX enables the study of lower energy X-rays than current NASA instruments.
XSPECT Instrument on XPoSat: This secondary instrument on XPoSat is dedicated to examining the timing and spectral attributes of X-ray emitting space objects.
ISRO’s Capability: The XPoSat mission demonstrates ISRO’s proficiency and advancement in planetary research, contributing significantly to space science.