The Indian Space Research Organisation (ISRO) has recently embarked on a pioneering mission, launching its first X-ray Polarimeter Satellite (XpoSat) to investigate X-ray polarisation and its cosmic origins, such as Black Holes, Neutron stars, and Magnetars. Positioned in Low Earth Orbit by the PSLV-C58 rocket, XpoSat represents a significant stride for Indian astronomy and space research. This article will explore the purpose, development, and implications of this groundbreaking satellite, as well as delve into the X-ray science that powers it.
Understanding XpoSat: An Exploration in X-ray Polarisation
Designed to examine X-ray polarisation in the medium X-ray band, XpoSat is set to shine a light on the radiation mechanisms and geometry of celestial bodies. This research is key to understanding the physics operating behind these cosmic entities.
The satellite has been outfitted with two main payloads: the POLIX (Polarimeter Instrument in X-rays) and the XSPECT (X-ray Spectroscopy and Timing). POLIX will observe approximately 40 bright astronomical sources, while XSPECT will study the electromagnetic spectrum produced by different types of matter.
The Journey of XpoSat’s Development
Constructed entirely by two Bengaluru-based institutes, ISRO’s UR Rao Satellite Centre and Raman Research Institute, the development journey of XpoSat began in earnest in 2008. The culmination of this process was in 2015 when a formal agreement was inked with ISRO.
XpoSat in Global Context
While it’s not the first of its kind, XPoSat still stands as a momentous achievement. It is only the world’s second mission solely dedicated to X-ray polarization in the medium X-ray band, following NASA’s Imaging X-ray Polarimetry Explorer (IXPE), which launched in 2021.
XpoSat: A National Contribution to Space Research
XpoSat represents the third space-based observatory for India, following the recently launched solar mission Aditya-L1 and AstroSat, which was launched in 2015. This is an important milestone and progress for Indian astronomy and space research.
Understanding X-rays and Their Role in Studying Celestial Objects
X-rays refer to a type of electromagnetic radiation with wavelengths within 0.01-10 nanometres. Characterised by an electric field and a magnetic field vibrating perpendicularly to one another, the polarisation of electromagnetic radiation appears as the orientation of these two fields moves through space.
X-rays can become polarised when they are scattered. Fast-moving charged particles bent by a magnetic field also produce polarised X-rays. Employing instruments like POLIX to measure the polarisation of X-rays enables astronomers to comprehend the orientation and power of magnetic fields in celestial bodies. This capability provides key insights into the nature and behaviour of pulsars, regions around black holes, and other cosmic phenomena emitting X-rays.
