ISRO is set to welcome the new year with the launch of its first X-Ray Polarimeter Satellite that would offer insights into celestial objects like black holes, onboard a Polar Satellite Launch Vehicle rocket on Monday. The launch comes after the success of its Gaganyaan Test Vehicle D1 mission in October.
The PSLV-C58 rocket, in its 60th mission, would carry primary payload XPoSat and 10 other satellites to be deployed in low earth orbits. The 25-hour countdown commenced on Sunday for the lift-off scheduled at 9.10 am from the first launch pad at this spaceport, located about 135 kms east of Chennai, on January 1.
“The countdown commenced for PSLV-C58 at 8.10 am today,” ISRO sources said. The X-ray Polarimeter Satellite (XPoSat) is aimed to investigate the polarisation of intense X-ray sources in space. According to ISRO, it is the first dedicated scientific satellite from ISRO to carry out research in space-based polarisation measurements of X-ray emission from celestial sources. Besides ISRO, the US-based National Aeronautics Space Agency (NASA) conducted a similar study — the Imaging X-Ray Polarimetry Explorer mission in December 2021 on the remnants of supernova explosions, the particle streams emitted by black holes and other cosmic events.
While space-based X-ray astronomy has been established in India focusing on imaging, and time domain studies, Monday’s mission marks a major value-addition to the scientific fraternity, the space agency said.
The objective of the PSLV-C58 mission includes measuring polarisation of X-rays in the energy band 8-30 keV emanating from about 50 potential cosmic sources, to carry out long term spectral and temporal studies of cosmic x-ray sources.
The X-Ray polarisation serves as a crucial diagnostic tool for examining the radiation mechanism and geometry of celestial sources.
The primary payload of XPoSat is POLIX (Polarimeter Instrument in X-Rays) which is designed to measure polarimetry parameters by Raman Research Institute and XSPECT (X-ray Spectroscopy and Timing) built by the U R Rao Satellite Centre, Bengaluru. The Mission life is about 5 years.
The space-based study of X-Ray polarisation is gaining utmost importance internationally, and in this context, the XPoSat mission would play a significant role, ISRO added. XPoSat is anticipated to bring substantial benefits to the Astronomy community globally.
Apart from its capability of timing and spectroscopy-based observations, the insights derived from X-ray polarisation measurements on celestial objects like black holes, neutron stars, and active galactic nuclei, hold the potential to significantly improve the understanding of their physics.
