What Are Black Holes That ISRO's New Satellite Will Study?

The ISRO on Monday successfully launched its maiden X-Ray Polarimeter Satellite that would offer several insights into celestial objects like black holes.

"On January 1, 2024, yet another successful mission of PSLV has been accomplished. PSLV-C58 has placed the primary satellite - XPoSat - in the intended orbit of 650 km with 6-degree inclination," ISRO chief S Somanath said after the launch.

ISRO's Polar Satellite Launch Vehicle (PSLV) in its C58 mission, placed the primary X-Ray Polarimeter satellite XPoSat into a 650 Km Low Earth Orbit as intended after lifting off at the pre-fixed time of 9.10 am from the first launch pad here.

ISRO's maiden X-Ray Polarimeter Satellite would offer insights into celestial objects like black holes. So, what is black holes?

A black hole is a celestial entity characterized by an incredibly powerful gravitational force, preventing anything, including light, from escaping it. The event horizon, or the black hole's "surface," marks the boundary where the required velocity for escape surpasses the speed of light-the cosmic speed limit. Despite the attraction, matter and radiation can enter a black hole, but once inside, they cannot escape.

There are two primary categories of black holes that have been extensively observed. Stellar-mass black holes, ranging from three to dozens of times the Sun's mass, are distributed across our Milky Way galaxy. In contrast, supermassive behemoths, weighing between 100,000 and billions of solar masses, are located at the cores of most large galaxies, including our own.

"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 and thus is an excellent diagnostic tool to understand the emission processes from astronomical sources. The polarimetric observations along with spectroscopic measurements are expected to break the degeneracy of various theoretical models of astronomical emission processes. This would be the major direction of research from XPoSat by Indian science community," the ISRO said in a statement.

It is the first dedicated scientific satellite from the space agency to carry out research in space-based polarisation measurements of X-ray emission from celestial sources, the ISRO said.

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 five years, PTI reported.