Hummingbird News Desk
GUWAHATI, 16 NOV: In a historic breakthrough, researchers from the Indian Institute of Technology Guwahati (IIT Guwahati) and the U. R. Rao Satellite Centre, Indian Space Research Organisation (ISRO), Bengaluru, have successfully detected polarized emissions from a black hole source beyond our Milky Way Galaxy. This remarkable achievement was made possible through the implementation of X-ray polarimetry, a cutting-edge observational technique.
The focus of their study was the Large Magellanic Cloud X-3 (LMC X-3), a binary star system composed of a black hole and a ‘normal’ star significantly larger and hotter than the Sun. Situated in a satellite galaxy of the Milky Way, nearly 200,000 light-years away from Earth, LMC X-3 has been under observation since its discovery in 1971. However, until now, there has been a critical gap in understanding the polarization properties of X-rays emitted by highly energetic objects such as stellar mass black holes in the universe.
Professor Santabrata Das from the Department of Physics at IIT Guwahati emphasized the unique significance of X-ray polarimetry, stating, “LMC X-3 emits X-rays that are 10,000 times more powerful than those from the Sun. When these X-rays interact with the material around black holes, specifically when they scatter, it changes the polarization characteristics, i.e., degree and angle. This helps in understanding how matter is drawn toward black holes in the presence of intense gravitational forces.”
The researchers utilized The Imaging X-ray Polarimetry Explorer (IXPE), NASA’s first mission dedicated to studying the polarization of X-rays from celestial objects, to study LMC X-3. Simultaneously, they leveraged the broad-band coverage of the Neutron Star Interior Composition Explorer (NICER) Mission and the Nuclear Spectroscopic Telescope Array (NuSTAR) Mission to constrain the spin of LMC X-3.
Dr. Anuj Nandi, a scientist at the U. R. Rao Satellite Centre (URSC), ISRO, Bangalore, commented on this groundbreaking finding, stating, “Intense gravitational fields can cause the emitted light from black holes to become polarized. Our observations indicate that LMC X-3 likely harbors a black hole with a low rotation rate, surrounded by a slim disc structure that gives rise to the polarized emissions.”
This pioneering research not only deepens our understanding of the mysterious behavior of black holes but also showcases the capabilities of Indian scientists and their collaboration with international space agencies in advancing our knowledge of the cosmos. The findings open new avenues for exploring the dynamics of black hole environments and the role of polarization in deciphering their intricate nature.
