Why in news?
Indian astronomers using data from the AstroSat satellite observed rapid X‑ray flickers from the black hole GRS 1915+105 and published their findings in an international journal. The observations provide new insights into high‑energy processes near black holes.
Key facts
- GRS 1915+105 is a stellar‑mass black hole paired with a normal star about 28,000 light‑years away in the constellation Aquila. It was discovered in 1992 and is known for highly variable X‑ray emissions.
- The black hole’s mass is roughly twelve times that of the Sun. Matter pulled from the companion star forms an extremely hot accretion disk and corona, producing X‑ray flares.
- AstroSat data revealed quasi‑periodic oscillations at about 70 hertz. Scientists observed the plasma corona switching between compact‑hot and expanded‑cool states, causing rapid flickers.
Importance
- The observations confirm that high‑frequency X‑ray variability arises from oscillations in the corona rather than the accretion disk alone, enhancing our understanding of black hole physics.
- AstroSat, India’s first dedicated space observatory, played a crucial role and showcases the country’s capability in high‑energy astrophysics.
