Black Hole GRS 1915+105

Source: NIE

Context: ISRO-led scientists observed rapid X-ray flickers from black hole GRS 1915+105 and published findings in Monthly Notices of the Royal Astronomical Society.

• AstroSat data revealed oscillating plasma corona linked to high-frequency Quasi-periodic Oscillations (QPOs).

About Black Hole GRS 1915+105:

• What is GRS 1915+105? It is a stellar-mass black hole located in a binary system, paired with a normal star, and known for highly variable X-ray emissions.

• It is a stellar-mass black hole located in a binary system, paired with a normal star, and known for highly variable X-ray emissions.

• Discovered By: Detected in 1992 by the WATCH all-sky monitor on the Granat

• Located In: Approximately 28,000 light-years from Earth in the constellation Aquila, within the Milky Way galaxy.

• Key Features:

• Mass: ~12 times that of the Sun. High Variability: Shows alternating X-ray dips and flares every few hundred seconds. High Frequency QPOs Detected: Rapid flickers at 70 Hz (Quasi-periodic Oscillations) during bright phases. Plasma Corona: Oscillates between compact-hot and expanded-cool states, driving X-ray variability. Accretion Process: Sucks in material from companion star forming a swirling accretion disk (1–10 million °C) and ultra-hot corona (~100 million °C).

• Mass: ~12 times that of the Sun.

• High Variability: Shows alternating X-ray dips and flares every few hundred seconds.

• High Frequency QPOs Detected: Rapid flickers at 70 Hz (Quasi-periodic Oscillations) during bright phases.

• Plasma Corona: Oscillates between compact-hot and expanded-cool states, driving X-ray variability.

• Accretion Process: Sucks in material from companion star forming a swirling accretion disk (1–10 million °C) and ultra-hot corona (~100 million °C).

• Significance:

• AstroSat Breakthrough: First Indian observatory to capture dynamic corona behaviour in real time. Theoretical Advancement: Supports the idea that high-frequency X-ray flickers originate from compact corona around black holes. Astrophysics Insight: Helps decode the physical environment near event horizons where gravity is extreme.

• AstroSat Breakthrough: First Indian observatory to capture dynamic corona behaviour in real time.

• Theoretical Advancement: Supports the idea that high-frequency X-ray flickers originate from compact corona around black holes.

• Astrophysics Insight: Helps decode the physical environment near event horizons where gravity is extreme.