Indian scientists have successfully detected and studied an Intermediate-Mass Black Hole (IMBH) located in the faint galaxy NGC 4395, about 4.3 million light-years away.

Key Highlights of Discovery

• The discovery was made by Aryabhatta Research Institute of Observational Sciences (ARIES), an autonomous institute of the Department of Science and Technology (DST).
• Features of the Black Hole
• • The intermediate-mass black hole (IMBH) discovered has a mass of approximately 22,000 times that of the Sun, making it one of the most precisely measured IMBHs.
  • Gas clouds were found orbiting the IMBH at a distance of 125 light-minutes (2.25 billion km) with a velocity dispersion of 545 km/s.
  • The black hole is accreting matter at just 6% of its theoretical maximum rate, indicating a faint but active galactic nucleus.
• Instruments Used: Observations were conducted using the 3.6-metre Devasthal Optical Telescope (DOT) and the 1.3-metre Devasthal Fast Optical Telescope (DFOT), equipped with the Aryabhatta Devasthal Faint Object Spectrograph and Camera (ADFOSC), an indigenously developed system for photometry and spectroscopy.
• Technique Applied: The team employed spectrophotometric reverberation mapping to calculate the time delay between emissions, helping determine the black hole’s mass.

What are IMBHs?

• Intermediate-Mass Black Holes are black holes that lie between stellar-mass black holes (a few solar masses) and supermassive black holes (millions to billions of solar masses).
• IMBHs are expected to have masses ranging from 100 to 100,000 times the mass of the Sun.

Why IMBHs are Difficult to Observe

• IMBHs are often found in faint, low-luminosity galaxies, making them hard to detect.
• Unlike supermassive black holes, IMBHs typically do not emit bright radiation unless they are actively accreting matter, which further complicates their observation.

Significance of Studying IMBHs

• IMBHs are believed to be the seeds of supermassive black holes, playing a crucial role in the evolution of galaxies and black hole formation.
• Finding and measuring more IMBHs is vital for filling the missing link in the black hole mass spectrum and for understanding how massive black holes grow over cosmic time.

DOWNLOAD PDF