Context
An Article in The Hindu Explained | MACE in Ladakh opens its one-of-a-kind eye to cosmic gamma rays
About MACE Telescope:
- Major Atmospheric Cherenkov Experiment
- Inauguration and Location:
- Location: Hanle, Ladakh, India, at an altitude of 4.3 km above sea level.
- Significance: World’s highest imaging Cherenkov telescope.
- Dish Size: 21-metre-wide, largest in Asia and second-largest in the world.
- Collaborating Institutions:
- Built by Bhabha Atomic Research Centre (BARC), Tata Institute of Fundamental Research (TIFR), Electronics Corporation of India Ltd. (ECIL), and Indian Institute of Astrophysics (IIA).
- Gamma Rays:
- Gamma Rays: Shortest wavelength and highest energy in the electromagnetic spectrum.
- Each photon has over 100,000 electron volts (eV). Humans cannot directly observe gamma rays as they are blocked by Earth’s atmosphere.
- Dangerous to living cells and DNA due to their high energy.
- Gamma Rays: Shortest wavelength and highest energy in the electromagnetic spectrum.
- Cherenkov Radiation:
- Cherenkov Radiation: Blue light emitted when gamma rays interact with air molecules, producing electron-positron pairs.
- Significance: Indirect way to study high-energy gamma rays from cosmic sources.
- Imaging Atmospheric Cherenkov Telescopes (IACT):
- IACT: Used to detect gamma rays by capturing Cherenkov radiation.
- MACE is an IACT designed to study gamma rays with energies above 20 billion eV.
- Light Collector:
- MACE’s light collector has 356 honeycomb-structured mirror panels. Honeycomb mirrors are lightweight, stable, and reflective.
- James Webb Space Telescope also uses this design for similar reasons.
Scientific Goals and Targets
- Gamma-Ray Study:
- MACE studies high-energy gamma rays from cosmic sources, including black holes, pulsars, blazars, and gamma-ray bursts.
- Focus on gamma rays with energies over 20 billion eV.
- Dark Matter Research:
- MACE aims to detect weakly interacting massive particles (WIMPs), hypothesized components of dark matter. WIMPs are believed to annihilate, emitting high-energy gamma rays.
- Potential detection could help confirm or refute the WIMP hypothesis for dark matter.
- Dark Matter and Cosmic Studies:
- High-energy gamma rays from large galaxy clusters, small galaxies, and galactic centres (including the Milky Way) could offer clues about dark matter.
Technological Significance
- India’s Role in Gamma-Ray Astronomy:
- India has contributed to gamma-ray astronomy for over 50 years.
- MACE marks a significant technological leap, with most subsystems designed and built in India.
- Global Impact:
- MACE is poised to contribute significantly to high-energy astrophysics and particle physics.
- The telescope plays a role in answering fundamental questions about dark matter, cosmic sources, and high-energy particles.
Key Terms
- Gamma Rays: High-energy electromagnetic waves with extremely short wavelengths, emitted by cosmic objects like pulsars, black holes, and supernovae.
- Cherenkov Radiation: Blue light emitted when charged particles travel faster than the speed of light in a medium like air, often resulting from gamma rays interacting with the atmosphere.
- Imaging Atmospheric Cherenkov Telescopes (IACT): Telescopes designed to detect Cherenkov radiation and indirectly study gamma rays by capturing the light emitted when gamma rays interact with the atmosphere.
- WIMPs (Weakly Interacting Massive Particles): Hypothetical particles proposed as constituents of dark matter, which may produce gamma rays upon annihilation.
Source: TH
Previous Year Question
Consider the following pairs:
Objects in space: Description
1. Cepheids: Giant clouds of dust and gas in space
2. Nebulae: Stars which brighten and dim periodically
3. Pulsars: Neutron stars that are formed when massive stars run out of fuel and collapse
[UPSC Civil Services Exam – 2023 Prelims]
How many of the above pairs are correctly matched?
(a) Only one
(b) Only two
(c) All three
(d) None
Answer: (d)