Why in the news?
Astronomers from the Indian Institute of Astrophysics have traced the likely origin of a rare Fast X-ray Transient (FXT) event, EP241107a, detected by the Einstein Probe in November 2024.
Key Findings
- FXTs are energetic, non-repeating flashes of X-rays lasting from a few minutes to several hours.
- They are a recently discovered class of transient cosmic events whose origin has remained uncertain.
- Researchers identified a radio counterpart of FXT EP241107a using the Karl G. Jansky Very Large Array.
- Follow-up observations were conducted using:
- Himalayan Chandra Telescope
- GROWTH India Telescope
- Upgraded Giant Metrewave Radio Telescope
Likely Origin
- The event was probably caused by: Collapse of a massive star leading to a supernova and gamma-ray burst (GRB), or Merger of two neutron stars.
- Researchers concluded that EP241107a is most likely an “orphan afterglow”:
- A gamma-ray-burst-like explosion whose gamma rays were not directly detected.
- Represents a lower-energy member of the GRB population.
Fast X-ray Transients (FXTs)
- Sudden flashes of low-energy X-rays.
- Non-repeating and short-lived.
- Fade rapidly after detection.
- Associated with highly energetic cosmic explosions.
Proposed Sources
- Core-collapse supernovae.
- Binary neutron star mergers.
- Magnetars (highly magnetized neutron stars).
- Tidal disruption events involving white dwarfs and black holes.
- Gamma-ray bursts (GRBs).
Gamma-Ray Bursts (GRBs)
- Most energetic explosions known in the Universe.
- Emit intense gamma radiation for a few milliseconds to several minutes.
- Associated with the collapse of massive stars (Long GRBs) and Neutron star mergers (Short GRBs).
- Followed by multi-wavelength “afterglows” in X-ray, optical, and radio bands.
Neutron Star
- Extremely dense remnant of a massive star after a supernova.
- Mass ≈ 1.4-2 solar masses compressed into a sphere about 20 km across.
- Composed mainly of neutrons.
[2023] 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
How many of the above pairs are correctly matched ?
[A] Only one
[B] Only two
[C] All three
[D] None