Fast Radio Bursts (FRBs)
Fast Radio Bursts are enigmatic flashes of radio waves coming from deep space and last just milliseconds.
Some Key Characteristics
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Duration: Generally, FRBs tend to last just a few milliseconds.
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Energy: Although less energetic than in the case of GRBs, FRBs still release a huge amount of energy in the form of radio waves.
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Wavelength: FRBs radiate mainly in the radio part of the electromagnetic spectrum.
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Dispersion: The radio signal from FRBs gets dispersed due to free electrons present in space. Higher frequencies reach earth before lower ones.
Origins
The exact cause of FRBs remains one of the biggest mysteries in modern astronomy. Some possible explanations that have been suggested include:
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Magnetars: Highly magnetized neutron stars undergoing “starquakes” or magnetic reconnection events. The detection, in 2020, of an FRB-like signal from a Galactic magnetar supports this hypothesis to some extent.
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Neutron star mergers: Similar to that for short GRBs, but possibly viewed from a different angle.
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Pulsar phenomena: Some models interpret FRBs as giant pulses from young, highly magnetized pulsars.
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Alien signals: Some suspect artificial origins, however, this is now considered extremely improbable.
Primarily, FRBs are detected via radio telescopes like CHIME and ASKAP. The issue with exploring FRBs is that they are very quick, and identifying where they originate from is challenging.
FRBs are valuable tools for the study of the intergalactic medium because radio waves are dispersed by free electrons when they propagate in space. This can be measured, so it helps astronomers to have an estimate of the matter located between Earth and the origin of the FRB.
The FRBs are far more frequent than GRBs. It is possible that thousands of FRBs may be observed all over the sky every day, whereas only a few GRBs can be usually detected daily.