Fast Radio Bursts

In News

• Recently, for the first time, astronomers of the National Centre of Radio Astrophysics (NCRA-TIFR) in Pune and the University of California in the U.S. have used the Giant Metrewave Radio Telescope (GMRT) to map the distribution of atomic hydrogen gas from the host galaxy of a fast radio burst (FRB).

Fast Radio Burst (FRB)

• They are super intense, millisecond-long bursts of radio waves produced by unidentified sources in the distant cosmos. 
• They were first discovered in 2007 when scientists combed through archival pulsar data. 
  • Pulsars refer to spherical, compact objects in the universe, which are about the size of a large city but contain more mass than the sun. 
    • They often look like flickering stars but are not stars.
• FRBs are extremely bright radio pulses from distant galaxies that last for only a few milliseconds.
• One of the best-known fast radio bursts is FRB20180916B. This FRB was discovered in 2018 and is only 500 million light-years away from us in another galaxy.
• The FRB is the closest so far and has a burst pattern that repeats every 16 days: four days of bursts, 12 days of relative quiet. That predictability makes it an ideal object for researchers to study.

About the Study

• The GMRT study indicates that the FRB host galaxy has undergone a recent merger and that the FRB progenitor is most likely a massive star formed due to the merger event. 
• This is the first case of direct evidence for a recent merger in an FRB host, a major step towards understanding the progenitors of FRBs.
• The atomic hydrogen gas contained by the host galaxy was found to be ten times more than the nearby galaxies. But despite such large atomic hydrogen gas, the number of stars were relatively fewer. It thus indicates that the surplus hydrogen gas was recently acquired after a possible merger between two galaxies.

What is the Giant Metrewave Radio Telescope (GMRT)?

• It is an array of thirty fully steerable parabolic radio telescopes of 45 meter diameter. It is operated by the National Center for Radio Astrophysics of the Tata Institute of Fundamental Research (NCRA-TIFR).
• GMRT is an indigenous project. Its design is based on the `SMART’ concept – for Stretch Mesh Attached to Rope Trusses.
• It functions at the meter wavelength part of the radio spectrum because man-made radio interference is considerably lower in this part of the spectrum in India and there are many outstanding astrophysics problems which are best studied at metre wavelengths.

Source: TH