Science & Technology
GMRT Reveals Fast Radio Bursts
- 22 Feb 2022
- 4 min read
Why in News?
Recently, the Astronomers of National Center of Radio Astrophysics (NCRA-TIFR) in Pune and the University of California in the US 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) for the first time.
What are Fast Radio Bursts?
- The first FRB was discovered in 2007, since when scientists have been working towards finding the source of their origin.
- Essentially, FRBs are bright bursts of radio waves (radio waves can be produced by astronomical objects with changing magnetic fields) whose durations lie in the millisecond-scale, because of which it is difficult to detect them and determine their position in the sky.
- These extraordinary events generate as much energy in a thousandth of a second as the Sun does in a year.
- Locating where these blasts are coming from, and in particular, what galaxies they originate from, is important in determining what kinds of astronomical events trigger such intense flashes of energy.
- 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.
What does the Study Suggest?
- The FRB (FRB20180916B) host galaxy has undergone a recent merger and that the FRB progenitor is most likely a massive star formed due to this merger event.
- 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 GMRT?
- GMRT 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.
- The location for GMRT, Pune meets several important criteria such as low man-made radio noise, availability of good communication, vicinity of industrial, educational and other infrastructure and,a geographical latitude sufficiently north of the geomagnetic equator in order to have a reasonably quiet ionosphere and yet be able to observe a good part of the southern sky as well.