Fast Radio Burst

Why in the News?

Astronomers have detected a mysterious, repeating fast radio burst emanating from a dwarf galaxy located 3 billion light-years away.

FRBs are high-energy phenomena, emitting electromagnetic energy in the form of bursts of radio pulses
These last for an interval ranging from a mere fraction of a millisecond to a few milliseconds
In each pulse, the source can emit as much energy as the sun does in a month
FRBs are triggered by explosive events in the universe, such as a supernova or the collision of two compact objects like a neutron star and a black hole
Such bursts typically occur as a transient flash only once, never to be seen again
FRBs were first discovered in 2007 and there are still many gaps in information regarding them

Many theories have suggested that FRBs are caused by neutron stars, that are the corpses of stars which died in explosions called supernovas
The latest studies, published in a recent edition of the journal Nature have now confirmed that FRBs are in fact generated by a rare type of neutron star known as a ‘magnetar’
A defining property of these bursts is their dispersion:
- The bursts produce a spectrum of radio waves, and as the waves travel through matter, they spread out – or disperse – with bursts at higher radio frequencies arriving at telescopes earlier than those at lower frequencies

A magnetar is a rare compact type of neutron star
They are highly dense and have high rotation speeds i.e. 0.3 to 12.0 seconds
Magnetars are formed when massive stars with masses around 10-25 times the mass of the Sun – collapse and shrink to form very compact objects called neutron stars

A subset of these neutron stars are called magnetars which possess intense magnetic fields

Magnetars have high magnetic fields in the range of 1015 gauss and they emit energy in the range given by luminosities of 1037– 1040 joules per second
They emit violent flares which not only help us understand the physics of magnetars but are also helpful in understanding fast radio bursts

FRBs are most likely bright analogs of pulsars, which are spinning neutron stars with strong magnetic fields
The duration and radio frequency of FRBs is similar to the flashes from pulsars, but they are intrinsically billions times brighter
As a result, we can see them from the edge of the Universe. Pulsars, on the other hand, are detectable only within the Milky Way galaxy

The unique properties of fast radio bursts and their host galaxies – combined with recent technological advancements like the CHIME telescope – have given researchers hope that these phenomena can be used to answer some long-standing questions about the universe