Most energetic form of light-bursts in space has two forms

Artist's rendition of Gamma Ray Burst (Image credit:  ESO/A. Roquette)
Artist’s rendition of Gamma Ray Burst (Image credit: ESO/A. Roquette)

Main Points:

Scientists have found a new type of gamma-ray burst (GRB) called radio faint GRB that is unlike usual GRBs due to differences in the magnetic field of the exploding star.

Published in:

The Astrophysical Journal

Study Further:

Gamma-ray burst (GRB):

GRBs are bright flashes of gamma rays – the most energetic form of light – that are found with the explosions of huge stars in remote galaxies.

Present Study:

Astronomers thought that all GRBs are followed by a strong radio afterglow but the present study changed the concept.

“We were wrong. After studying an ultra-sensitive image of GRBs with no afterglow, we can now say the theory was incorrect and our telescopes have not failed us,” said Dr Paul Hancock of Curtin University, who is the lead author of the paper. “In our research paper we argue that there must be two distinct types of GRBs, likely linked to differences in the magnetic field of the exploding star.”

Scientists noted these two different GRBs as “radio bright and radio faint”.

Scientists have found that huge exploding stars linked to the newly found type of GRBs “switch off” their radio transmissions before failing into a black hole. One last strong beam of GRBs is emitted utilizing all of the energy of the stars before they come to an end. Scientists have noted that less than 70% of GRB afterglows are radio bright while the remaining are radio faint.

“GRBs are thought to mark the birth of a black hole or neutron star – both of which have super-dense cores. But neutron stars have such strong magnetic fields that producing gamma-rays are more difficult. We think that those stars that collapse to form a neutron star have energy left over to produce the radio afterglow whereas those that become black holes put all their energy into one final powerful gamma-ray flash,” Dr Hancock said.

“We now have to take a whole new look at gamma-ray bursts – so far this work has shown that being wrong is sometimes more interesting than being right,” Dr Hancock said.

Sources:

Gamma-Ray Bursts: Introduction to a Mystery – NASA (http://goo.gl/gQ7KXq)

Astronomers Discover New Kind of Gamma-Ray Burst – Sci-news (http://goo.gl/x2T0JX)

Paul J Hancock, Bryan M Gaensler, & Tara Murphy (2013). Two populations of gamma-ray burst radio afterglows arXiv arXiv: 1308.4766v2

Usman Zafar Paracha

Usman Zafar Paracha is a sort of entrepreneur. He is the author of "Color Atlas of Statistics", and the owner of an Android game "Faily Rocket."