Powerful Gamma Rays from a Remote Galaxy Detected
It happened in April 2015. A flood of powerful gamma rays crashed into our very own atmosphere.
Where did they come from? Scientists are trying to find out from the information they have captured through the Very Energetic Radiation Imaging Telescope Array System (VERITAS).
Now these gamma rays are "photons of light with very high energies" and their source is a galaxy called PKS 1441+25, a rare type called a "blazar".
The centre of this galaxy is a supermassive black hole surrounded by a circle of hot gas and dust, according to scienceworldreport.
There is some material from the disk that keeps swirling toward the supermassive black hole. Some of it divides into twin jets blasting outward, which travels almost close to the speed of light. One of them gets aimed near the earth's direction, giving us an insight into the core of the galaxy.
"We're looking down the barrel of this relativistic jet," said Wystan Benbow, one of the researchers, in a news release. "That's why we're able to see the gamma rays at all."
The exact location of gamma-ray emissions is not known in blazar physics. With information sourced from VERITAS and the Fermi Gamma-Ray Space Telescope, researchers found that the gamma rays are actually far away from the black hole.
Moreover, the source of the gamma rays seemed bigger than is visible in an active galaxy.
"These jets have clumps in them," said Matteo Cerruti, co-author of the study. "It's possible that two of those clumps may have collided and that's what generated the burst of energy."
The findings are published in the Astrophysical Journal Letters.