15 C
Tuesday, September 26, 2023
HomeSciencePossible rewritten title: Solving the Mystery of the Most Persistent Cosmic Explosion...

Possible rewritten title: Solving the Mystery of the Most Persistent Cosmic Explosion Ever Recorded


The X-rays of the brightest gamma-ray burst ever recorded were reflected off layers of dust, creating extended “light echoes” of the initial blast. Credit: NASA

Firstly was detected by mistake By US military satellites in the late 1960s, cosmic explosions known as gamma ray bursts (GRBs) came to be understood as the brightest explosions in the universe.

Usually, they are is the score From the cataclysmic birth of a black hole in a galaxy far, far away. One way this could happen is through the collapse of one massive star.

Astronomers like myself who work in this field are well aware of the enormous energy scales involved in GRBs. We know that they can release as much energy in gamma rays as the Sun does throughout its life. But every now and then, an event is noticed that still gives us pause.

In October 2022, gamma-ray detectors on the orbiting Fermi satellites and the Neil Gehrels Swift Observatory Notice an explosion Known as GRB 221009A (Date of Detection).

This quickly turned into a record. It has been dubbed “the brightest of all time,” or “the boat,” as an apt shorthand among astronomers who study and observe the event. Not only did the boat start out with a bright light, it refused to fade like other bursts of light.

We still don’t quite know why the explosion was so bright, but our new study, Posted in Science advancesprovides an answer to her obstinate persistence.

The burst originated from 2.4 billion light-years away – relatively close to the GRB. But even when accounting for the relative distance, the energy of the event and the radiation from its aftermath were off the charts. It is certainly anomalous for a distant cosmic event to deposit about a gigawatt of energy into Earth’s upper atmosphere.

Observation of cosmic narrow gas jets

GRBs like a boat release a stream of gas that moves very close to the speed of light through space. How exactly the jet is launched remains a mystery — but most likely, it involves magnetic fields near where the black hole formed.

It is the early emission from this jet that we see as an explosion. Later, the jet slows and emits additional radiation, a faint glow of light – from radio waves to (in exceptional cases) gamma rays.

We do not notice the planes directly. Instead, like distant stars, we see GRBs as points in the sky. However, we have good reason to believe that gas bombs do not explode equally in all directions. For GRB 221009A, this would certainly be a no-brainer, because it would involve doubling the amount of energy detected on Earth in all other directions—which amounts to far more energy than would ever be available to any star.

Another indication that GRBs come from jets directed almost at us is due to the theory of special relativity. Relativity teaches us that the speed of light is constant, no matter how fast the source is moving at us. But this still allows distortion of the direction of the light. With this playful mirror effect, the light emitted in all directions from the surface of a fast-moving jet plane will end up focusing strongly on its direction of motion.

However, the edges of an aircraft heading in our direction will be curved very slightly, which means that its light is focused away from us. Only later, as the aircraft slows down, do edges appear more naturally and afterglow begins to fade faster.

But here again, GRB 221009A has broken the rules. Her edges are never shown, and she’s joined a selection of very bright bangs that refuse to fade naturally. Instead of starting to fade slowly and then disappearing quickly, it fades steadily over time.

In our work, we show how the appearance of jet edges can be masked in a way that matches the boat’s observations. The main idea is as follows: Yes, a narrow jet was launched, but it had difficulty escaping the collapsing star, resulting in a lot of interstellar gas mixing along the sides of the jet.

From simulation to observation

To test whether this is indeed the case, we took result of computer simulation Display and implement this mixing in a form that can actually be compared directly with the boat data. And it showed that what would normally be a quick turn into a severely faded signal is now a stretch.

Radiation from the shock-heated gas of the dying star kept flashing in our field of view, explaining why it remained so bright. This continued to occur to the point where any distinct jet signature was lost in the overall emission.

In this way, GRB 221009A not only confirms predictions from simulations, but also provides evidence of similar bright events seen in the past that people had to keep. Revise energy rating up while waiting for a plane to appear.

We calculated that the odds of seeing an explosion this bright is about one in a thousand years, so we’re lucky to have detected one. But questions remain. What role do magnetic fields play, for example?

Theorists and numerical modelers will be exploring these for years, poring over the boat data as we stay on the lookout for the next big event to arrive.

Introduction to the conversation

This article has been republished from Conversation Under Creative Commons Licence. Read the The original article.Conversation

the quote: The Brightest Cosmic Explosion Ever: How We Can Solve the Mystery of Its Perplexing Continuation (2023, June 10) Retrieved June 10, 2023 from https://phys.org/news/2023-06-brightest-cosmic-explosion-mystery-puzzling. html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without written permission. The content is provided for informational purposes only.

The author of what'snew2day.com is dedicated to keeping you up-to-date on the latest news and information.

Latest stories