Scientists May Have an Answer to the Mystery of Ghostly Gamma Ray Bursts

Tuesday, 09 October 2018 - 12:18PM
Astronomy
Space
Tuesday, 09 October 2018 - 12:18PM
Scientists May Have an Answer to the Mystery of Ghostly Gamma Ray Bursts
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NASA/Swift/Mary Pat Hrybyk-Keith and John Jones
For years, astronomers have struggled to find what exactly is causing the mysterious phenomenon known as "fast radio bursts:" the extremely powerful radio waves that last for less than a second. At the same time, they've been searching for the cosmic objects responsible for "orphan" gamma ray bursts, whose sources have seemingly disappeared. Now it seems the answers to both mysteries may be the same—magnetars.

Magnetars are neutron stars with extremely strong magnetic fields that emit lighthouse-like beams of matter and energy, similar to a pulsar. In time, a magnetar may devolve into a pulsar and seemingly disappear from equipment meant to detect gamma rays, but before then it has some unique properties—and if new research from the University of California, Berkeley is correct, one of those properties is creating strong gamma ray bursts. What's interesting is that astronomers may have found a magnetar that was in the process of fading, offering a first-hand look at how these objects pull off their disappearing act.

When the object FIRST J141918.9+394036 was discovered in the 1990s, it was among the brightest things in the universe—comparable to even quasars and galactic centers. Over the course of about 25 years, however, its radio emissions faded away to almost nothing, rendering it invisible to certain telescopes. It's thought that FIRST J141918.9+394036's incredibly bright and powerful emissions were the product of the merger between two stars or the explosion of a single, massive star, which in turn created a magnetar.

What makes the gamma rays from magnetars special is that they are very difficult to pick up—unless the beam is pointed directly at Earth, we may never be able to detect it. As it stands, the research team estimates that we're only picking up 1 in 100 of the 'afterglows' from star explosions or mergers, which can lead us to find the magnetars creating the mysterious gamma ray bursts. After these magnetars slow their rapid spinning, they may start to emit fast radio bursts, which would explain the source of those emissions, too.

If this new research is correct, scientists may have killed two cosmic mysteries with one stone.

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