So far, March has been a busy month for scientists trying to catch a glimpse of ephemeral radio events, such as fast radio bursts (FRBs). Radio astronomers have recently detected three of these FRB events, including the brightest ever recorded.
FRBs are huge emissions of radio waves that last for a few milliseconds. They happen all over the sky and are mostly discovered serendipitously as, in all but one case, they don’t repeat. So far researchers have detected 33 FRBs and while they are gaining a better understanding of them, there is still a lot that we don’t know.
All three of the latest signals were detected at the CSIRO’s Parkes Radio Telescope in Western Australia. The first one, FRB 180301, was detected on March 1. FRB 180309 was detected 8 days later, and FRB 180311 just two days ago. FRB 180309 is particularly interesting as it has a signal-to-noise ratio of 411, making it more than 4.5 times brighter than the next best detection.
“The burst on 9 March was by far the brightest one we’ve seen,” Professor Maura McLaughlin, from West Virginia University in Morgantown, told New Scientist.
“While astronomers don't know all that much about FRBs – only tens of bursts have ever been detected – we can infer some intriguing details about them,” Danny Price, Breakthrough Listen Project Scientist for Parkes, said in a post about the discovery of FRB 180301.
“Firstly, they exhibit a tell-tale sweep in frequency that suggests they are incredibly far away: billions of light years. FRBs travel billions of years to get to us, and only last a few milliseconds, suggesting the emission mechanism is short-lived. For us to detect them clearly after such a long journey, they have also to be insanely bright.”
Being so bright, they have to be produced by some incredibly powerful events. Cataclysms involving black holes and neutron stars have been suggested, as they could release such dramatic levels of energy in a one-off event. The origin of the only repeating radio burst, known as FRB 121102, is to do with neutron stars. However, some researchers think that all FRBs repeat and it's just a question of waiting for them to do so.
Estimates suggest that 10,000 FRBs might be detectable from Earth every single day. Unfortunately, due to limited resources, only a tiny fraction of these are actually detected.
[H/T: New Scientist]