A recent study published in Nature Astronomy examines the discovery of what astronomers are dubbing “ultra-fast radio bursts”, a new type of fast radio bursts (FRBs) that the team determined lasts for a mind-boggling ten millionths of a second or less. Traditionally, FRBs have been found to last only thousandths of a second, but this study builds on a 2021 study that hypothesized FRBs could possibly last for millionths of a second. This also comes after astronomers recently announced the discovery of the oldest and farthest FRB ever observed, approximately 8 billion light-years from Earth.
“During our group meetings, we often talked about it,” said Mark Snelders, who is a Ph.D. candidate at ASTRON and the University of Amsterdam (the Netherlands), along with being lead author of the most recent study and a co-author on the 2021 study. “By coincidence, I found out that there was a public dataset that we could use for this.”
For the study, the team was able to obtain five hours of data on a known FRB called FRB 20121102A, which was discovered in November 2012 and is located approximately three billion light-years from Earth, along with being considered the first known repeating FRB, according to a 2022 study. The data was obtained from the Breakthrough Listen project, which is a worldwide scientific collaboration with the goal of finding evidence of extraterrestrial intelligence, with the data specifically coming from the Breakthrough Listen at Green Bank portion of the Open Data Archive.
Upon obtaining the data, the team took the first 30 minutes and split each second into 500,000 separate images, then incorporated machine learning and software filters to isolate outliers within the data to identify eight ultra-fast radio bursts lasting a mere ten millionths of a second or less. For context, ten millionths of a second is equivalent to 0.00001 seconds.
The researchers note, “In detecting and characterizing these microsecond-duration bursts, we show that there exists a population of ultra-fast radio bursts that current wide-field FRB searches are missing due to insufficient time resolution. These results indicate that FRBs occur more frequently and with greater diversity than initially thought. This could also influence our understanding of energy, wait time, and burst rate distributions.”
While questions remain as to how these ultra-fast radio bursts are produced, the team does expect to identify more ultra-fast radio bursts in the future. However, the difficulty lies in finding data files capable of being split into 500,000 separate images per second, as some files lack the necessary specifications to make such splitting possible.
The long-term goal for the tea, is to use FRB data to map the space that exists between stars and galaxies, which they hope will help them gain better insights into the interactions between galaxies and the gas in the surrounding environment.
FRBs are some of the most mysterious celestial phenomena ever studied ever since they were first discovered in 2007, and astronomers have made incredible strides in both understanding their potential origins and the number of FRBs that exist in the universe. This includes discovering that most FRBs come from outside our Milky Way Galaxy.
However, in 2020, astronomers found one source of FRBs was from a magnetar within our own Milky Way Galaxy. Also, while FRB 20121102A is designated as the first known repeating FRB, a 2023 study identified 25 regularly repeating FRBs found using the Canadian Hydrogen Intensity Mapping Experiment (CHIME), which is located in British Colombia, Canada, and has found more than 1000 FRBs to date.
What new discoveries about FRBs ultra-fast radio bursts will astronomers make in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
Here is a paper with results suggesting some repeater FRBs are related to neutron “starquakes”:
” We analyse nearly 7,000 bursts reported in the literature for the three most active sources of FRB 20121102A, 20201124A, and 20220912A, and find the following characteristics that are universal in the three sources. A clear power-law signal of the correlation function is seen, extending to the typical burst duration (? 10 msec) towards shorter time intervals (?t). The correlation function indicates that every single burst has about a 10–60 per?cent chance of producing an aftershock at a rate decaying by a power law as ? (?t)?p with p = 1.5–2.5, like the Omori–Utsu law of earthquakes. The correlated aftershock rate is stable regardless of source activity changes, and there is no correlation between emitted energy and ?t. We demonstrate that all these properties are quantitatively common to earthquakes, but different from solar flares in many aspects, by applying the same analysis method for the data on these phenomena. These results suggest that repeater FRBs are a phenomenon in which energy stored in rigid neutron star crusts is released by seismic activity.”
[Fast radio bursts trigger aftershocks resembling earthquakes, but not solar flares
Tomonori Totani, Yuya Tsuzuki
Monthly Notices of the Royal Astronomical Society, Volume 526, Issue 2, December 2023.]