An article submitted for publication in the “Astrophysical Journal Letters” reports the discovery of eight repeating Fast Radio Bursts (FRBs). The CHIME/FRB collaboration, the team of scientists who use the CHIME radio telescope to search for these phenomena, gathered evidence of these new Fast Radio Bursts after the announcement of the second repeating one’s discovery months ago. This suggests that these phenomena are not so rare compared to non-repeating ones but that we have only recently found a way to detect them.
Fast Radio Bursts were detected for the first time in 2007 by analyzing archive data collected in 2001 and still are a mystery because such powerful radio emissions require an energy estimated of about that emitted by the Sun in 80 years despite their duration a few milliseconds. In 2016 the detection of the first repeating Fast Radio Burst was announced, the second one was announced in January 2019 but the big announcement has arrived now, with the detection of eight of them.
The CHIME (Canadian Hydrogen Intensity Mapping Experiment) radio telescope in Canada saw the so-called first light on September 7, 2017 and began its hunt for Fast Radio Bursts in 2018 using four half-cylinders instead of the classic circular antennas. The results are excellent, with hundreds of non-repeating Fast Radio Bursts and the 8 repeating ones analyzed in this research.
What started as a low-cost experiment – where the expression still means $16 million – to study radio waves from the early universe was also used as a hunter for Fast Radio Bursts. Lately CHIME’s results are getting great attention after an initial calibration phase in which the observations seemed caused by interferences or instrumental glitches.
The data of the new repeating Fast Radio Bursts, detected between September 16, 2018 and February 22, 2019, at last offer the possibility of building the first statistics on these phenomena and therefore to compare them with non-repeating Fast Radio Bursts. For example, every burst in one of the repeating events seems to last longer than non-repeating events, around 10 milliseconds per burst against a millisecond for a single event.
However, it may be still too early to assess the various differences to try to understand the origin of these phenomena. The first analyzes suggest the possibility of different mechanisms of origin: magnetar-type neutron stars are the first suspects but it’s possible that other sources exist as well. The success of the CHIME radio telescope is important to solve the mysteries around these extremely energetic events.
