At the 238th meeting of the American Astronomical Society (AAS), held in recent days, Researchers presented the results of fast radio bursts detections made using the CHIME radio telescope between July 25, 2018, and July 1, 2019, the first year of research with this instrument. Researchers from the CHIME collaboration detected 535 fast radio bursts including 61 bursts from 18 known repeating sources. The catalog presented on this occasion considerably expands the number of known fast radio bursts offering a lot of new information on these still mysterious phenomena. The differences between the characteristics of single and repeating bursts indicate even more that there are at least two mechanisms that produce them.
The findings of the CHIME (Canadian Hydrogen Intensity Mapping Experiment) radio telescope are truly revolutionizing the study of fast radio bursts. Its structure formed by half-cylinders, physically very different from that of the classic circular antennas used in typical radio telescopes, together with the instrumentation to process the received signals, allows performing surveys following the Earth rotation, as the antennas are stationary. CHIME is an instrument designed to map the distribution of matter in the universe and some changes in the design made it perfect to detect phenomena such as fast radio bursts. From this point of view, it’s much better than traditional radio telescopes.
In the first year of its operations, the CHIME radio telescope made it possible to quadruple the number of fast radio bursts known. The catalog presented by the CHIME collaboration includes 535 events including 61 bursts from 18 previously known repeating sources. The researchers estimated that around 9,000 events detectable by radio telescopes like CHIME occur in the entire sky every day.
The amount of fast radio bursts detected by the CHIME radio telescope also allowed obtaining some statistics. For example, they appear to be evenly distributed in space. This suggests that most come from sources outside the Milky Way.
The results obtained by the CHIME radio telescope confirm the hypothesis that there are at least two mechanisms behind these events. In fact, the 61 bursts from repeating sources made it possible to carry out more sophisticated analyzes thanks to the signal processing equipment. The result was that single bursts and repeating bursts showed different characteristics clearly visible in their emissions’ spectra.
Research in recent years offered clues to links between some fast radio bursts and magnetars. However, a study currently only available in a preprint on a fast radio burst locates it in a globular cluster, where the presence of a magnetar among old stars is unlikely. This is another clue of the existence of different mechanisms to generate these events.
The one just released is only the first catalog of fast radio bursts. In the meantime, the CHIME radio telescope kept on detecting these events collecting much more data on them. These radio emissions require very high energy and yet sensitive instruments are needed to detect them. CHIME could be the key to understanding their nature.