Once in a while, the cosmos unleashes powerful yet short flashes. These millisecond-long events can be visible billions of light years away from their sources in other galaxies, because in their ultra-brevity, they can generate as much energy as the Sun does in one year.
What exactly produces them is a mystery, but scientists are getting closer to determining their progenitors with every new flash they find. A Canadian-led CHIME project announced a recent sighting of this enigmatic blast — called a fast radio burst (FRB) — on Wednesday.
This FRB is special. The new FRB signal brims with frequency information according to CHIME, which is short for the Canadian Hydrogen Intensity Mapping Experiment. They’ve collected more components to this signal than over 99.5 percent of other FRBs in their survey. This pulse is also unusually long. Named FRB 20191221A, its total duration was roughly 3 seconds.
Scientists published a new paper about FRB 20191221A on Wednesday in the journal Nature, describing it as “an outlier in the FRB population.”
Why it matters — “This detection raises the question of what could cause this extreme signal that we’ve never seen before, and how can we use this signal to study the universe,” Daniele Michilli, co-author of the new work, states in an announcement describing the discovery. “Future telescopes promise to discover thousands of FRBs a month, and at that point we may find many more of these periodic signals.”
Michilli says the FRB is packed with “remarkably precise” peaks, “emitting every fraction of a second — boom, boom, boom — like a heartbeat.”
This behavior tells the team that the source of this FRB could be a magnetar, an ultra-dense stellar corpse known as a neutron star that also features a very strong magnetic field.
FRB 20191221A could also be a “pulsar on steroids,” Michilli says. A pulsar is another type of neutron star that rapidly spins around its axis. If the poles of a pulsar are angled towards Earth, the emissions cast off at these points create a blinking radio signal, as the poles swish into view, then away, and so forth.
What’s next — For now, CHIME continues collecting these objects’ calling cards. With enough information about these unique signals, astronomers can harness their regularity to study the expansion of the cosmos.
CHIME officials say in their mission statement that “the digitized signals collected by CHIME will be processed to form a 3-dimensional map of hydrogen density,” the most abundant element in space, “which will be used to measure the expansion history of the Universe.”
