Fast radio bursts are powerful and mysterious millisecond bursts of radio waves. Astronomers have yet to determine what causes them.
Last week, the first detection of a single radio burst's origin was announced. Previously, only a fast repeating radio burst had been traced to its home galaxy. A repeating burst is easier to trace than a single, quick radio signal.
Researchers at the California Institute of Technology's Owens Valley Radio Observatory discovered the point of origin for FRB 190523. Its galaxy, similar in size to our own Milky Way galaxy, is 7.9 billion light-years away. The discovery was published on Tuesday in the journal Nature.
The observatory was used to make observations over the course of 54 days before and after the event.
"Finding the locations of the one-off FRBs is challenging because it requires a radio telescope that can both discover these extremely short events and locate them with the resolving power of a mile-wide radio dish," said Vikram Ravi in a statement, study author and assistant professor of astronomy at Caltech.
The observatory was designed to capture such intense, quick events like fast radio bursts.
"At OVRO, we built a new array of ten 4.5-meter dishes that collectively act like a mile-wide dish to cover an area on the sky the size of 150 full moons," Ravi said. "To do this, a powerful digital system ingests and processes an amount of data equivalent to a DVD every second."
The Deep Synoptic Array-10, funded by the National Science Foundation, will include 110 radio dishes. It is expected to come online in 2021.
"The DSA is expected to discover and localize more than 100 FRBs per year," said Richard Barvainis, program director at the National Science Foundation for the Mid-Scale Innovations Program. "Astronomers have been chasing FRBs for a decade now, and we're finally drawing a bead on them with new instruments. Now we have a chance of figuring out just what these exotic objects might be."
Learning more about the origin of fast radio bursts can help astronomers ultimately determine what causes them.
Previously, the repeating burst came from a small galaxy full of forming stars. The single burst announced last week came from a massive galaxy that has low rates of star formation. And this new single burst comes from a "mellow" galaxy.
"This finding tells us that every galaxy, even a run-of-the-mill galaxy like our Milky Way, can generate an FRB," Ravi said.
Fast radio bursts may also allow astronomers to study the way matter is distributed in the universe.
"Most matter in the universe is diffuse, hot, and outside of galaxies," Ravi said. "This state of matter, although not 'dark,' is difficult to observe directly. However, its effects are clearly imprinted on every FRB, including the one we detected at such a great distance."
Meanwhile, the mystery behind the cause of fast radio bursts remains, causing speculation.
People love to believe that they're from an advanced extraterrestrial civilization, and this hypothesis hasn't been ruled out entirely by researchers at Breakthrough Listen, a scientific research program dedicated to finding evidence of intelligent life in the universe.