科学家探测到一束60亿光年外的电波
Scientists have detected a burst of radio waves from six billion light years away, one of a handful they've discovered in the past decade -- and this time they have clues about its source. Canadian Institute for Advanced Research (CIFAR) Global Scholar Alumnus Kiyoshi Masui (University of British Columbia) is the lead author on a Dec. 2 paper in the journal Nature that details the remarkable findings. A team of scientists including Masui and CIFAR Senior Fellow Ue-Li Pen (University of Toronto) and Jonathan Sievers (University of KwaZulu-Natal) analyzed 700 hours of archival data from the National Science Foundation's (NSF) Green Bank Telescope (GBT).
They discovered the burst and found the region of space it came from was highly magnetized, suggesting it could be related to either a recently exploded star -- a supernova -- or else the gas-clouded inside of a nebula forming new stars. Another possibility is that it came from the dense inner regions of its host galaxy.
The finding advances our limited knowledge about fast radio bursts (FRBs), which last only a split second but carry more energy than our Sun emits over a few months. Scientists have puzzled over them since they were discovered 10 years ago.
"Astronomers in particular, we love a mystery," says Masui. "That's the compelling thing about these. You have these phenomena that are very energetic, appear to be coming from half way across the Universe, and we just have no idea what they are."
After previous studies and detections from different telescopes ruled out equipment errors and noise, scientists are looking more deeply at cosmic explanations. There are many diverse theoretical models proposing explanations for fast radio bursts, including one that suggests neutron stars spinning extra fast could send out FRBs as they slow down and collapse into black holes. Other theories point to superconducting cosmic strings or evaporating black holes. The new evidence could help scientists home in on the most plausible theories.
"We're starting to uncover clues about the environment of the sources," Masui says.