Unraveling the enigma of fast radio bursts

Abstract

The mystery began in 2007, when astrophysicist Duncan Lorimer and his undergraduate physics student were combing through archival data from the Parkes Observatory in Australia. After a month of analysis, the two noticed something unusual: an extreme burst from 2001 that briefly became one of the brightest radio objects in the night sky (1). “We estimated that it put out as much energy in 5 milliseconds as the sun does in a month,” says Lorimer, a professor at West Virginia University (WVU) in Morgantown. Sightings of an FRB in 2015 at the Green Bank Radio Telescope in West Virginia helped mitigate doubts about their existence. Image courtesy of English Wikipedia/Geremia. Exactly what could be producing such prodigious amounts of power remains unknown. But since 2001, scientists have found around 18 similar astronomical events. They call them “fast radio bursts” (FRBs). Theories abound as to their origin: everything from highly magnetized neutron stars to energetic young nebula to evaporating black holes. “The joke is that the number of theories outnumber the number of known bursts,” says astrophysicist Emily Petroff of The Netherlands Institute for Radio Astronomy. Now, researchers believe they might be turning the corner on understanding these strange flashes. At the American Astronomical Society conference in January, a team announced that they had traced a repeating FRB back to a distant dwarf galaxy, the first time such an object has been triangulated to a specific spot in the sky (2). Beginning later this year, several telescope projects will be coming online that promise to uncover dozens of FRBs per day. Besides resolving a long-standing head-scratcher, scientists hope these discoveries will help them survey and study the ionized gas between galaxies, giving them insight into dark matter, dark energy, and the large-scale structure of the universe. The story of FRBs begins …