Source of a fast radio burst located for the first time

Nature : Since 2007 astronomers have detected more than a dozen extremely bright radio-wave bursts, each of which lasted no more than a few milliseconds. Most of these fast radio bursts (FRBs) were found in data archives, making it impossible to track the source of the signals. But on 18 April 2015 the Parkes radio telescope in Australia spotted an FRB in real time. Evan Keane of the Jodrell Bank Observatory near Manchester, UK, led a team that organized several other observatories to try to track the signal. The Australia Telescope Compact Array found what appeared to be the fading afterglow of the signal, which allowed the Subaru Telescope on Mauna Kea, Hawaii, to focus the search down to the most likely source: a relatively old elliptical galaxy 6 billion light-years away. Keane’s team suspects the FRB was caused by the collision of two neutron stars. Knowing the source of an FRB opens up the ability to use the bursts for other purposes. The radio signal got smeared as it passed through space in a way that let Keane’s team calculate how much material it passed through. The researchers’ calculation suggests that intergalactic regions contain up to half the ordinary matter that cosmologists have been unable to directly detect.