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|While the Arecibo radio telescope could only localize the fast radio burst to the area inside the two circles, the VLA was able to pinpoint it as a dwarf galaxy within the square, shown at the intersection of the cross hairs in the enlarged box.|
The origin of a fast radio burst in this type of dwarf galaxy suggests a connection to other energetic events that occur in similar dwarf galaxies, said co-author and UC Berkeley astronomer Casey Law, who led development of the data-acquisition system and created the analysis software to search for rapid, one-off bursts.
“All these threads point to the idea that in this environment, something generates these magnetars,” Law said. “It could be created by a super-luminous supernova or a long gamma ray burst, and then later on, as it evolves and its rotation slows down a bit, it produces these fast radio bursts as well as continuous radio emission powered by that spin-down. Later on in life, it looks like the magnetars we see in our galaxy, which have extremely strong magnetic fields but rotate more like ordinary pulsars.”
“We are the first to show that this is a cosmological phenomenon. It’s not something in our backyard. And we are the first to see where this thing is happening, in this little galaxy, which I think is a surprise,” Law said. “Now our objective is to figure out why that happens.”
Looking for transients
“The overall theme, first with the Allen Telescope Array and now with the VLA, is to use these interferometers as high-speed cameras, taking the sensitive imaging capabilty of the telescope, cranking up the data rate and improving our algorithms to get access to these millisecond time-scale transients,” he said. “We really pushed hard to capture this terabyte-per-hour datastream reliably and set up a real-time platform for extracting these very faint fast bursts from that massive datastream.”
“We observed for about 40 hours earlier last year and saw nothing,” he said. “Then we started a new campaign in the fall of 2016, and in our first observation we saw one. Then we observed for another 40 hours or so and saw eight more bursts. So this thing just suddenly turned on.”
“Finding the host galaxy of this FRB, and its distance, is a big step forward, but we still have much more to do before we fully understand what these things are,” Chatterjee said.