Strange Radio Bursts Detected From Distant Galaxy Finally Tracked Down
Is someone calling us from beyond Milky Way?
A few years ago, astronomers have detected distant galaxy that is emitting an extremely powerful radio blasts. After speculations about where it is coming from, scientists said they finally have the answer. The explanations were laid down in a report published in Nature and Astrophysical Journal Letters.
Fast Radio Bursts (FRB), as defined by Washington Post are extremely rapid pulses of radio waves,that emit power of about 500 million suns. Because of their unpredictability, scientists have recorded just 18 of these signals, but they suspected that there could be hundreds and thousands more.
As per the study, the FRB is coming from a dwarf galaxy some three billion light-years away.
Cornell astronomer Shami Chatterjee, the lead author of the paper, alongside her team examined data from Karl G. Jansky Very Large Array (VLA), a network of 27 radio telescopes spread over an extensive area in New Mexico and relied on scientists at the Gemini Observatory in Hawaii to look for the source of the FRB called FRB 121102.
"For a long time, we came up empty, then got a string of bursts that gave us exactly what we needed," said Casey Law, of the University of California at Berkeley in a press release.
"Once we were able to accurately pinpoint the burst's location in the two-dimensional sky we enlisted the 8-meter Gemini North telescope on Maunakea in Hawai‘i to characterize the corresponding host galaxy," added Paul Scholz formerly of McGill University and now with the National Research Council of Canada (NRC).
In addition, using a powerful network of European radio telescope, the team was able to get a high-resolution image of the FRB 121102. The team concluded that the strong signals are coming from the center of the dwarf galaxy, which appears to be occupied by a supermassive black hole.
Meanwhile, National Geographic said the team cannot pinpoint yet what are causing the outbursts, but at least they were able to trace the source. The report added that there are various hypotheses pertaining to its cause. First, the black hole might be causing the flash of energy. Next, the burst might be the gaseous remnant of a supernova. And lastly, there might be a neutron star or magnetar orbiting the galaxy's supermassive black hole, creating an unknown type of interaction that is releasing the energy.
"It is surprising that the host would be a dwarf galaxy," Shriharsh Tendulkar of McGill University in Montreal, Canada said. "One would generally expect most FRBs to come from large galaxies which have the largest numbers of stars and neutron stars. Neutron stars - remnants of massive stars - are among the top candidates to explain FRBs."