Talk about rocking the cradle.听Sharp new images have identified a throng of newborn stars as the source of a fast radio burst.听The discovery strengthens the idea that these brief pulses of radio waves arise from newly formed neutron stars, super-dense objects just 20 kilometres across.
During the past decade, astronomers have detected about two dozen fast radio bursts from all over the sky. Each lasts just a few milliseconds, and attempts to explain them have invoked everything from supermassive black holes to little green men.
Until recently, we didn鈥檛 even know for sure whether the bursts arose in our galaxy or beyond. But in January, researchers announced a breakthrough.听They found the home of a fast radio burst named FRB 121102: a small galaxy in the constellation Auriga 2.4 billion light years from Earth.
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Now, Cees Bassa of the Netherlands Institute for Radio Astronomy in Dwingeloo and his colleagues have used the Hubble Space Telescope to study the galaxy.
鈥淭he Hubble observations allow us to get a very sharp image,鈥� says team member of McGill University in Montreal, Canada. 鈥淭here is a very bright spot of star formation, and this FRB lies bang inside it.鈥�
Meanwhile, Japanese astronomers led by of Tohoku University in Sendai used the 8.2-metre Subaru Telescope in Hawaii to target the galaxy.听Their images rival Hubble鈥檚 because adaptive optics undid the usual blurring created by Earth鈥檚 atmosphere.
The Hubble and Subaru images show that the star-forming complex lies on the small galaxy鈥檚 outskirts. Hubble鈥檚 handiwork puts the galaxy鈥檚 visible diameter at about 20,000 light years, one-sixth that of the Milky Way.听The stellar nursery is 6200 light years from the galaxy鈥檚 centre and spans 4400 light years, far larger than any known in the Milky Way.
Prolific galaxy
鈥淚t鈥檚 an extraordinary galaxy,鈥� says of the National Radio Astronomy Observatory in Socorro, New Mexico.听鈥淩elative to its small size, it鈥檚 making stars at a prolific rate.鈥�
That points to the cause of fast radio bursts.听鈥淚t鈥檚 telling us that they probably occur in young neutron stars,鈥� says of Washington University in St Louis, Missouri.
Many astronomers already favour that explanation because the short duration of the bursts suggested the source was tiny.听Neutron stars fit the bill, and young, fast-spinning ones have plenty of energy to release.听They form when short-lived massive stars die in their stellar nurseries.
But no one yet knows whether the same idea explains other fast radio bursts.听FRB 121102 is unique:听astronomers have seen it flash about 30 times but the others only once.
Katz suspects they may all have the same cause, but Frail says, 鈥淚 would be reluctant to draw such broad conclusions based on a sample of one.鈥�
Journal reference:听 and
