A bright burst of X-rays has been discovered by NASA’s Chandra X-ray Observatory in a galaxy 6.6 billion light years from Earth. This event likely signalled the merger of two neutron stars and could give astronomers fresh insight into how neutron stars — dense stellar objects packed mainly with neutrons — are built.
When two neutron stars merge they produce jets of high energy particles and radiation fired in opposite directions. If the jet is pointed along the line of sight to the Earth, a flash, or burst, of gamma rays can be detected. If the jet is not pointed in our direction, a different signal is needed to identify the merger.
The detection of gravitational waves – ripples in spacetime – is one such signal. Now, with the observation of a bright flare of X-rays, astronomers have found another signal, and discovered that two neutron stars likely merged to form a new, heavier and fast-spinning neutron star with an extraordinarily strong magnetic field.
“We’ve found a completely new way to spot a neutron star merger,” says Yongquan Xue of the University of Science and Technology of China and lead author of a paper appearing in Nature. “The behaviour of ...