
The leftovers from the first neutron star smashup we鈥檝e ever seen have surprised us. The beam of light that jetted out of the explosion has gotten even brighter in the three months since the Laser Interferometer Gravitational Wave Observatory (LIGO) and other observatories spotted the collision. This brightening may mean that similar jets of x-rays and gamma radiation are more complicated than we thought.
At the beginning of December, astronomers used the Chandra X-ray Observatory to take another look at the spot where we watched a neutron star smash-up in August. They saw three times more X-ray radiation in the area than directly after the explosion that generated the gravitational waves LIGO saw.
鈥淚nitially, we thought that this jet from the neutron stars exploding was a simple cone of light,鈥 says at NASA鈥檚 Goddard Space Flight Center in Maryland. 鈥淣ow we are thinking that was a naive picture and the jet is not so simple.鈥
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If the jet of light was a cone like the beam of a torch, it would look like a circle from a head-on view, and we should have seen it get bright and then dim as its path crossed our line of sight. But the fact that it鈥檚 gotten even brighter hints that the beam is a more complicated shape, perhaps with wings of light coming off the sides of the cone.
The brightening could be caused by the shape. Just after the smashup we may have been seeing the thinner wings of light, and now we could be looking directly down the brighter barrel of the beam, says Troja.
鈥淲e don鈥檛 know whether this structure that we see is just peculiar to this event or whether it鈥檚 a general property of all the gamma ray bursts,鈥 blasts of high-energy radiation that we now know can be created by neutron star collisions, Troja says. Either way, she says, 鈥渨e definitely need to revise our idea of how these jets form.鈥
Read more: The 5 biggest discoveries from the hunt for gravitational waves