Astronomers who study the region of space said a recent unusual X-ray glow recently seen in the sky could be an afterglow of the kilonova outburst that was produced by the merger, possibly generated by a shockwave from the explosion that slammed into dust in the region of space surrounding the explosion.
As specified in a ScienceAlert report, the said X-ray glow observed in the sky and a half years following an epic collision between a pair of neutron stars is a first for science.
Alternatively, the glow could be generated by materials expelled during the explosion falling back onto the newly combined object, possibly a low-mass black hole.
Either way, the report indicated, such a phenomenon occurs to have been detected in the past. According to Aprajita Hajela, an astronomer from Northwestern University, "We have entered uncharted territory here," in investigating a neutron star merger's aftermath.
GW170817 Event
Hatela explained that they were looking at something new and unusual for the first time. The astronomer added that this occurrence allows them to examine and understand how new physical processes have not been observed before.
The outburst itself, initially in August 2017, was an epic occurrence. For the first time, astronomers were able to detect the moment two neutron stars sealed together in an increasingly rotting orbit had banged together and merged.
Not only was the occurrence called GW170817, captured with the use of a new field of gravitational wave astronomy, although in light across the spectrum.
Such a merger generated a kilonova blast, an outburst 1,000 times brighter than a classical nova. Investigation of the light of this blast showed that neutron star collisions generate gamma-ray bursts, that near light-speed jets are expelled from the blast, and that, in the robust environment during the outburst, heavy metals like uranium, platinum, and gold are formed.
Totally New Observation in Astronomy
As indicated in a similar Florida Digital News report, since this was a totally new observation, astronomers continued observing the region of the sky where it took place, roughly 132 million light-years from the Solar System.
Essentially, in X-ray wavelengths, the astronomers noticed something unusual. Nine days following the gamma-ray burst, the source began to glow through the spectrum, brightening to a peak 160-days after the merger.
Then, the glow quickly faded. Such a fading occurrence was interpreted as a "relativistic jet." Nonetheless, while the glow faded through most of the spectrum, from 2020, it plateaued a steady light persisting in the space's darkness, in X-ray wavelengths.
Raffaella Margutti, an astrophysicist of the University of California at Berkeley, said that the X-rays stopped fading fast was "our best evidence" yet that something on top of a get is being spotted in X-rays in this source.
Detection of 'Kilonova Afterglow'
According to Kate Alexander, an astronomer from Northwestern University, further investigation of GW170817 could have "far-reaching implications."
She added the detection of a kilonova afterglow would infer that the merger did not instantaneously generate a black hole. Alternatively, such an object may provide astronomers a chance to examine how matter is falling onto a black hole after a few years from its birth.
This study is due for publication in the latest issue of The Astrophysical Journal Letters and is currently available on the arXiv preprint server.
Report about the possible afterglow of kilonova explosion is shown on Wonder World's YouTube video below:
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