Astrophysicist Abraham Loeb of Harvard University in the United States suggested that the gravitational waves recorded by LIGO (Laser Interferometric Gravitational Observatory) originated from the merger of two black holes inside a giant star. The author published the results of the research on the website arXiv.org, and briefly reports about it by the New Scientist edition.
Loeb explained his assumption by the powerful gamma-ray bursts observed by the Fermi telescope, which, presumably, are associated with gravitational waves discovered by the LIGO observatory - perturbations of space-time. According to the scientist, the X-ray signal recorded by LIGO is too powerful for the merger of two black holes exclusively.
As Loeb showed, the observed signal can be obtained from a giant star, inside which is a pair of merging black holes. After the two gravitational objects merge, the surrounding matter crashes into the black holes and releases a powerful burst of X-rays. In this case, the volume of the luminary should exceed the solar one by hundreds of times.
A pair of black holes in a star could, according to Loeb, arise from its rapid rotation. In this case, the core of the star is deformed - it takes a dumbbell-like shape and splits into two parts, each of which later (after the termination of thermonuclear reactions in the star) evolves into an independent black hole. Loeb's hypothesis has not yet received experimental confirmation.
The Fermi Space Observatory, located in near-Earth orbit, recorded a weak gamma signal 0.4 seconds after the LIGO observatories detected space-time waves. Astrophysicists working for Fermi began searching for the source of gravitational waves in the electromagnetic bands an hour after the discovery of LIGO.
The gravitational observatory found out that the source of the event GW150914, associated with gravitational waves, is located in the southern hemisphere. In the same place, in the constellations of Cetus or Pisces, the Fermi telescope discovered a source of unusual gamma rays. The observatory could not determine its location more precisely. Fermi's data were not confirmed by the INTEGRAL telescope (International Gamma-Ray Astrophysics Laboratory).
The nature of the signal received by Fermi is not explained by the emission of magnetars, pulsars or neutron stars. The statistics collected by the space telescope are not enough to declare a discovery (there is a possibility that the signal is generated by fluctuations in the atmosphere). Scientists will continue to collaborate with LIGO.
Gravitational waves were recorded on September 14, 2015 at 05:51 a.m. ET (13:51 p.m. ET) at two twin detectors of the LIGO laser interferometric gravitational wave observatory located in Livingston, Louisiana and Hanford, Washington) in the USA.
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Disturbances are generated by a pair of black holes (29 and 36 times heavier than the Sun) in the last fractions of a second before they merge into a more massive rotating gravitational object (62 times heavier than the Sun). The merger of black holes happened 1.3 billion years ago (for so long the gravitational disturbance spread to the Earth).