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Fusion of a binary black hole in the presence of a third black hole
A strange signal in background noise created by a fusion between two black holes can be the first usual detection of a system of three stellar mass black holes attached to a gravitational waltz.
According to a new collaboration Ligo Virgo-Kagra, recently published in the The Astrophysical Journal Lettersdata from a 2019 binary hole collision showed signs of an anomalous acceleration that suggests the presence of a third black hole.
“This is the first international discovery of clear evidence of a third object compact at a binary hole fusion event, ”says Wen-Biao Han, Astronome of the Chinese Academy of Sciences, in the institution.
“Our data reveal that binary black holes in GW190814 they can not being formed in isolationbut they were part of a gravitational system more complexoffering significant details on the form of binary black holes, ”adds Han.
Since, in 2015, scientists have cataloged about 300 fusions – events in which binary black holes finally complete their orbital decay and collidecoalesing in a single object and sending gravitational waves to rode through the spacetime fabric.
Astronomers can analyze the signs in these ripples to determine the masses of the black holes involved, with some mergers suggesting what we call hierarchical mergers – a series of mergers that lead to increasing black holes.
According to the, this is because the black holes of stellar mass have a superior limit of mass in training – The point at which a massive star explode as supernova And he frees his outer layers, leaving a core that collapses under his own gravity to become a black hole.
Above a certain star mass, the whole set explodes Completely, core included, leaving nothing but wreckage. So if a black hole is detected above this limit, scientists infer that this black hole is inevitably Product of an earlier fusion.
GW190814 It did not involve a black hole above the mass limit. On the contrary, one of the black holes involved is considered the smallest of its type already detected, so small that oscillates on the border of being a neutral star – Only 2.6 times the mass of our sun.
The other black hole involved It was significantly greaterabout 23 solar masses. This proportion of masses is out of what is foreseen by the stellar evolution models: it is usually expected that binary systems have two comparable size objects.
The team led by Shu-Cheng Yangresearcher at the Chinese Academy of Sciences, believes that this mass proportion is indicative of a complicated past; one pair of black holes that was attracted for the gravitational attraction of a much larger third objectaround which the binary orbits.
The investigators then examined the gravitational wave data more closely. A pair of black holes in orbit of a third black hole, larger, should show extra acceleration along the line of view due to the orbital movement around the third black hole.
The investigators calculated how this would manifest themselvesand then compared their model with the GW190814 data.
According to your model, the data suggest an acceleration on the line of view of 0.0015 times the speed of light in the vacuum, with a confidence level of about 90 % – which suggests the presence of a third black hole not observed.
This result may mean that black hole mergers can, at least in some circumstances, occur in much more complicated circumstances than we knew.
The discovery also provides more evidence of hierarchical fusions – validating the existence of triple black hole systems in which mergers may occur.
