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Distant black hole collision is the largest and most distant ever seen by LIGO und Virgo inventors
The fourth gravitational-wave detection from LIGO and Virgo’s third observation stream released today is the biggest news: the largest link of the two black holes observed to date. When the Universe was half its current age the black hole collision formed 142 solar mass black holes. This is the first direct observation of the birth of an intermediate-mass black hole. The pair’s heavier black hole is even more amazing: at 85 times the mass of our Sun, it may not be in line with current understanding of stellar eruptions, but it may be born from a previous binary link. It is not known whether this signal, GW190521, is the first observed representative of a new class of binary black holes or at the upper end of a broad mass spectrum. Scientists at the Max Planck Institute for Gravitational Physics and the University of Leipzig in Hanover, Botswana and Hannover have made significant contributions to the discovery and its interpretation.
Today LIGO Scientific Collaboration and Virgo Collaboration have published the results of the latest study and their astronomical implications in the journal Physics Review Letters and Astronomy Journal. The GW190521 was observed by dual LIGO detectors and the Virgin Inventor on May 21, 2019 – initially their third joint surveillance run, O3, which began on April 1, 2019.
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My. Fischer, H. Fiber, a. Simulation of the collaboration between Poonano (Max Planck Institute for Gravitational Physics), Extreme Space Times (SXS)
Heavy black hole connection number simulation (GW190521)
“From the beginning, this signal, only a tenth of a second long, challenged us to identify its origin,” said Alessandra Bhuvanno, director of the Max Planck Institute for Gravitational Physics (Albert Einstein Institute; AEI) at Botstam and College. Professor of Parks at the University of Maryland. He adds, “But despite the short duration, black hole connections, as predicted by Einstein’s theory of general relativity, were able to match the signal with the expected one, and we realized it was witnessing for the first time. The birth of an intermediate-mass black hole from a black hole parent may have been born from a previous binary connection. ”
A short message from a galactic distance
GW190521 is the fourth gravitational-wave signal emitted from O3, and it is short: it lasts one-tenth of a second and has four gravitational-wave cycles in the frequency band of the detectors (corresponding to two orbits of black holes). During this short period, before the signal is terminated by connecting two black holes, its frequency rises from 30 Hz to 80 Hz.
GW190521 is not only the binary black hole connection with the highest total masses ever seen, it is also the most distant. Due to the large mass, very strong gravitational waves – with an energy equal to eight times that of the Sun – were emitted, so that the signal was louder and more recognizable over larger cosmic distances. The connection of about 150 suns occurred when the Universe was halfway to its present age: about seven billion years ago.
Witness the birth of an intermediate mass black hole
The remnant of the fusion of the two black holes, one with 66 and 85 solar masses, is the black hole of 142 solar masses. It is heavier than any LIGO / virgin black hole previously observed and is the first direct observation of the birth of an intermediate mass black hole. These elusive, previously mentioned, and previously indirectly observed black holes are 100 to 100,000 times more massive by their mass at the centers of galaxies, much larger than the known lighter stellar black holes and much smaller than the massive miraculous black holes.
Simulation of the number of two black holes emitting and merging gravitational waves. The black holes have large and almost equal masses, one 3% larger than the other. The simulated gravitational wave signal corresponds to the observation made by the LIGO and the virgin gravitational wave detectors on May 21, 2019 (GW190521).
© My. Fischer, H. Fiber, a. Poonano (Max Planck Institute for Gravitational Physics), collaboration with Extreme Gap Simulation (SXS)
A black hole that should not be
The pair’s heavier black hole is even more astonishing: 85 times its solar mass does not match the patterns of our Sun star evolution.
“From our understanding of the age and growth of stars, we expect to find black holes with masses less than 65 or more than 120 solar masses, but nothing in between,” explains Frank Om, head of the Independent Max Planck Research Group at AEI. Hannover. “The 85 solar mass black holes in the GW190521 source system should not be exactly at that interval, it should not be! This could mean two things: our understanding of the evolution of stars is incomplete or something different has happened here. ”
A gap in the black hole masses
According to current understanding, stars that give birth to black holes with a mass of 65 to 120 solar masses do not explode into supernovae, so no such black holes have formed. Stars experience one or more short episodes of instability, in each of which they emit a significant portion of their mass instead of exploding. At the end of the process, a supernova explodes and a star remains, forming a black hole of less than 65 solar masses. Stars forming black holes of more than 120 solar masses are expected to collapse directly without the fireworks of a supernova.
The gap that occurs in the black hole mass spectrum is called the “pair instability” gap. It is named for the physical process that causes episodes of mass shedding.
Connection of connected black holes or stars
The binary system may have had a more complex origin story. Uncertainties in understanding how stars form can allow black holes with a mass of more than 65 solar masses to be born from a supernova explosion. However, LIGO and Virgo researchers believe that the most likely explanation for the formation of 85 solar-mass objects is the previous connection of two small black holes or two massive stars.
Something completely different
The signal is well described, and Einstein’s general theory of relativity accepts the prediction of a binary black hole connection, with LIGO and virgin scientists looking at other possible explanations for observation in a supplement. Emergence from cosmic strings – an imaginary object that could have evolved in the early universe – is not possible. The signal is unlikely to come from a centrifugal supernova, which is accompanied by electromagnetic or neutrino signals.
The GW190521 observation corresponds to coming from a closer and less massive binary black hole connection, whose gravitational waves are distorted by gravity. It may also have formed from primitive black holes that formed at the beginning of the universe before stars were born. However, LIGO and Virgo researchers have concluded that these two interpretations are not very feasible compared to the usual link scenario. Finally, the signal may have been generated by connecting two black holes in the elliptical orbit. But to verify that, accurate signal samples, including fingerprints of elliptical orbits derived from general relativity, must be matched against the signal. They are not yet available.
New class of binary black holes?
“GW190521, we do not know whether this amazing discovery and the first observation of an intermediate mass black hole are completely new binary black holes or the high-mass end of the original spectrum we have seen so far,” said A.E.I. Danceman. “Soon, if we analyze all the binary black hole connections found by LIGO and Virgo in their third observation stream, we can find out more.”
Future release will analyze the large sample of binary black hole connections found in the first half of O3 (O3a April 1 to October 1, 2019).
AEI researchers contributed to the detection and analysis of GE190521. They provided precise models of gravitational waves from the fusion of black holes, for the first time, multipole moments beyond the forerunner and dominance of the black holes’ vortices. Those features embedded in the waveform are important for obtaining unique information about the properties of the source. The high-performance computer cluster in AEI Podstam was used to create waveform models for “hypotheses” analysis.
More than 50 additional gravity-wave candidates from O3
LIGO and Virgo researchers have issued warnings for 56 potential gravitational-wave events (candidates) in O3, which lasted from 1 April 2019 to 27 March 2020. So far four candidates have been confirmed and made public. LIGO and Virgo scientists are examining the remaining 52 candidates, and detailed follow-up analyzes confirm their astronomical appearance.
LIGO Scientific and Virgo Collaborations
LIGO is funded by the National Science Foundation (NSF) and is run by Caltech and MIT, which guides the project with LIGO in mind. Funding for the Advanced LIGO Project The NSF has made significant contributions and contributions to this project, along with Germany (Max Planck Society), the United Kingdom (Scientific and Technical Facilities Council) and Australia (Australian Research Council-Oz Grove). About 1,300 scientists from around the world are participating in this effort through the LIGO Scientific Collaboration, which includes the Geo collaboration. A list of additional partners is available https://my.ligo.org/census.php.
Virgo Cooperation currently has more than 500 scientists, engineers and technicians from 99 companies from Belgium, France, Germany, Hungary, Italy, the Netherlands, Poland and Spain. The European Gravity Laboratory (EGO) runs the Virgin Inventor near Pisa in Italy, and the Center National de la Research Scientific (CNRS) in France, and the Istitudo Nacionale de Physica Nuclear (INFN) in Italy And funded by Nikef in the Netherlands. A list of virgin cooperation members can be found here https://public.virgo-gw.eu/the-virgo-collaboration/
