newest gravitational waves Running Monitor has recorded the furthest distance to date.
In less than five months, from November 2019 to March 2020, the LIGO-Virgo interferometer recorded 35 massive gravitational waves. On average, that’s about 1.7 gravitational wave events each week for the duration of the run.
This is a significant increase from the weekly average of 1.5 events detected in the previous round, and as a result has increased the number of events to 90 since the first gravitational wave detection made history in September 2015.
“This discovery represents a tenfold increase in the number of gravitational waves that LIGO and Virgo have detected since they began observing,” Astrophysicist Susan Scott said:from the Australian National University in Australia.
“We found 35 events. It was incredible! Instead, we made three discoveries in our first observation, which lasted four months in 2015-16. This is really a new era of gravitational wave discovery and more and more discoveries reveal a lot. information about life and death.” stars throughout the universe.”
Of the 35 new discoveries, 32 are most likely the result of fusions between pairs black hole. This occurs when a pair of black holes in close orbit are pulled by mutual gravity, and eventually collide to form a single, more massive black hole.
This collision sends ripples through space-time, like the ripples produced when you throw a rock into a pond; Astronomers can analyze the ripples to determine the characteristics of the black hole.
A graph showing the masses of all black hole mergers announced so far. (LIGO-Virgo/Aaron Geller/Northwestern University)
The data revealed a cluster of black holes, with the largest recorded at about 87 times the mass of the Sun. This black hole combines with a companion with a mass 61 times the mass of the sun, resulting in a black hole with a mass 141 times the mass of the sun. This event is named GW200220_061928.
The final merger resulted in a black hole with a mass 104 times the mass of the Sun. Both are considered medium-mass black holes, with masses ranging from 100 to about 1 million solar masses, with very few black holes detected.
GW200220_061928 is also interesting, because at least one of the black holes involved in the merger lies in what we call the upper mass gap. According to our model, black holes larger than 65 solar masses cannot consist of a single star, as stellar-mass black holes do.
That’s because the precursor star was so massive that it became a supernova – known as Unstable pair supernova It should completely erase the star’s core, leaving nothing to collapse by gravity into the black hole.
This suggests that the 87 solar-mass black holes may be the product of an earlier merger. GW200220_061928 isn’t the first to include black holes in the upper mass gap, but its findings suggest that hierarchical black hole merging is not uncommon.
Another event involved an object in a lower mass gap – a black hole gap between 2.5 and 5 times the mass of the Sun. We have not conclusively found a neutron star larger than the former, or a black hole smaller than the latter; The event called GW200210_092254 involves recording an object at 2.8 solar masses. Astronomers have concluded that it may be a very small black hole.
“Seeing the mass and rotation of black holes in this binary system shows how this system was put together in the first place,” Scott said.
“It also raises some really cool questions. For example, did the system originally form from two stars that went through their life cycles together and eventually became a black hole? Or are the two black holes strung together in a very dense and dynamic environment like at the center of a galaxy?”
The other three of the 35 events involved a black hole and something less massive, possibly a neutron star. These events are of great interest to astronomers, because they may reveal what is inside a neutron star – if we ever detect it emitting light. By discovering more of these mergers, we can begin to build a better understanding of how they actually happened.
“It is only now that we are beginning to appreciate the incredible diversity of black holes and neutron star, ” Astronomer Christopher Berry said: From the University of Glasgow, UK
“Our latest results prove that they come in all sizes and combinations — we’ve solved some old mysteries, but also discovered some new ones. With these observations, we are closer to solving the mystery of how stars, the building blocks of our universe, evolve.”
The team paper has been submitted for publication, and can be found on the preprint server arXiv.
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