Friday, November 26, 2021

Astronomers have discovered a “tsunami” of gravitational waves. That’s where they come from

The most recent series of gravitational wave observations yielded the largest catch.

In less than five months, from November 2019 to March 2020, LIGO-Virgo interferometers recorded 35 massive gravitational wave events. On average, that’s almost 1.7 gravity wave events every week while running.

This represents a significant increase over the 1.5 weekly average event detected in the previous run and the result that has increased the total number of events to 90 since the first historical gravitational wave detection in September 2015.

“These discoveries represent a tenfold increase in the number of gravitational waves detected by LIGO and Virgo since they began observing,” said astrophysicist Susan Scott of the Australian National University in Australia.

“We have registered 35 events. This is a huge amount! In contrast, we made three detections during our first observation cycle, which lasted four months in 2015-16. This is truly a new era for the detection of gravitational waves, and the number of discoveries is growing. revealing so much information about the life and death of stars throughout the universe. “

Of the 35 new discoveries, 32 are most likely the result of merging pairs of black holes. This is when pairs of black holes in close orbit are attracted by mutual gravity, eventually colliding to form one more massive black hole.

This collision causes ripples in space-time, like the ripples that occur when you throw a stone into a pond; astronomers can analyze these ripples to determine the properties of black holes.

Infographic showing the masses of all announced black hole mergers to date. (LIGO-Virgo / Aaron Geller / Northwestern University)

The data revealed a number of black hole masses, the most massive of which is about 87 times the mass of the Sun. This black hole merged with a satellite 61 times the mass of the Sun, resulting in a single black hole, 141 times the mass of the Sun. This event is named GW200220_061928.

Another merger created a black hole 104 times the mass of the Sun; both are considered intermediate mass black holes, in the mass range from 100 to about a million solar masses, in which very few black holes have been found.

GW200220_061928 is also interesting because at least one of the black holes involved in the merger falls into what we call the upper mass gap. According to our models, black holes over 65 solar masses cannot form from a single star like stellar-mass black holes.

Read Also:  Hubble has captured the startling 'eye' of a massive stellar explosion

This is because the progenitor stars are so massive that their supernovae, known as supernovae with coupled instability, should completely obliterate the star’s core, leaving nothing to gravitationally collapse into a black hole.

This suggests that the 87 solar masses black hole may have been the product of a previous merger. GW200220_061928 is not the first thing to do with a black hole in the upper mass gap, but its discovery does suggest that hierarchical black hole mergers are not uncommon.

And yet another event involves an object in the lower mass gap – a gap of black holes, the mass of which is 2.5-5 times the mass of the Sun. We have not finally found a neutron star larger than the first or a black hole smaller than the second; an event called GW200210_092254 included an object clocked at 2.8 solar masses. Astronomers have concluded that this is probably a very small black hole.

“By looking at the masses and spins of black holes in these binaries, one can understand how these systems even formed,” said Scott.

“It also raises some really fascinating questions. For example, was the system originally formed from two stars that went through their life cycles together and eventually became black holes? Or did two black holes collide together in a very dense dynamic environment like the center of a galaxy? “

The other three events out of 35 were associated with a black hole and something even less massive, probably with a neutron star. These events are of great interest to astronomers, as they can reveal the substance inside a neutron star – if we ever find one that emits light. By discovering more such mergers, we can better understand how they actually happen.

“We are only now beginning to appreciate the amazing variety of black holes and neutron stars,” said astronomer Christopher Berry of the University of Glasgow in the UK.

“Our latest results prove they come in many sizes and combinations – we’ve solved some long-standing puzzles, but we’ve also uncovered some new puzzles. Using these observations, we are closer to unraveling the mysteries of how stars, the building blocks of our universe, evolve. “

The team article has been submitted for publication and can be found on the arXiv preprint server.

Nation World News Desk
Nation World News is the fastest emerging news website covering all the latest news, world’s top stories, science news entertainment sports cricket’s latest discoveries, new technology gadgets, politics news, and more.
Latest news
Related news
- Advertisement -