LIGO will detect up to 1,000 black hole collisions annually: astronomers predict

The Laser Interferometer Gravitational-wave Observatory (LIGO) will detect as many as 1,000 collisions and mergers of black holes annually once it attains full sensitivity sometime early next decade, astronomers have predicted.

The prediction, which recently published online in the journal Nature, is based on computer simulations of more than one billion evolving binary stars and information provided by the most recent astronomical & astrophysical observations.

Daniel Holz, an assistant professor of physics & astronomy at the University of Chicago, said LIGO has already detected two black-hole binary stars in a range of masses, and discovery of more would enable them to test their results more rigorously.

Speaking on the topic, Holz said, “Here we simulate binary stars, how they evolve, turn into black holes, and eventually get close enough to crash into each other and make gravitational waves that we would observe.”

However, Krzysztof Belczynski of Poland-based Warsaw University said some calculations showed that once LIGO attains its full sensitivity it will detect merely one pair of colliding massive neutron stars per 1,000 detections of the far more enormous black-hole collisions.

The research paper is the latest in a long series of publications, topping a decade of analyses where researchers theorized that the universe has creased several black-hole binary systems in the mass range that are close enough to out planet for LIGO to detect.

The study paper published in the scientific journal Eurek Alert informed…

“Researchers from the Massachusetts Institute of Technology (MIT) and Australian National University have developed new technology that aims to make the Advanced Laser Interferometer Gravitational-Wave Observatory
(LIGO) even more sensitive to faint ripples in space-time called gravitational waves. Scientists at Advanced LIGO announced the first-ever observation of gravitational waves earlier this year, a century after Albert Einstein predicted their existence in his general theory of relativity. Studying gravitational waves can reveal important information about cataclysmic astrophysical events involving black holes and neutron stars.”

“In The Optical Society’s journal for high impact research, Optica, the researchers report on improvements to what is called a squeezed vacuum source. Although not part of the original Advanced LIGO design, injecting the new squeezed vacuum source into the LIGO detector could help double its sensitivity. This would allow detection of gravitational waves that are far weaker or that originate from farther away than is possible now.”

“There are many processes in the universe that are inherently dark; they don’t give off light of any color,” said Nergis Mavalvala, part of the MIT Kavli Institute for Astrophysics and Space Research team and a leader of the research team. “Since many of those processes involve gravity, we want to observe the universe using gravity as a messenger.”

Researchers from the California Institute of Technology and MIT conceived, built, and operate identical Advanced LIGO detectors in Livingston, Louisiana and Hanford, Washington. Each observatory uses a 2.5-mile long optical device known as an interferometer to detect gravitational waves coming from distant events, such as the collision of two black holes detected last year.

“We want to use the Advanced LIGO detectors to sense the farthest gravitational wave or weakest gravitational wave possible,” said Mavalvala. “However, this is limited by the quantum fluctuations of the laser light, which create a certain level of noise. If a gravitational wave is weaker than that level of noise, then we can’t detect it. Thus, we have a big impetus to decrease that noise, and we can do that using our squeezed vacuum source.”

According to a report in CS Monitor by Calla Cofield, “There was big news in astrophysics this week: An experiment detected ripples in space-time, known as gravitational waves, created by two black holes colliding in space 1.4 billion light-years from Earth. That certainly sounds . complicated. But what’s the big deal, exactly? Why are scientists so excited about this new discovery? What does it tell them about the universe? Let’s break it down.”

But first, let’s back up a bit and talk about Albert Einstein. He was a smart guy – he figured out a lot of really subtle stuff about the universe, including that space is not a fixed, rigid backdrop, like a stage on which cosmic events play out. Instead, Einstein showed that space is flexible and influenced by the objects and events within it. Very massive objects create curves in space, kind of like the way a bowling ball curves a mattress when placed on top of it.

A report published in the HNGN News said, Interestingly, Belczynski and his team also used Synthetic Universe to predict that LIGO will be able to up its detection rate after it reaches full sensitivity. When it resumes observations later this year, it could detect about 60 mergers. “Our calculations predict detections of about 1,000 black-hole mergers per year with total masses of 20-80 solar masses once second-generation ground-based gravitational-wave observatories reach full sensitivity,”

The observatory has detected two confirmed and one potential merger, proving right Belczynski and his team who predicted the first of gravitational waves to be detected would be those from binary black hole mergers and not those from neutron stars.

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