Astronomers report second detection of Gravitational Waves

A second burst of gravitational waves have been detected. The same facilities that detected the gravitational waves for the first time in September 2015 have sensed the second burst on Christmas Day in the US. The waves were detected from two huge combining black holes.

The researchers said that the new set of waves have taken place due to the merger of black holes. The LIGO team said that the masses of the both objects were 14 and eight times that of the sun. The combination led to the production of a single black hole of 21 solar masses. The energy released into the space was equivalent to the mass of one star of the sun size.

This energy in the form of gravitational waves was felt in the laser interferometers of the LIGO labs in Livingston, Louisiana, and Hanford, Washington State on 25 December. Prof Bernard Schutz of Cardiff University was of the view that the detection of gravitational waves for the second time proves that first was not an isolated event.

Schutz said, “It shows the first event wasn’t just a fluke. It shows that the Universe is filled with black holes spiralling in together and merging and giving off these huge bursts of gravitational waves quite regularly. It’s a violent Universe”.

When gravitational waves were detected for the first time in September they were detected from the merger of black holes 29 and 36 times the sun’s mass. The LIGO detectors measured the waves 1.1 milliseconds apart.

It was only when the labs started working with the Italian laser interferometer, Virgo, to be started by the end of this year that a better triangulation will be achieved.

“LIGO’s first detection of merging black holes is perfectly consistent with the dynamical formation model from the Northwestern research team and is what you would expect from a globular cluster, the researchers say. Colliding black holes do not emit light; however, they do release a phenomenal amount of energy as gravitational waves. The first detection of these waves occurred Sept. 14, and the second—announced to the world this morning—occurred three months later. These events have launched a new era in astronomy: using gravitational waves to learn about the universe.”

“Thanks to LIGO, we’re not just theorists speculating anymore—now we have data,” said Frederic A. Rasio, a theoretical astrophysicist at Northwestern and senior author of the study. “A relatively simple and well understood process seems to work. Simple freshman physics—Newton’s first law of motion—explains the gravitational dynamics of the first black holes detected by LIGO.”

“We were ecstatic by the news announced earlier this year by LIGO about its first detection of colliding black holes,” said Carl L. Rodriguez, lead author of the study and a Ph.D. student in Rasio’s research group. “The findings are pretty much where we thought they would be. We look forward to working with the data from new detections.”

“Simple physical processes make the heavy black holes go to the center of the cluster,” Rasio said. “These pairs eventually merge and are detected by LIGO.” He is the Joseph Cummings Professor in the department of physics and astronomy in Northwestern’s Weinberg College of Arts and Sciences.

In their study, Rasio, Rodriguez and colleagues describe in detail the dynamical interaction processes that could form a merging binary black hole system. They also show that theoretical predictions for this dynamical formation channel are, in general, far more robust than models for the other main channel for forming binary black holes, based on the evolution of massive stars in isolated binaries (not in star clusters).”

According to a report in US News by SETH BORENSTEIN, ” Astronomers say they’ve heard the echoes of two more crashing black holes — a discovery that hints that the unseen violence of the universe may be pretty common. They detected a second gravitational wave. That’s the warp in the fabric in the cosmos that Albert Einstein predicted a century ago in his theory of general relativity, something that results only from the most massive space crashes. It’s something that can’t be seen and Einstein thought would never be detected, but scientists have found a way to hear it — first one note, in September 2015, and now two.”

“This event really does establish that there are quite a few merging black holes in the nearby universe,” said Penn State University physicist Chad Hanna, one of the more than 1,000 scientists who wrote the study released Wednesday at an astronomy conference and published in the journal Physical Review Letters . “The universe is full of these tremendous collisions that are depositing tremendous energy.”

A report published in the NPR News said, “It’s like a Jell-O that we all swim in,” says Gabriela González, a researcher at Louisiana State University and head of LIGO’s scientific collaboration. Space-time is a lot stiffer than Jell-O. But the gravitational pull of very, very massive things can cause it to bend and shake. When that happens, the distances between objects will begin to shift. “It will get longer and shorter and longer and shorter without us doing anything, without us feeling anything,”

Upgrades completed in 2014 finally allowed the LIGO detectors to see gravitational waves. Last fall, they snagged their first signal — from two black holes colliding. Then in December, the detectors saw another collision, which occurred around 1.4 billion light-years from Earth. This time, researchers say, the black holes were about 14 and 8 times the mass of our sun. They combined to create a black hole, 21 times as massive as the sun. An entire sun’s worth of mass was also converted into gravitational waves that passed through the Earth.

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