In February this year, the Laser Interferometer Gravitational-Wave Observatory (LIGO) announced that its researchers have succeeded in spotting Albert Einstein’s gravitational waves. A few days ago, the research foundation revealed that the waves have been detected once again. Now, a research group from the Massachusetts Institute of Technology (MIT) and Australian National University said that LIGO researchers can go deeper in space in search of the waves with a new technology that they have developed.
The technology will make LIGO more sensitive to gravitational waves, ripples in the fabric of space-time resulted by the most violent and energetic processes in the cosmos, as per the MIT and Australian National University researchers.
The researchers said that a new squeezed vacuum source could be introduced in the LIGO detector that may double the detector’s sensitivity. It will allow LIGO to detect even those gravitational waves that are weaker and are from a source distant in the universe.
The team wants that the Advanced LIGO detectors should be used to detect farthest gravitational waves, or those waves that are weakest, said Nergis Mavalvala, lead researcher of the team from the MIT. “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”, Mavalvala continued. Now, there’s an impetus that can decrease that noise, the researcher added.
A report published in Forbes said, “Before these gravitational waves were seen, all we had were theoretical models of what stellar-mass black holes might be. Contrary to the supermassive ones at the centers of galaxies, where we could measure the stars in orbit around them, the high-energy radiation emitted from the infalling matter, or the energy of the jets leaving them, all we had for these objects — the most common black holes in the Universe — was a story.”
We knew that stars that were massive enough would not only fuse hydrogen into helium during their main lifetime, and then turn into a red giant, fusing helium into carbon, but would go beyond that, heating up internally to achieve fusion reactions that less than 1% of stars will ever attain. Carbon fusion will begin, then oxygen, then silicon and sulphur and finally the core will be filled with iron, nickel and cobalt: elements too stable to fuse into heavier ones under normal conditions.
Stars need to be many times the mass of the Sun — at least 8-to-10 but perhaps even more — to reach this stage. At this point, the inner core of the star, since there’s no more fusion occurring, runs out of its prime source of radiation, which was the only thing holding the nuclei inside up against gravitational collapse. So the core of the star collapses, catastrophically, and implodes, giving rise to a Type II Supernova.
According to a story published on the topic by The Verge, “In February, scientists at the LIGO observatory made history when they announced the first ever detection of gravitational waves. These ripples in the fabric of space-time came from two black holes that spun around each other several times per second before merging in a violent, energetic explosion. Now, researchers have calculated the likely origins of those black holes. A new study argues that they probably came from two massive suns that formed about 12 billion years ago — or two billion years after the Big Bang.”
The simulation even includes a synthetic LIGO detector to determine the types of objects that the observatory would detect over time. Using this model, Belczynski and his team were able to look back to the start of the Universe and calculate the types of stars that formed the black holes that LIGO detected.
Moving forward, Belczynski’s models show that LIGO will be detecting more black hole mergers similar to this one. And the more mergers that the observatory detects, the more it validates and refines what the Synthetic Universe model has predicted about star evolution. “We are now moving toward precision astronomical science with gravitational waves,” said Christopher Fryer, a research scientist at Los Alamos National Laboratory, who was not involved with the study. “The detections are already telling us about the nature of massive star evolution.”