Did LIGO, the gravitational wave detector, detect a cosmic event that was set into play about 12 billion years when it discovered gravitational waves? Researchers believe the first set of black holes detected by LIGO in September last year which merged, were those leftover from two massive suns that may have existed around 12 billion years ago.
According to The Verge, simulations of the early universe by a computer model called Synthetic Universe led to these predictions. The masses of the merging black holes were estimated at 36 and 29 times mass of the sun, resulting in a combined mass range that Synthetic Universe predicts the LIGO can detect.
"These progenitor stars probably formed either about 2 billion years or, with a smaller probability, 11 billion years after the Big Bang," Krzysztof Belczynski, lead author of the study that described findings of the simulations in a Nature article.
The massiveness of the black holes indicates the stars were massive, probably about 100 solar masses. Stars of such mass are likely poor in metals and thus were formed in the early universe. However, the researchers did not rule out the small possibility of these stars existing more recently as some recognized regions of the universe are known to have metal-poor stars.
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.
