Black holes collide—and UBC researchers helped detect the signal

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      In the world of astronomy, this is big news.

      On May 21, 2019, the U.S.-based Laser Interferometer Gravitational-Wave Observatory and the Virgo Interferometer in Italy detected a gravitational wave suggesting that a "cataclysmic cosmic event" had occurred, according to a UBC news release.

      It turned out that the cause was the merger of two black holes. These holes are parts of space that have such strong gravitational fields that they suck in everything, including radiation.

      UBC assistant professor of physics and astronomy Jess McIver was among a group of international scientists who published this research in two peer-reviewed journals, Physical Review Letters and the Astrophysical Journal.

      They reported that one of the black holes had 85 times the mass of the sun; the other was 65 times the sun's mass.

      It occurred about 17 billion light years from Earth.

      The signal has been dubbed GW190521 and it peaked at a lower frequency than any other black hole merger observed in the past.

      Jess McIver

      "When I first saw the shape of this signal I was a bit worried. It looked quite similar to common LIGO detector noise,” McIver said in the news release. “But as we analyzed it and saw how consistent the data was between the detectors, and as we worked through all of our environmental sensors and our usual checks to make sure that there was nothing that could have possibly propagated across the earth that might mimic this, we were able to confirm it.”

      According to the UBC news release, McIver's group analyzed "mountains of data" to confirm the finding.

      “We have to establish a high level of confidence in this discovery, since this is the first time a system like this has been observed,” UBC research associate Evan Goetz said. “We find that GW190521 is the first conclusive observation of an intermediate mass black hole. In order to make a confident detection, we need a deep understanding of LIGO and Virgo noise sources that could mimic a signal like this.”

      Some black holes are believed to be millions to billions of times the mass of the sun.