UBC astronomers help unveil 128 new gravitational wave signal candidates

The international LIGO-Virgo-KAGRA (LVK) collaboration—including UBC astrophysicists—has released a new version of the Gravitational Wave Transient Catalog which contains 128 new significant gravitational wave signal candidates. The update includes the recently announced GW231123—likely the highest-mass binary black hole merger observed to date.

The gravitational wave detector network also released interferometric strain data from the first part of the fourth observing run (O4) that took place from May 24, 2023 through January 16, 2024. More detailed information can be found on the Gravitational Wave Open Science Center.

“This catalog represents a big step forward in our understanding of gravitational waves in our universe,” said Dr. Rhiannon Udall, a UBC postdoctoral researcher and the LIGO-Virgo-KAGRA data management lead for the catalog methods paper.

“In addition to some really exciting individual events, we’re seeing so many events that we are learning a lot about the populations of black holes and neutron stars. That lets us explore some big questions about the lives of these objects. How many are born from the deaths of massive stars, and how many come from previous mergers of black holes?”

Extracting a high rate of gravitational-wave signals from noisy detector data can be very challenging. The large-scale LIGO detectors are enormously complex and often generate ‘glitches’ and other noise features in the data that can confuse or obscure searches for gravitational-wave signals. UBC researchers are major leaders in delivering calibrated, clean LIGO detector data, effectively improving the reach of these remarkable instruments. 

“These new results showcase the performance improvements of the LIGO detectors relative to previous observing runs—we’re seeing many more mergers and mergers with unprecedented signal fidelity,” said Dr. Jess McIver, who served as deputy spokesperson for the LIGO Sscientific Ccollaboration during the data collection period. 

The UBC team made key contributions to LIGO data calibration, detector monitoring and large-scale computing contributions made through the Digital Research Alliance of Canada that powers a significant fraction of LIGO-Virgo-KAGRA results. Dozens of Canadian student researchers have contributed to LIGO-Virgo-KAGRA results during O4 through the UBC LIGO team, including undergraduate students based at UBC and two high school students currently attending Vancouver Technical Secondary and Burnsview Secondary in Delta. 

The collaboration will continue to share results from its ongoing fourth observing run, with each new discovery adding to our rapidly expanding understanding of the graveyard of dead stars and the universe's most extreme events.