Portsmouth researchers enable discovery of remarkable gravitational wave signal Researchers at the Institute of Cosmology and Gravity (ICG) at the University of Portsmouth have helped detect a remarkable gravitational wave signal that could hold the key to solving the mysteries of the universe.

The discovery was announced today (5 April) in the LIGO-Virgo-KAGRA collaboration involving more than 1,600 scientists around the world, including members of the ICG, which aims to detect gravitational waves and use them for research. This is according to the latest results published by the study. Fundamentals of natural science. In May 2023, shortly after the start of the fourth LIGO-Virgo-KAGRA observation, the LIGO-Livingston detector in Louisiana, USA, observed a gravitational wave signal caused by a collision between a putative neutron star and a small celestial body with a diameter of 2.5 degrees. 4 or 5 times the mass of the sun. Neutron stars and black holes are both compact objects, the dense remnants of massive stellar explosions. What makes this signal, called GW230529, so appealing is the mass of the heavier object. It lies within the possible mass gap between the heaviest known neutron star and the lightest black hole. Gravitational wave signals alone cannot reveal the nature of this object. Future discoveries of similar phenomena, especially those related to bursts of electromagnetic radiation, could help solve this problem. “This discovery is the first exciting result from LIGO-Virgo-KAGRA’s fourth observational run, suggesting that similar collisions between neutron stars and low-mass black holes are more likely than previously thought. “This shows that there is a high probability that it exists,” Dr. Jess McIver, Assistant Professor, University of British Columbia, Deputy Public Relations Officer for LIGO Scientific Cooperation. This phenomenon has only been observed by gravitational wave detectors, making it increasingly difficult to determine whether it is real or not. Dr. Gareth Cabourn Davies, a research software engineer at ICG, has developed a tool to search for events in a single detector. He says, “Confirming an event by observing it with multiple detectors is one of the most powerful tools for separating signal from noise.” Using appropriate models of background noise This allows events to be evaluated even when no other detectors are present. what we saw. ” Until the discovery of gravitational waves in 2015, the masses of stellar-mass black holes were primarily determined using his X-ray observations, and the masses of neutron stars were determined using radio observations. The resulting measurements he classified into two distinct regions, with a gap between them of about two to five solar masses. Over the years, a small number of measurements have widened the mass gap, but this gap is still hotly debated among astrophysicists. Analysis of signal GW230529 shows that it results from the merger of two compact objects, one with a mass between 1.2 and 2.0 times the mass of the Sun, and another with a mass of 1.2 to 2.0 times the mass of the Sun. It has a mass more than twice that. Gravitational wave signals do not provide enough information to determine with certainty whether these compact objects are neutron stars or black holes, but it is possible that the lighter objects are neutron stars and the more massive objects are neutron stars. It could be a black hole. Scientists participating in the LIGO-Virgo-KAGRA collaboration are confident that more massive objects lie within the mass gap. Gravitational wave observations have now measured the masses of about 200 small celestial bodies. Only one other of these mergers may have been a compact object with a mass gap. Signal GW190814 results from the merger of a black hole with a compact object that exceeds the mass of the heaviest known neutron star and may lie within the mass gap. . “Previous evidence for mass-gap objects has been reported in both gravitational and electromagnetic waves, but this system is particularly exciting because it is the first gravitational-wave detection of a mass-gap object paired with a neutron star. ,” says Dr. Silvia Viscobeanu of Northwestern University. “Observations of this system have important implications for both the theory of binary evolution and the theory of merging of compact objects with their electromagnetic counterparts.”

The fourth observation is scheduled to last 20 months, including a several-month break to maintain the detector and make many needed improvements. As of January 16, 2024, when the current suspension began, a total of 81 significant signal candidates have been identified. GW230529 is the first to be released after extensive research. The fourth observation will continue on April 10, 2024, with the joint operation of the LIGO Hanford, LIGO Livingston, and Virgo detectors. Observations will continue until February 2025, and no further observation suspensions are planned.

source: https://www.port.ac.uk/research/research-groups-and-centres/institute-of-cosmology-and-gravitation