First gravitational wave detection of a mass gap object merging with a neutron star

An international collaboration involving Northwestern University astrophysicists uncovers potential neutron stars and mysterious objects within the “mass gap,” the region between the heaviest known neutron star and the lightest known black star. A gravitational wave signal was detected for the first time due to a merger with hole . Gravitational wave signals alone cannot reveal the nature of this mysterious object, which has a mass 2.5 to 4.5 times that of the Sun and lies 650 million light-years from Earth. Future discoveries of similar phenomena, especially those involving bursts of electromagnetic radiation, could provide the key to solving the mysteries of the universe. “Previous evidence for mass-gap objects has been reported in both gravitational and electromagnetic waves, but this system is particularly interesting because it is the first time we have detected a mass-gap object in gravitational waves paired with a neutron star. “It’s interesting,” said Silvia Viscobeanu of Northwestern University. She led the science and contributed to the analysis. “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.” Biscoveanu is a NASA Einstein Fellow at the Northwestern Center for Interdisciplinary Exploration and Astrophysics Research (CIERA), where she collaborates with Vicki Calogera, CIERA Director and lead astrophysicist for the LIGO Science Collaboration. I am. Daniel I. Linzer, Kalogera Professor of Physics and Astronomy in Northwestern’s Weinberg College of Arts and Sciences, was a member of the science case study team. Michael Zevin, CIERA Visiting Scientist and Adler’s Planetarium Astrophysicist, led the Discovery Editorial Team and the Scientific Case Study Team.

The LIGO-Virgo-KAGRA collaboration discovered a signal from GW230529 in May 2023, shortly after the start of the fourth observation. By analyzing the signal, astrophysicists determined that it was the result of a merger between her two compact objects. One has a mass between 1.2 and 2.0 times the mass of the Sun, and the other has a mass between 2.5 and 4.5 times the mass of the Sun. The researchers say the less massive object is likely a neutron star, while the more massive object could be a black hole. However, scientists are confident that larger objects are within the mass gap. Gravitational wave observations have now measured the masses of about 200 small celestial bodies. Of these, only one other merger was most likely a compact mass gap object. Signal GW190814 originates 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. “Before we started observing the universe with gravitational waves, the properties of compact objects such as black holes and neutron stars were derived indirectly from electromagnetic observations of the Milky Way,” Zevin said. . “The idea that there is a gap between the masses of neutron stars and black holes has existed for a quarter of a century, but electromagnetic observations like this advance it.” It’s less empty than it was, and this has implications for supernova explosions that form compact objects, and for the light shows that can occur when a black hole tears apart a neutron star. ” After a maintenance break, the LIGO Hanford, LIGO Livingston, and Virgo detectors will work together to resume their fourth observation on April 10, 2024. The KAGRA detector is added later in the run. This service will continue until February 2025, with no further interruptions planned. LIGO-Virgo-KAGRA researchers will analyze data from the first half of the run and review the remaining 80 key signal candidates already identified.

source: https://www.ligo.caltech.edu/