Researchers at the University of Minnesota Twin Cities College of Science and Engineering led a study aimed at improving the detection of gravitational waves, which are ripples in space and time. The research is part of the LIGO-Virgo-KAGRA (LVK) Collaboration, a network of gravitational wave interferometers across the world. The goal of the research is to send alerts to astronomers and astrophysicists within 30 seconds after the detection of gravitational waves, ultimately improving the understanding of neutron stars, black holes, and the production of heavy elements like gold and uranium. The findings of this study were recently published in the Proceedings of the National Academy of Sciences (PNAS).
Gravitational waves interact with spacetime by compressing it in one direction while stretching it in the perpendicular direction. Current state-of-the-art gravitational wave detectors are L-shaped and measure the relative lengths of the laser using interferometry, a measurement method based on interference patterns produced by two light sources. Detecting gravitational waves requires precise measurements, equivalent to measuring the distance to the nearest star down to the width of a human hair. Neutron stars, formed when massive stars explode in supernovas, are the smallest, most dense stars known to exist.
In the latest simulation campaign, data from previous observation periods was used, and simulated gravitational wave signals were added to test the performance of the software and equipment upgrades. The software developed in this research can detect the shape of signals, track their behavior, and estimate the masses involved in the event, such as neutron stars or black holes. Once a gravitational wave signal is detected, alerts are sent out to subscribers like astronomers or astrophysicists to communicate the location of the signal in the sky. With the upgrades in this observing period, alerts can now be sent out faster, in under 30 seconds after the detection of a gravitational wave, allowing for quick follow-up research.
With the improved detection capabilities, astronomers and astrophysicists can gain valuable insights into how neutron stars behave, the nuclear reactions between neutron stars and black holes colliding, and the production of heavy elements like gold and uranium. This information could help advance the understanding of the cosmos and the processes that lead to the formation of these elements. The researchers involved in this study, including Ph.D. student Andrew Toivonen from the University of Minnesota Twin Cities School of Physics and Astronomy, see the potential for this software to enable the detection of faint gravitational wave signals from neutron star collisions, providing valuable information for further research.
The current observing run using the Laser Interferometer Gravitational-Wave Observatory (LIGO) is the fourth of its kind, scheduled to continue through February 2025. Scientists have made improvements to signal detection between observing periods and plan to continue analyzing the data to make further enhancements. The ultimate goal is to send out alerts even faster in future observing runs, allowing for quicker responses and more detailed observations of gravitational wave events. The collaboration between researchers across the world in the LVK network demonstrates the importance of international cooperation in advancing our understanding of the universe and the phenomena that shape it.
