A study published in Physical Review Letters explores a new approach to detecting the gravitational wave memory effect, a phenomenon predicted by Einstein's general relativity. This effect refers to the permanent alteration in the distance between cosmic objects caused by a passing gravitational wave. Scientists suggest that existing gravitational wave observatories could capture this elusive signature, specifically from core-collapse supernovae (CCSN), which occur when massive stars over ten times the Sun's mass collapse and explode.
Core-collapse supernovae generate gravitational waves with unique characteristics due to their changing quadrupole moments during collapse. According to reports, while the amplitude of these waves is lower compared to signals from black hole or neutron star mergers, they provide critical insights into stellar interiors. Unlike electromagnetic signals, which originate from a supernova's surface, gravitational waves emerge from deep within, offering a rare glimpse into the dynamics of a collapsing star.
Challenges of Detecting Supernova Gravitational Waves
Detection of gravitational waves from CCSN has proven difficult due to their lower amplitudes, shorter durations, and complex signatures. Reports state that these waves fall below the sensitivity range of current high-frequency detectors such as advanced LIGO. However, the study indicates that low-frequency gravitational waves from CCSN exhibit a "memory" effect. This effect arises from anisotropic neutrino emissions and matter movement during collapse, leaving a non-zero gravitational disturbance.
As per reports, the research team, led by Colter J. Richardson from the University of Tennessee, analysed three-dimensional simulations of non-rotating CCSN with masses up to 25 solar masses using the CHIMERA model. Their findings revealed a distinct ramp-up in gravitational wave signals characteristic of memory with matched filtering techniques, the team concluded that signals from a 25 solar mass supernova could be detected up to 10 kiloparsecs away, a range accessible by existing observatories.
Potential for Future Research
Richardson highlighted, as per sources, the significance of exploring low-frequency gravitational waves and encouraged further investigations using the study's methodology. Future research may focus on common merger events or improvements in detector sensitivity to refine the detection of memory signals.
