Direct evidence of the existence of gravitational waves is something that has long eluded researchers, however new research has suggested that adding just one of the proposed detectors in Japan, Australia and India will drastically increase the expected rate of detection.
In a study published today, Friday, 27 May, in IOP Publishing’s journal Classical and Quantum Gravity, Professor Bernard Schutz, of the Albert Einstein Institute, Germany, demonstrated that an additional detector would more than double the detection rate of gravitational waves and could double the amount of sky being covered. It was estimated last year that by 2016 the existing network of four detectors would be able to detect, on average, 40 neutron-star merger events per year by monitoring the gravitational waves they produce. Using a computer analysis, this study showed that by performing optimal coherent data analysis, the network could theoretically detect 160 events per year.
The positioning of the current network actually makes such a large increase in detection rate unlikely; however Schutz has shown that using any of the three additional locations would change this dramatically. The addition of all three new detectors would enable the detection of around 370 events a year, which could increase to 500 events after a few years of operation.
These detectors are most likely to encounter ‘short bursts’ of gravitational waves that arise from two stars or two black holes orbiting each other. The sheer acceleration of these types of events cause a distortion in space time – known as a gravitational wave – that spreads outwards like ripples moving across a lake. Professor Schutz said, “The improvements brought about by new detectors are much bigger than the proportionate extra investment required. Even moving an existing LIGO detector to Australia brings two to four times the number of good-quality detections and also dramatically improves the direction information for the events.”