RESUMEN
Binary systems of supermassive black holes are promising sources of low-frequency gravitational waves (GWs) and bright electromagnetic emission. Pulsar timing array GW searches for individual binaries have been limited to only a few candidate systems due to computational demands, which get worse as more pulsars are added. By modeling the GW signal using only components from when the GW passes Earth (rather than also each pulsar), we find constraints on the binary's total mass and GW frequency that are similar to a full signal analysis, yet â¼70 times more efficient.
RESUMEN
We search for a first-order phase transition gravitational wave signal in 45 pulsars from the NANOGrav 12.5-year dataset. We find that the data can be modeled in terms of a strong first order phase transition taking place at temperatures below the electroweak scale. However, we do not observe any strong preference for a phase-transition interpretation of the signal over the standard astrophysical interpretation in terms of supermassive black hole mergers; but we expect to gain additional discriminating power with future datasets, improving the signal to noise ratio and extending the sensitivity window to lower frequencies. An interesting open question is how well gravitational wave observatories could separate such signals.