Pulsar timing arrays listen for nanohertz gravitational waves
Millisecond pulsars are cosmic clocks; networks of radio telescopes time their pulses for years, hunting correlated residuals that a passing gravitational-wave background would imprint.
Those waves oscillate at nanohertz frequencies — periods of years — expected from orbiting supermassive black-hole binaries across the universe. A Hellings–Downs spatial pattern among many pulsars is the fingerprint of a true gravitational-wave signal.
Patience is the detector. Pulsar timing arrays turn the Galaxy’s clocks into an Earth-sized observatory for the slowest gravitational waves.
Comments
0 comments