Gravitational-wave astronomy

Gravitational-wave astronomy studies cosmic objects and events by detecting and analyzing ripples in spacetime, complementing observations made with electromagnetic radiation and particles.

Gravitational wave: A propagating disturbance in spacetime generated by accelerating masses and carrying energy away from its source. These are the signals that gravitational-wave astronomy measures.
GW150914: The first directly detected gravitational-wave event, observed in 2015 and produced by two merging black holes. This event launched observational gravitational-wave astronomy.
Gravitational-wave standard siren: A gravitational-wave source whose signal provides a direct estimate of its luminosity distance. Standard sirens can measure cosmic expansion when a source's redshift is also known.
Albert Einstein: The physicist who developed general relativity, which predicts gravitational waves. His theory supplied the framework for predicting the signals later detected.
Pulsar timing array: A network of precisely timed pulsars used to detect low-frequency gravitational waves through correlated timing shifts. It probes frequencies far below those accessible to ground-based interferometers.
Laser Interferometer Gravitational-Wave Observatory: A US observatory that uses laser interferometers to detect gravitational waves. Its detectors made the first direct observation of gravitational waves.
Binary black hole: A system of two black holes orbiting a shared center of mass. Merging binary black holes produced the first detected signals.
Gravitational-wave astronomy of compact binaries: The study of merging black holes and neutron stars through their gravitational-wave signals. Compact-binary signals reveal masses, spins, and merger rates.
Joseph Weber: An American physicist who pioneered experimental searches for gravitational waves using resonant bars. His experiments helped establish gravitational-wave detection as an observational goal.
Laser Interferometer Space Antenna: A planned space-based gravitational-wave observatory using three spacecraft in a triangular formation. Its lower-frequency band will reveal massive black-hole mergers and other long-period sources.

Linked from 48 pages