{"dataset":{"slug":"gravitational-wave-operations","title":"Gravitational-Wave Operations","description":"The operational layer of multi-messenger astronomy — the gravitational-wave detection methods, the multi-messenger channels, the follow-up stages, and the scientific data products (skymaps, waveforms, parameter estimation, the GWTC catalog).","version":"1.0.0","lastGenerated":"2026-06-29","license":"CC BY-SA 4.0","entityCount":15,"sources":["ligo"]},"entities":[{"id":"gw_followup_stage:counterpart-search","name":"Counterpart Search","type":"gw_followup_stage","domain":"science","description":"The race to find the electromagnetic counterpart of a gravitational-wave event — wide-field telescopes tiling the large localization region, imaging it repeatedly to catch the one new point of light that is the merger's afterglow among millions of unrelated sources.","entryPath":"/multi-messenger/counterpart-search"},{"id":"gw_data_product:gravitational-waveform","name":"Gravitational Waveform","type":"gw_data_product","domain":"science","description":"The signal itself — the rising chirp of a compact binary as it spirals in, merges, and rings down. Matching the observed waveform against banks of theoretical templates is how a real signal is dug out of the detector noise and how its source is identified.","entryPath":"/multi-messenger/gravitational-waveform"},{"id":"mm_channel:gravitational-waves-and-gamma-rays","name":"Gravitational Waves + Gamma Rays","type":"mm_channel","domain":"science","description":"The pairing of a gravitational-wave chirp with a short gamma-ray burst. Their near-simultaneous arrival from GW170817 confirmed that neutron-star mergers cause short gamma-ray bursts, and that gravitational waves travel at the speed of light.","entryPath":"/multi-messenger/gravitational-waves-and-gamma-rays"},{"id":"mm_channel:gravitational-waves-and-light","name":"Gravitational Waves + Light","type":"mm_channel","domain":"science","description":"Observing a source in both gravitational waves and electromagnetic light — the channel that transformed astronomy when GW170817 was caught in both, pinning down where a kilonova came from and confirming that neutron-star mergers forge heavy elements.","entryPath":"/multi-messenger/gravitational-waves-and-light"},{"id":"mm_channel:gravitational-waves-and-neutrinos","name":"Gravitational Waves + Neutrinos","type":"mm_channel","domain":"science","description":"Searching for neutrinos in coincidence with a gravitational-wave event. Both messengers escape from deep inside cataclysms that light cannot penetrate, so a joint detection would probe the engines of mergers and collapses directly.","entryPath":"/multi-messenger/gravitational-waves-and-neutrinos"},{"id":"mm_channel:gravitational-waves-and-optical","name":"Gravitational Waves + Optical","type":"mm_channel","domain":"science","description":"The optical hunt for a gravitational-wave counterpart — the wide-field survey campaign that finds and follows the fading glow of a kilonova, measuring how a merger's freshly-made heavy elements light up and cool.","entryPath":"/multi-messenger/gravitational-waves-and-optical"},{"id":"mm_channel:gravitational-waves-and-radio","name":"Gravitational Waves + Radio","type":"mm_channel","domain":"science","description":"Following a gravitational-wave source into the radio, where the slow afterglow of a merger's jet ploughing into surrounding gas unfolds over weeks to months, revealing the geometry and energetics of the outflow.","entryPath":"/multi-messenger/gravitational-waves-and-radio"},{"id":"gw_data_product:gravitational-wave-transient-catalog","name":"Gravitational-Wave Transient Catalog","type":"gw_data_product","domain":"science","description":"The cumulative catalogue of confident gravitational-wave detections from the LIGO–Virgo–KAGRA observing runs — the growing census of compact-binary mergers, released as open data, from which the population of black holes and neutron stars across cosmic time is reconstructed.","entryPath":"/multi-messenger/gravitational-wave-transient-catalog"},{"id":"gw_detection_method:laser-interferometry","name":"Laser Interferometry","type":"gw_detection_method","domain":"science","description":"The technique behind the ground-based detectors: a laser beam is split down two perpendicular kilometre-scale arms and recombined, and a passing gravitational wave stretches one arm and squeezes the other by a fraction of a proton's width, shifting the interference pattern. LIGO, Virgo, and KAGRA all work this way.","entryPath":"/multi-messenger/laser-interferometry"},{"id":"gw_followup_stage:localization","name":"Localization","type":"gw_followup_stage","domain":"science","description":"Working out where on the sky a gravitational-wave source lies, from the tiny differences in when and how strongly each detector in the network registers the wave. With only two or three detectors the region can be huge — hundreds of square degrees — which is what makes the counterpart search so hard.","entryPath":"/multi-messenger/localization"},{"id":"gw_data_product:parameter-estimation","name":"Parameter Estimation","type":"gw_data_product","domain":"science","description":"Inferring the properties of a gravitational-wave source — the masses and spins of the merging objects, the distance, the orientation — by comparing the waveform against models. It is how a chirp becomes a measurement, including the standard-siren distance that probes the expansion of the universe.","entryPath":"/multi-messenger/parameter-estimation"},{"id":"gw_detection_method:pulsar-timing-array","name":"Pulsar Timing Array","type":"gw_detection_method","domain":"science","description":"Using an array of millisecond pulsars — nature's most precise clocks — as a galaxy-sized gravitational-wave detector. A passing nanohertz gravitational wave subtly shifts the arrival times of the pulsars' pulses in a correlated way; timing arrays have found evidence for a background of such waves from supermassive black-hole binaries.","entryPath":"/multi-messenger/pulsar-timing-array"},{"id":"gw_followup_stage:rapid-response","name":"Rapid Response","type":"gw_followup_stage","domain":"science","description":"The time-critical mobilisation of telescopes within minutes to hours of a gravitational-wave alert. A kilonova fades in days and the earliest light carries the most information, so automated systems and rapid human decisions decide whether the counterpart is caught at all.","entryPath":"/multi-messenger/rapid-response"},{"id":"gw_data_product:sky-localization-map","name":"Sky Localization Map","type":"gw_data_product","domain":"science","description":"The probability map of where a gravitational-wave source lies on the sky, released with each alert. Rather than a single point it is a spread of probability — often a long banana-shaped arc — that observers use to plan which patches of sky to search first.","entryPath":"/multi-messenger/sky-localization-map"},{"id":"gw_detection_method:space-interferometry","name":"Space Interferometry","type":"gw_detection_method","domain":"science","description":"Laser interferometry carried out between spacecraft millions of kilometres apart, free of the ground noise that limits Earth-based detectors. It opens the low-frequency gravitational-wave band — the mergers of massive black holes and the whir of compact binaries — that the ground detectors cannot reach. LISA is the leading example.","entryPath":"/multi-messenger/space-interferometry"}]}