This page has been prepared by the LIGO Scientific Collaboration (LSC) and the Virgo Collaboration to inform the broader community about a candidate astrophysical event observed by the gravitational-wave detectors, and to make the data around that time available for others to analyze.
The candidate event occurred at GPS time 1128678900.44 == October 12, 2015 at 09:54:43.44 UTC. It was recovered with a network signal-to-noise ratio of 9.7 and a significance of 1.7 sigma. The candidate event was detected in data from the LIGO Hanford and LIGO Livingston observatories.
| Quantity | Value | Upper/Lower error estimate | Unit |
|---|---|---|---|
| Primary mass | 23 | +18 -6 | M sun |
| Secondary mass | 13 | +4 -5 | M sun |
| Chirp mass | 15.1 | +1.4 -1.1 | M sun |
| Total mass | 37 | +13 -4 | M sun |
| Final mass | 35 | +14 -4 | M sun |
| Final spin | 0.66 | +0.09 -0.10 | |
| Radiated gravitational-wave energy | 1.5 | +0.3 -0.4 | M sun c2 |
| Peak luminosity | 3.1 | +0.8 -1.8 | 1056 erg/s |
| Luminosity distance | 1000 | +500 -500 | Mpc |
| Source redshift z | 0.20 | +0.09 -0.09 |
The data from the observatories from which the science is derived:
| Hanford | Livingston | |
|---|---|---|
| 32 seconds (event is 16.44 seconds from start) | hdf5 gwf txt.gz |
hdf5 gwf txt.gz |
| 4096 seconds (event is 2048.44 seconds from start) | hdf5 gwf txt.gz |
hdf5 gwf txt.gz |
| Hanford | Livingston | |
|---|---|---|
| 32 seconds (event is 16.44 seconds from start) | hdf5 gwf txt.gz |
hdf5 gwf txt.gz |
| 4096 seconds (event is 2048.44 seconds from start) | hdf5 gwf txt.gz |
hdf5 gwf txt.gz |
The skymap can be visualized in astronomical context with the Skymap Viewer:
The skymaps are represented as HEALPIX-FITS files in equatorial frame, available gzipped:
A python library for reading such files is healpy. A very simple healpy code to work with LIGO-Virgo skymaps is here. A large number of simulated skymaps is available here and here.
The Laser Interferometer Gravitational-Wave Observatory (LIGO) consists of two widely separated installations within the United States — one in Hanford, Washington and the other in Livingston, Louisiana — operated in unison as a single observatory. LIGO is operated by the LIGO Laboratory, a consortium of the California Institute of Technology (Caltech) and the Massachusetts Institute of Technology (MIT). Funded by the National Science Foundation, LIGO is an international resource for both physics and astrophysics.
The GEO600 project aims at the direct detection of gravitational waves by means of a laser interferometer of 600 m armlength located near Hannover, Germany. Besides collecting data for gravitational wave searches, the GEO600 detector has been used to develop and test advanced instrumentation for gravitational wave detection.
The LIGO Scientific Collaboration (LSC) is a group of scientists seeking to make the first direct detection of gravitational waves, use them to explore the fundamental physics of gravity, and develop the emerging field of gravitational wave science as a tool of astronomical discovery. The LSC works toward this goal through research on, and development of techniques for, gravitational wave detection, and the development, commissioning and exploitation of gravitational wave detectors. The LSC carries out the science of the LIGO and GEO600 Observatories. Participation in the LSC is open to all interested scientists and engineers from educational and research institutions.
There is a technical details page about the data linked above, and feel free to contact us.