Data release for event GW170814
This page has been prepared by the LIGO Scientific Collaboration (LSC) and the Virgo Collaboration.
The event occurred at GPS time 1186741861.53 = August 14 2017, 10:30:43.53 UTC.
The event was detected in data from the LIGO Hanford (H1), LIGO Livingston (L1) and Virgo (V1) detectors.
This page serves as a supplement to the paper GW170814 : A three-detector observation of gravitational waves from a binary black hole coalescence, available from doi:10.1103/PhysRevLett.119.141101.
- This dataset has DOI doi:10.7935/K5MP519B.
- The GW170814 discovery paper science summary gives an overview of the event.
- The one page factsheet about GW170814 lists statistics.
- The technical details page describes details of the data set.
- Please contact us with any questions.
Gravitational-Wave Strain Data
- Data usage notes: Please Read This First!
- The data are provided in three formats. HDF5 , Frame (.gwf), and gzipped ascii text. Many data analysis environments can read in data from HDF5 files, including Python (see the h5py package), MATLAB, C/C++, and IDL.
- Virgo data are noisier at frequencies above 2 kHz (See technical details).
- LIGO data are only calibrated from 10-5000 Hz (Data usage notes)
- Tutorials provide an introduction to strain data.
- Software libraries are available for data analysis.
Strain data after noise subtraction
Several noise sources that are linearly coupled to the GW data channel can be subtracted in post-processing, using auxiliary sensors (e.g. photodiodes monitoring beam motion). For LIGO, we remove calibration lines, power mains and harmonics, the effect of some length and angular controls, and the effect of laser beam motion. This noise removal can improve the sensitivity of the LIGO detectors by approximately 20%. For Virgo, we remove the effect of some length controls, and the laser frequency stabilization control. For reference:
- Improving astrophysical parameter estimation via post-processing noise subtraction for Advanced LIGO
- GW170814 : A three-detector observation of gravitational waves from a binary black hole coalescence
Notes:
- Below are links to strain h(t) time series centered at GPS 1186741861.
- The noise subtraction procedure applies a window which tapers the first and last few minutes of the H1 and L1 data files. To remove this corrupt data, the H1 and L1 cleaned data files have been shortened to a total duration of 3584 seconds.
- The H1 and L1 noise subtraction procedure introduces excess noise at frequencies below 20 Hz. Users should restrict analysis to frequencies above 20 Hz.
- The files and some technical notes may all be found in LIGO P1700341
- md5 checksums may be used to ensure files are correctly downloaded.
| After noise subtraction, 4096 Hz | H1 | L1 | V1 |
|---|---|---|---|
| 32 seconds (event signal reaches peak amplitude 16.53 seconds ± 30 msec from start†) | hdf5 gwf txt.gz | hdf5 gwf txt.gz | hdf5 gwf txt.gz |
| 3584 or 4096 seconds‡ | hdf5 gwf txt.gz | hdf5 gwf txt.gz | hdf5 gwf txt.gz |
| After noise subtraction, 16384 Hz | H1 | L1 | V1 |
|---|---|---|---|
| 32 seconds (event signal reaches peak amplitude 16.53 seconds ± 30 msec from start†) | hdf5 gwf txt.gz | hdf5 gwf txt.gz | hdf5 gwf txt.gz |
| 3584 or 4096 seconds‡ | hdf5 gwf txt.gz | hdf5 gwf txt.gz | hdf5 gwf txt.gz |
† The ± 30 msec window for peak amplitude is due to different arrival times in each of the three detectors.
‡ The H1, L1 datasets for strain data after noise subtraction are 3584 seconds long with the event signal reaching peak amplitude 1792.53 seconds ± 30 msec from start†. The V1 data files are 4096 seconds long, with the signal reaching peak amplitude 2048.53 ± 30 ms from the start of the file.
Strain data before noise subtraction
These files contain data before noise subtraction. These data were produced in low-latency, and used by the search pipelines to evaluate event significance.
Notes:
- Below are links to strain h(t) time series centered at GPS 1186741861.
- Data are typically noisy and unreliable at frequencies below 20 Hz.
- The files and some technical notes may all be found in LIGO P1700340
- md5 checksums may be used to ensure files are correctly downloaded.
| Before noise subtraction, 4096 Hz | H1 | L1 | V1 |
|---|---|---|---|
| 32 seconds (event signal reaches peak amplitude 16.53 seconds ± 30 msec from start†) | hdf5 gwf txt.gz | hdf5 gwf txt.gz | hdf5 gwf txt.gz |
| 4096 seconds (event signal reaches peak amplitude 2048.53 seconds ± 30 msec from start†) | hdf5 gwf txt.gz | hdf5 gwf txt.gz | hdf5 gwf txt.gz |
| Before noise subtraction, 16384 Hz | H1 | L1 | V1 |
|---|---|---|---|
| 32 seconds (event signal reaches peak amplitude 16.53 seconds ± 30 msec from start†) | hdf5 gwf txt.gz | hdf5 gwf txt.gz | hdf5 gwf txt.gz |
| 4096 seconds(event signal reaches peak amplitude 2048.53 seconds ± 30 msec from start†) | hdf5 gwf txt.gz | hdf5 gwf txt.gz | hdf5 gwf txt.gz |
† The ± 30 msec window for peak amplitude is due to different arrival times in each of the three detectors.
Sky Localization
Source localization data for GW170814 are available as LIGO T1700453
Rapid triggers from LIGO data are available as GCN notices for GW170814
- A python library for reading the FITS DATA is healpy.
- See example code to work with source localization data
- Collections of simulated skymaps are available here and here.
See the About the Detectors Page to learn about the instruments and collaborations.
The technical details provides detailed usage notes.
Feel free to contact us with any questions.