Data release for event GW170104
This page has been prepared by the LIGO Scientific Collaboration (LSC) and the Virgo Collaboration to inform the broader community about a confirmed astrophysical event observed by the gravitational-wave detectors, and to make the data around that time available for others to analyze.
GW170104 was observed at GPS time 1167559936.6 == January 04 2017, 10:11:58.6 UTC. It was recovered with a network signal-to-noise ratio of 13 and a false-alarm-rate of once per 70,000 years. The event was detected in data from the LIGO Hanford and LIGO Livingston observatories.
This page serves as a supplement to the paper GW170104: Observation of a 50-solar-mass binary black hole coalescence at redshift 0.2 which is available from LIGO DCC.
- There are more open data about this event, in the files attached to the above paper in the LIGO DCC.
- There are Science Summaries, covering the information below in ordinary language.
- This dataset has the Digital Object Identifier (doi) https://doi.org/10.7935/K53X84K2
- There are tutorials to work with the strain data.
- There is a one page factsheet about GW170104, summarizing the event.
- There is a technical details page about the data linked below, and feel free to contact us.
Estimated Source Parameters
| Quantity | Value | Unit |
|---|---|---|
| UTC time | 2017-01-04T10:11:58.6 | |
| GPS time | 1167559936.6 | |
| Primary mass | 31.2 +8.4 -6.0 | Msun |
| Secondary mass | 19.4 +5.3 -5.9 | Msun |
| Chirp mass | 21.1 +2.4 -2.7 | Msun |
| Total mass | 50.7 +5.9 -5.0 | Msun |
| Final mass | 48.7 +5.7 -4.6 | Msun |
| Radiated energy | 2.0 +0.6 -0.7 | Msun c^2 |
| Peak luminosity | 3.1 +0.7 -1.3 | 10^56 erg s^-1 |
| Effective inspiral spin | -0.12 +0.21 -0.30 | |
| Final spin | 0.64 +0.09 -0.20 | |
| Luminosity distance | 880 +450 -390 | Mpc |
| Source redshift | 0.18 +0.08 -0.07 | |
| False alarm rate | < 1.4e-05 | yr^-1 |
| Signal to Noise Ratio | 13 | |
| Sky localization | 1200 | deg^2 |
The data from the observatories from which the science is derived:
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.
- The md5 checksums provide a check for downloaders that they have received the right file: run the Unix command "md5" (or "md5sum", depending on your OS) on your file and compare to LOSC published values. If different, try downloading again, and if the problem persists, contact us.
- Technical details especially about data quality and injections
- Tutorials to work with the strain data.
Strain Data at 4096 Hz
Strain h(t) time series centered at GPS 1167559936.
| Hanford | Livingston | |
|---|---|---|
| 32 seconds (event is 16.60 seconds from start) | hdf5 gwf txt.gz | hdf5 gwf txt.gz |
| 4096 seconds (event is 2048.60 seconds from start) | hdf5 gwf txt.gz | hdf5 gwf txt.gz |
Strain Data at 16384 Hz
Strain h(t) time series centered at GPS 1167559936.
| Hanford | Livingston | |
|---|---|---|
| 32 seconds (event is 16.60 seconds from start) | hdf5 gwf txt.gz | hdf5 gwf txt.gz |
| 4096 seconds (event is 2048.60 seconds from start) | hdf5 gwf txt.gz | hdf5 gwf txt.gz |
Sky Localization
The location of GW170104 in the sky can be determined only roughly using the data from the two gravitational-wave detectors. A "skymap", representing the position probability as a function of astronomical sky coordinates (right ascension and declination), was initially computed by a software package called BAYESTAR. After final calibration of the data, the skymap was recomputed with a more sophisticated package called LALInference which simultaneously adjusts all the source parameters and allows for calibration uncertainties.
Visualize the source sky localization estimated from LIGO and Virgo observations.
Low-latency (rapid) skymap from BAYESTAR:
Refined skymap from LALInference:
A python library for reading the FITS DATA 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.
About the Instruments and Collaborations
See the instruments and collaborations page.
There is a technical details page about the data linked above, and feel free to contact us.
Revision History
- July 26, 2017: Added link to factsheet.