Data release for event GW170608
This page has been prepared by the LIGO Scientific Collaboration (LSC) and the Virgo Collaboration.
The event occurred at GPS time 1180922494.49 = June 08 2017, 02:01:16.49 UTC.
The event was observed by data from the LIGO Hanford (H1) and LIGO Livingston (L1) detectors.
Note: Virgo joined the O2 observing run on August 1st, 2017. At the time of the event the Advanced Virgo detector was in a commissioning phase in preparation for the O2 science run. The detector was operating with limited sensitivity. No fully characterized strain data from Virgo is available for this event
- This page serves as a supplement to the paper GW170608: Observation of a 19-Solar-Mass Binary Black Hole Coalescence, available from LIGO DCC and doi:10.3847/2041-8213/aa9f0c.
- This dataset has DOI doi:10.7935/K51R6NJQ.
- The GW170608 science summary gives an overview of the event.
- The one page factsheet lists statistics.
- The technical details page describes details of the data set.
- 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.
- Tutorials provide an introduction to strain data.
- Software libraries are available for data analysis.
Strain data after noise subtraction
After data collection, several independently-measured terrestrial contributions to the detector noise were subtracted from the LIGO data using Wiener filtering. This subtraction removed calibration lines and 60 Hz AC power mains harmonics from both LIGO data streams. At times near GW170608, the sensitivity of LIGO-Hanford was particularly improved by the subtraction of laser pointing noise; several broad peaks in the 150 - 800 Hz region were effectively removed, increasing the Binary Neutron Star horizon distance of that detector by typically 25%. For reference:
- Improving astrophysical parameter estimation via post-processing noise subtraction for Advanced LIGO
- GW170608: Observation of a 19-Solar-Mass Binary Black Hole Coalescence
Notes:
- Below are links to strain h(t) time series centered at GPS 1180922494.
- All cleaned data files have been shortened to a total duration of 512 and 32 seconds.
- The H1 and L1 noise subtraction procedure introduces excess noise at frequencies below 20 Hz.
- The H1 data has excess noise at frequencies below 30 Hz due to a routine instrumental activity to minimize angular control couplings.
- Users should restrict analysis to frequencies above 20 Hz for L1 and should restrict analysis for H1 to frequences above 30 Hz
- The files and some technical notes may all be found in LIGO P1700375
- md5 checksums may be used to ensure files are correctly downloaded.
Strain Data at 4096 Hz
Strain h(t) time series centered at GPS 1180922494.
| H1 | L1 | |
|---|---|---|
| 32 seconds (event signal reaches peak amplitude 16.49 seconds ± 10 msec from start†) | hdf5 gwf txt.gz | hdf5 gwf txt.gz |
| 512 seconds (event signal reaches peak amplitude 256.49 seconds ± 10 msec from start†) | hdf5 gwf txt.gz | hdf5 gwf txt.gz |
Strain Data at 16384 Hz
Strain h(t) time series centered at GPS 1180922494.
| H1 | L1 | |
|---|---|---|
| 32 seconds (event signal reaches peak amplitude 16.49 seconds ± 10 msec from start†) | hdf5 gwf txt.gz | hdf5 gwf txt.gz |
| 512 seconds (event signal reaches peak amplitude 256.49 seconds ± 10 msec from start†) | hdf5 gwf txt.gz | hdf5 gwf txt.gz |
† The ± 10 msec window for peak amplitude is due to different arrival time in each of the LIGO detectors.
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 1180922494.
- The last 7 seconds of the H1 4096 second long files in the tables below contain NaN in the place of strain values due to the detector not being in a nominal locked state for data analysis.
- The H1 data has excess noise at frequencies below 30 Hz due to routine instrumental activity to minimize angular control couplings. Users should restrict analysis to frequencies above 20 Hz for L1 and should restrict analysis for H1 to frequences above 30 Hz.
- The files and some technical notes may all be found in LIGO P1700413
- md5 checksums may be used to ensure files are correctly downloaded.
Strain Data at 4096 Hz
Strain h(t) time series centered at GPS 1180922494.
| H1 | L1 | |
|---|---|---|
| 32 seconds(event signal reaches peak amplitude 16.49 seconds ± 10 msec from start†) | hdf5 gwf txt.gz | hdf5 gwf txt.gz |
| 4096 seconds(event signal reaches peak amplitude 2048.49 seconds ± 10 msec from start†) | hdf5 gwf txt.gz | hdf5 gwf txt.gz |
Strain Data at 16384 Hz
Strain h(t) time series centered at GPS 1180922494.
| H1 | L1 | |
|---|---|---|
| 32 seconds (event signal reaches peak amplitude 16.49 seconds ± 10 msec from start†) | hdf5 gwf txt.gz | hdf5 gwf txt.gz |
| 4096 seconds (event signal reaches peak amplitude 2048.49 seconds ± 10 msec from start†) | hdf5 gwf txt.gz | hdf5 gwf txt.gz |
† The ± 10 msec window for peak amplitude is due to different arrival time in each of the LIGO detectors.
Sky Localization
Source localization data for GW170608 are available as LIGO G1702263
Rapid triggers from LIGO data are available as GCN notices for GW170608
- 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.