Data release for GW240925 and GW250207: Astrophysical Calibration of Gravitational-wave Detectors

This data release accompanies the publication "GW240925 and GW250207: Astrophysical calibration of gravitational wave detectors." We provide analysis results and plotting notebooks that demonstrate how to reproduce the publication plots using the analysis data. In general, each analysis is zipped into its own tar file, which includes multiple result files.

Notebooks

In the notebooks.tar.gz are five notebooks that demonstrate how to use the data described below to reproduce plots like those in the paper:

• calibration-monitoring.ipynb: Figs. 5–7
• inference-results.ipynb: uses cal_env.tar.gz and combined_samples.tar.gz to make Figs. 2, 8–9
• parametrized-tests.ipynb: uses qnmrf.tar.gz, pca.tar.gz, fti.tar.gz, pseobnr.tar.gz, tiger.tar.gz, ringdown.tar.gz, and combined_samples.tar.gz to make Figs. 4, 14–15
• sky-localizations.ipynb: uses skymaps.tar.gz and combined_samples.tar.gz to make Figs. 3, 10–12
• spectrograms.ipynb: uses residuals.tar.gz, GW240925-C00-Strain.tar, and strain data downloaded from GWOSC to make Figs. 1, 13

Here, we number figures as they appear in the arXiv version, which combines the main paper (Figs. 1–4) and the Supplemental Material (Figs. 5–13).

The notebooks use standard Python packages as well as specialist packages including astropy, GWpy, ligo.skymap, Bilby and PESummary. A lightweight Python environment similar to those used for the Open Data Workshops should work.

Parameter estimation results

For users interested only in the preferred parameter estimation posteriors for each event, those are uploaded separately as:

• GW250207_combinedPHM_cal_metafile.hdf5
• GW240925_combinedPHM_envcalC01_metafile.hdf5

As described in the paper, each event was analyzed using multiple analysis choices for the input data and calibration correction. All analyses (include the two highlighted above) are zipped into the combined_samples.tar.gz file, where the filename indicates the data and calibration correction type for that analysis (i.e., combinedPHM_envcalC01_metafile.hdf5 refers to the analysis of the C01 data using the in-situ calibration envelope). These are PESummary metafiles that include the results of all the analyses performed with different waveform models for the choice of data and calibration correction given in the name of the file, along with the mixed samples that include an equal number of samples generated with each waveform, including both precession and higher-order modes.

Strain data

While strain data for the preferred analyses highlighted above can be downloaded from GWOSC (GW240925, GW250207), the file GW240925-C00-Strain.tar contains the miscalibrated C00 data for GW240925, which were analyzed in the paper. This tarfile contains various strain data files, broken down into directories based on                                                                            

(a) sample rate (4KHZ vs 16KHZ, i.e., 4096 samples per second and 16384 samples per second)                                                                  

(b) file type, i.e., extension GWF for gravitational-wave frame files and HDF for HDF5 files                                                                                    

(c) The detector the strain represents, i.e., H1, L1 and V1 for Hanford, Livingston and Virgo

(d) There is an md5 subdirectory for each sampling rate that contains two files, one for GWF files and one for HDF files with the md5sum value for each detector

Calibration envelope input files for parameter estimation

The cal_env.tar.gz file contains input files used to configure the analyses to infer the source parameters. Specifically, these are the files that are used to construct the prior on calibration parameters for the Hanford detector. The same inputs are used for various analyses.

• calibration_uncertainty_H1_tmp_20.txt contains the wide, uninformative calibration prior. This prior was used for analysis of GW240925 and GW250207.
• The directory S240925n contains the calibration priors based upon in-situ measurements of the detector for GW240925.                                                      
  • The subdirectory C00 contains the in-situ prior for the miscalibrated C00 version of the data.                                                                            
  • The subdirectory C01 contains the in-situ prior for the recalibrated C01 version of the data.                                                                             

In both cases, the input file for S240925n is named calibration_uncertainty_H1_1411261218.txt. There is no in-situ prior for GW250207. The inputs for each analysis can also be found in the results files in the combined_samples directory. These can be cross-referenced to check what was used for each analysis.

Parameter estimation skymaps

In the skymaps.tar.gz file, we include fits files for the skymaps corresponding to each parameter estimation analysis. In addition to the Mixed-waveform results (i.e., S240925n/combinedPHM_envcalC00_skymap.fits) and the individual-waveform results (i.e., S250207bg/NRSur7dq4_H1cal_skymap.fits), we also include the low-latency Bayestar and Bilby skymaps that were generated in the online analyses of both events plotted in Figs. 3 and 11 in the paper, which can also be downloaded from the GraceDB pages for each event (S250207bg, S240925b).

Residuals

The file residuals.tar.gz contains the residual frames for the GW240925 and GW250207 events. The directories for each event contain frame files made using either the flat, wide prior (flat_wide_calib) inferred calibration or without inferring calibration (no_calib). The channel names for the residuals frames are 

{H1:GDS-CALIB_STRAIN_CLEAN_RES, L1:GDS-CALIB_STRAIN_CLEAN_AR_RES, V1:Hrec_hoftRepro1AR_16384Hz_RES}      

FTI

The file fti.tar.gz contains the analysis results for searches for parameterized deviations from general relativity using the Flexible Theory-Independent framework. The sub-directories are divided based on the event and the calibration correction assumed during the analysis:

• S240925n_correct_cal (C00 envelopes)
• S240925n_no_cal
• S240925n_wide_cal
• S250207bg_no_cal
• S250207bg_wide_cal

All analyses of S240925n are performed using the C00 data. Within these directories, the filenames specify which parameter is allowed to deviate from its GR value, i.e., fti_dchi5lNS.h5.

TIGER 

The file tiger.tar.gz contains posterior samples from TIGER (Test Infrastructure for GEneral Relativity) analyses of the gravitational-wave events GW240925 and GW250207. The repository is organized into the following directories:

• GW240925_cal/ Analysis of GW240925 including calibration uncertainty  
• GW240925_no_cal/ Analysis of GW240925 without calibration uncertainty  
• GW250207_cal/ Analysis of GW250207 including calibration uncertainty  
• GW250207_no_cal/ Analysis of GW250207 without calibration uncertainty  

Each directory contains 18 posterior sample files corresponding to different parameterized-deviation analyses. The TIGER analyses are divided into two categories:

1. Inspiral (PN) Deviations: Parameterized deviations introduced in the post-Newtonian (PN) phase coefficients. Files ending with:

• dchi_minus2.h5: −1 PN deviation  
• dchi_0.h5: 0 PN deviation  
• dchi_1.h5: 0.5 PN deviation  
• dchi_2.h5: 1 PN deviation  
• dchi_3.h5: 1.5 PN deviation  
• dchi_4.h5: 2 PN deviation  
• dchi_5l.h5: 2.5 PN logarithmic deviation  
• dchi_6.h5: 3 PN deviation  
• dchi_6l.h5: 3.5 PN logarithmic deviation  
• dchi_7.h5: 3.5 PN deviation  

2. Post-Inspiral Deviations: Parameterized deviations introduced in the phenomenological coefficients of the IMRPhenomXAS waveform model.

Intermediate regime

• db_1.h5: deviation in coefficient $b_1$
• db_2.h5: deviation in coefficient $b_2$  
• db_3.h5: deviation in coefficient $b_3$  
• db_4.h5: deviation in coefficient $b_4$  

Merger-Ringdown regime

• dc_1.h5: deviation in coefficient $c_1$  
• dc_2.h5: deviation in coefficient $c_2$  
• dc_4.h5: deviation in coefficient $c_4$  
• dc_l.h5: deviation in coefficient $c_\ell$

Parametrized tests of post-Newtonian theory using Principal Component Analysis (PCA)

The file pca.tar.gz contains the following files with the results of the PCA analyses for both events:

• pca_tiger_GW250207_115645_C00_none_dchi_3_dchi_4_dchi_5l_dchi_6_dchi_6l_dchi_7.h5 is the PESummary-format file containing PCA analysis results within the TIGER framework for the event GW250207_115645 with C00_none calibration.
• pca_fti_GW250207_115645_C00_none_dchi_3NS_dchi_4NS_dchi_5lNS_dchi_6NS_dchi_6l_dchi_7NS.h5 is the PESummary-format file containing PCA analysis results within the FTI framework for the event GW250207_115645 with C00_none calibration.
• pca_tiger_GW250207_115645_C00_wide_dchi_3_dchi_4_dchi_5l_dchi_6_dchi_6l_dchi_7.h5 is the PESummary-format file containing PCA analysis results within the TIGER framework for the event GW250207_115645 with C00_wide calibration.
• pca_fti_GW250207_115645_C00_wide_dchi_3NS_dchi_4NS_dchi_5lNS_dchi_6NS_dchi_6l_dchi_7NS.h5 is the PESummary-format file containing PCA analysis results within the FTI framework for the event GW250207_115645 with C00_wide calibration.
• pca_tiger_GW240925_005809_C00_none_dchi_3_dchi_4_dchi_5l_dchi_6_dchi_6l_dchi_7.h5 is the PESummary-format file containing PCA analysis results within the TIGER framework for the event GW240925_005809 with C00_none calibration.
• pca_tiger_GW240925_005809_C00_wide_dchi_3_dchi_4_dchi_5l_dchi_6_dchi_6l_dchi_7.h5 is the PESummary-format file containing PCA analysis results within the TIGER framework for the event GW240925_005809 with C00_wide calibration.
• pca_tiger_GW240925_005809_C00_envelope_dchi_3_dchi_4_dchi_5l_dchi_6_dchi_6l_dchi_7.h5 is the PESummary-format file containing PCA analysis results within the TIGER framework for the event GW240925_005809 with C00_envelope calibration.
• pca_tiger_GW240925_005809_C01_envelope_dchi_3_dchi_4_dchi_5l_dchi_6_dchi_6l_dchi_7.h5 is the PESummary-format file containing PCA analysis results within the TIGER framework for the event GW240925_005809 with C01_envelope calibration.

pSEOBNR

The file pseobnr.tar.gz contains the results of the pSEOBNR ringdown analysis:

• 22_NoCal.hdf5: Posterior samples of the pSEOBNR analysis that allows for parametrized deviations to the (2,2,0) quasinormal mode, with no calibration.
• 22_WideCal.hdf5: Posterior samples of the pSEOBNR analysis that allows for parametrized deviations to the (2,2,0) quasinormal mode, with wide calibration.
• 22_NoCal_ftau.h5: Frequency and damping time of the (2,2,0) quasinormal mode calculated from the samples from the analysis with no calibration uncertainty.
• 22_WideCal_ftau.h5: Frequency and damping time of the (2,2,0) quasinormal mode calculated from the samples from the analysis with wide calibration uncertainty.
• 22_44_NoCal.hdf5: Posterior samples of the pSEOBNR analysis that allows for parametrized deviations to the (2,2,0) and (4,4,0) quasinormal modes, with no calibration.
• 22_44_WideCal.hdf5: Posterior samples of the pSEOBNR analysis that allows for parametrized deviations to the (2,2,0) and (4,4,0) quasinormal modes, with wide calibration.

Ringdown

The file ringdown.tar.gz contains the following files with the results of the Ringdown pipeline analysis for GW250207. Details on how to read and work with these file formats can be found in the linked documentation.

• Raw .nc files containing full posteriors from fits to the H1 and L1 data separately with the Kerr 220 model starting at $8 t_{M_\mathrm{f}}$ after the peak.               
• An .hdf5 file containing full posteriors on specific parameters m, chi, f, g (remnant final mass, remnant final spin, 220 frequency, 220 damping rate, respectively).       

Quasinormal mode rational filter (QNMRF)

The file qnmrf.tar.gz contains the following files needed to reproduce the QNMRF contours shown in Fig. 4:

• QNMRF_GW250207_Hanford_220_t=8.0M.h5 contains the results from the Hanford-only analysis with an analysis start time of $8 t_{M_\mathrm{f}}$, considering only the 220 QNM. This file contains a grid of likelihood values corresponding to values of mass and spin.
• QNMRF_GW250207_Livingston_220_t=8.0M.h5 contains the results from the Livingston-only analysis with an analysis start time of $8 t_{M_\mathrm{f}}$, considering only the 220 QNM. This file contains a grid of likelihood values corresponding to values of mass and spin.
• QNMRF_mass_chi_grid.npz contains the grid of mass-spin values the likelihood values above refer to. 
• f_tau_credible_contours_evo_8.0M.npz directly contains the contour information from the Hanford-only and Livingston-only analyses with a start time of $8 t_{M_\mathrm{f}}$, considering only the 220 QNM. 

Further analysis details and examples for how to work with these data files are available in the QNMRF documentation.