Published November 20, 2023 | Version v1
Dataset Open

An Anti-halo Void Catalogue of the Local Super-Volume

  • 1. Stockholm University
  • 2. University College London
  • 3. CNRS Délégation Paris Centre


Data from the construction of an anti-halo void catalogue of the Local Super-Volume. This upload contains the full anti-halo catalogue (also included in the associated publication) as well as the individual anti-halo catalogues for each resimulated posterior sample. We also include anti-halo catalogues from the 20 independent random simulations used in the associated paper for constructing the filters and comparing to Lambda-CDM.

The catalogue is provided in both comma separated values (csv) and numpy (npz) formats. For high precision work, npz should be preferred.

Technical info


There are three main csv files for the combined catalogue:


This file lists the anti-halos in each MCMC sample corresponding to the 150 voids within 135 Mpc/h of the Milky way, after applying filtering on reproducibility score. The column headers indicate MCMC sample an anti-halo belongs to. Each entry is the numerical index of the anti-halo in the relevant MCMC anti-halo catalogue (NB -  the indices start from 1 as the first entry in the catalogue: subtract 1 to obtain a numpy or c-style index). Entries of -1 indicate that no anti-halo satisfying the conditions to be a counterpart in that MCMC sample was found.


This file lists the properties of the 150 voids in the combined catalogue, corresponding to table A1 of the associated paper. We also include some additional properties not listed in table A1, including the mean central (within R/4 of the void centre) and average (mass/volume) density contrasts of the voids and the uncertainties as standard error of these means. The first row identifies each property.


  1. ID of halo in the combined catalogue.
  2. Radius in Mpc/h
  3. Radius error, in Mpc/h
  4. Mass in 10^14 Msol/h
  5. Mass error in 10^14 Msol/h
  6. Right ascension, in degrees
  7. Declination, in degrees
  8. Redshift
  9. Distance, in Mpc/h
  10. Signal to noise ratio (average of \delta^2/\sigma_{\delta}^2)
  11. Reproducibility Score
  12. Central density contrast (within R/4 of void centre)
  13. Central density contrast error
  14. Average density contrast (mass/volume for void)
  15. Average density contrast error.


This file lists the unfiltered output of the void combination algorithm, before applying cuts on distance from the Milky Way (to 135 Mpc/h), mass, radius, and reproducibility score. The vast majority of the voids here are of too-low reproducibility score to be distinguished from noise, but we include them for completeness. Format is the same as combined_catalogue.csv

mcmc_catalogue_csv.tar.gz and random_catalogues_csv.tar.gz:

The anti-halo catalogues for each MCMC sample are provided in the mcmc_catalogue_csv.tar.gz. The indices in combined_catalogue.csv and combined_catalogue_unfiltered.csv refer to the entries in these catalogues for each sample respectively. The rows list the properties of each void in the catalogue, with the first row identifying the properties in each column. Note - due to resolution limits, a minority of voids do not have a well-defined central density (recorded as nan); usually this is because they have been partially flattened into a Zel'dovich pancake by an ongoing collapse. The catalogues have been truncated to include all voids above 5 Mpc/h and within 300 Mpc/h of the Milky Way whose signal-to-noise (\delta^2/\sigma_{\delta}^2) is above 10.

Positions of the anti-halos are given in Cartesian Equatorial co-ordindates as the columns X, Y, Z, with units of Mpc/h. These can be straightforwardly converted to Right Ascension, Declination, and Distance in the standard manner.

We also provide analogous catalogues from a set of 20 random simulations with identical setup to the posterior resimulations. These are given in the random_catalogues_csv.tar.gz file.

Columns for anti-halo catalogues:

  1. ID of halo within this MCMC sample
  2. Radius in Mpc/h
  3. Mass in Msol/h
  4. X position in Equatorial cartesian co-ordinates, units of Mpc/h
  5. Y position in Equatorial cartesian co-ordinates, units of Mpc/h
  6. Z position in Equatorial cartesian co-ordinates, units of Mpc/h
  7. Distance in Mpc/h
  8. Central density contrast (within R/4 of void centre)
  9. Average density contrast (mass/volume)
  10. Signal-to-noise ratio (average of \delta^2/\sigma_{\delta}^2)


The npz files contain the same data as the csv files, but with more structure for convenient importation into python. The floating point precision of the data here is also higher.

There are two main files:


   This file contains the combined catalogue as in combined_catalogue.csv, as an array, and additionally contains the properties of the catalogue. The fields are are follows:

  • file['catalogue'] - The combined catalogue. Same format as combined_catalogue.csv
  • file['radii'] - Mean void radii of the voids in the catalogue.
  • file['radii_error'] - Standard error of the mean radii.
  • file['mass'] - Mean void mass of the voids in the catalogue
  • file['mass_error'] - Standard error of the mean mass.
  • file['ra'] - Right Ascension of the void's mean centre.
  • file['dec'] - Declination of the void's mean centre
  • file['dist'] - Distance to the void's mean centre, in Mpc/h
  • file['snr'] - Signal to noise ratio of the void, obtained by averaging \delta^2/\sigma_{\delta}^2 over the void's voxels.
  • file['rep_score'] - Reproducibility score of the void, giving an indication of how well-constrained the void is.
  • file['delta_central'] - Mean of the central density contrast (defined as the cumulative density contrast within R/4, where R is the void radius) over all mcmc samples.
  • file['delta_central_error'] - Standard error of the mean central density.
  • file['delta_average'] - Mean of the average density contrast (defined as mass/volume for a void) over all mcmc samples.
  • file['delta_average_error'] - Standard error of the average density contrast


This file contains only a single field (['catalogue']) which contains the unfiltered catalogue as a numpy array, as in combined_catalogue.csv.

mcmc_catalogues_npz.tar.gz and random_catalogues_npz.tar.gz:

The tar archives mcmc_catalogues_npz.tar.gz and random_catalogues_npz.tar.gz contain the numpy array versions of the counterparts in the csv folder. Fields are as follows in each file:

  • file['radii'] - Radius of the anti-halo
  • file['mass'] - Mass of the anti-halo
  • file['centre'] - Centre of the anti-halo, [x,y,z], in Cartesian Equatorial co-ordinates.
  • file['dist'] - Distance to the anti-halo from the Milky Way, in Mpc/h.
  • file['delta_central'] - Central density contrast of the anti-halo.
  • file['delta_average'] - Average density contrast of the anti-halo.
  • file['snr'] - Signal to noise ratio of the anti-halo.
  • file['ids'] - Index of the anti-halo in the catalogue, starting from 1.







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Additional details

Related works

Is described by
Preprint: arXiv:2311.12926 (arXiv)