Skip to main content

Research Repository

Advanced Search

The local hole: a galaxy underdensity covering 90 per cent of sky to ≈200 Mpc

Wong, Jonathan HW; Shanks, T; Metcalfe, N; Whitbourn, JR

The local hole: a galaxy underdensity covering 90 per cent of sky to ≈200 Mpc Thumbnail


Jonathan HW Wong

T Shanks

JR Whitbourn


We investigate the ‘Local Hole’, an anomalous underdensity in the local galaxy environment, by extending our previous galaxy K-band number-redshift and number-magnitude counts to ≈90 per cent of the sky. Our redshift samples are taken from the 2MASS Redshift Survey (2MRS) and the 2M++ catalogues, limited to K < 11.5. We find that both surveys are in good agreement, showing an ≈21−22 per cent underdensity at z < 0.075 when compared to our homogeneous counts model that assumes the same luminosity function (LF) and other parameters as in our earlier papers. Using the Two Micron All Sky Survey (2MASS) for n(K) galaxy counts, we measure an underdensity relative to this model of 20±2 per cent at K < 11.5, which is consistent in both form and scale with the observed n(z) underdensity. To examine further the accuracy of the counts model, we compare its prediction for the fainter n(K) counts of the Galaxy and Mass Assembly (GAMA) survey. We further compare these data with a model assuming the parameters of a previous study where little evidence for the Local Hole was found. At 13 < K < 16, we find a significantly better fit for our galaxy counts model, arguing for our higher LF normalization. Although our implied underdensity of ≈20 per cent means local measurements of the Hubble Constant have been overestimated by ≈3 per cent, such a scale of underdensity is in tension with a global ΛCDM cosmology at an ≈3σ level.


Wong, J. H., Shanks, T., Metcalfe, N., & Whitbourn, J. (2022). The local hole: a galaxy underdensity covering 90 per cent of sky to ≈200 Mpc. Monthly Notices of the Royal Astronomical Society, 511(4), 5742-5755.

Journal Article Type Article
Acceptance Date Feb 7, 2022
Online Publication Date Mar 2, 2022
Publication Date 2022-04
Deposit Date May 26, 2022
Publicly Available Date May 26, 2022
Journal Monthly Notices of the Royal Astronomical Society
Print ISSN 0035-8711
Electronic ISSN 1365-2966
Publisher Royal Astronomical Society
Peer Reviewed Peer Reviewed
Volume 511
Issue 4
Pages 5742-5755


Published Journal Article (1.8 Mb)

Copyright Statement
This article has been accepted for publication in Monthly notices of the Royal Astronomical Society. &copy;: 2021 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

You might also like

Downloadable Citations