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VST ATLAS galaxy cluster catalogue I: cluster detection and mass calibration

Ansarinejad, Behzad; Murphy, David; Shanks, Tom; Metcalfe, Nigel

VST ATLAS galaxy cluster catalogue I: cluster detection and mass calibration Thumbnail


Behzad Ansarinejad

David Murphy

Tom Shanks


Taking advantage of ∼4700 deg2 optical coverage of the Southern sky offered by the VST ATLAS survey, we construct a new catalogue of photometrically selected galaxy groups and clusters using the ORCA cluster detection algorithm. The catalogue contains ∼22 000 detections with N200 > 10 and ∼9000 with N200 > 20. We estimate the photometric redshifts of the clusters using machine learning and find the redshift distribution of the sample to extend to z ∼ 0.7, peaking at z ∼ 0.25. We calibrate the ATLAS cluster mass-richness scaling relation using masses from the MCXC, Planck, ACT DR5, and SDSS redMaPPer cluster samples. We estimate the ATLAS sample to be >95 per cent complete and >85 per cent pure at z < 0.35 and in the M200m>1×1014h−1M⊙ mass range. At z < 0.35, we also find the ATLAS sample to be more complete than redMaPPer, recovering a ∼40 per cent higher fraction of Abell clusters. This higher sample completeness places the amplitude of the z < 0.35 ATLAS cluster mass function closer to the predictions of a ΛCDM model with parameters based on the Planck CMB analyses, compared to the mass functions of the other cluster samples. However, strong tensions between the observed ATLAS mass functions and models remain. We shall present a detailed cosmological analysis of the ATLAS cluster mass functions in paper II. In the future, optical counterparts to X-ray-detected eROSITA clusters can be identified using the ATLAS sample. The catalogue is also well suited for auxiliary spectroscopic target selection in 4MOST. The ATLAS cluster catalogue is publicly available at


Ansarinejad, B., Murphy, D., Shanks, T., & Metcalfe, N. (2023). VST ATLAS galaxy cluster catalogue I: cluster detection and mass calibration. Monthly Notices of the Royal Astronomical Society, 520(1), 1371-1389.

Journal Article Type Article
Acceptance Date Dec 22, 2022
Online Publication Date Jan 31, 2023
Publication Date 2023-03
Deposit Date May 31, 2023
Publicly Available Date Jun 2, 2023
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 520
Issue 1
Pages 1371-1389
Public URL


Published Journal Article (3 Mb)

Copyright Statement
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2023 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

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