Galaxy cluster mass reconstruction project - II: quantifying scatter and bias using contrasting mock catalogues

Old, Lyndsay and Wojtak, R. and Mamon, G.A. and Skibba, R.A. and Pearce, Frazer R. and Croton, D. and Bamford, Steven P. and Behroozi, Peter and Carvalho, R. de and Muñoz-Cuartas, J.C. and Gifford, D. and Gray, M.E. and Linden, A. von der and Merrifield, M. and Muldrew, S.I. and Müller, V. and Pearson, R.J. and Ponman, T.J. and Rozo, E. and Rykoff, E. and Saro, Alexandro and Sepp, T. and Sifón, C. and Tempel, E. (2015) Galaxy cluster mass reconstruction project - II: quantifying scatter and bias using contrasting mock catalogues. Monthly Notices of the Royal Astronomical Society, 449 (2). pp. 1897-1920. ISSN 1365-2966

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Abstract

This paper is the second in a series in which we perform an extensive comparison of various galaxy-based cluster mass estimation techniques that utilize the positions, velocities and colours of galaxies. Our aim is to quantify the scatter, systematic bias and completeness of cluster masses derived from a diverse set of 25 galaxy-based methods using two contrasting mock galaxy catalogues based on a sophisticated halo occupation model and a semi-analytic model. Analysing 968 clusters, we find a wide range in the rms errors in log M200c delivered by the different methods (0.18–1.08 dex, i.e. a factor of ∼1.5–12), with abundance-matching and richness methods providing the best results, irrespective of the input model assumptions. In addition, certain methods produce a significant number of catastrophic cases where the mass is under- or overestimated by a factor greater than 10. Given the steeply falling high-mass end of the cluster mass function, we recommend that richness- or abundance-matching-based methods are used in conjunction with these methods as a sanity check for studies selecting high-mass clusters. We see a stronger correlation of the recovered to input number of galaxies for both catalogues in comparison with the group/cluster mass, however, this does not guarantee that the correct member galaxies are being selected. We do not observe significantly higher scatter for either mock galaxy catalogues. Our results have implications for cosmological analyses that utilize the masses, richnesses, or abundances of clusters, which have different uncertainties when different methods are used.

Item Type: Article
Additional Information: This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2015 The authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
Keywords: Methods: numerical, Methods: statistical, Galaxies: haloes, Galaxies: kinematics and dynamics, Cosmology: observations
Schools/Departments: University of Nottingham, UK > Faculty of Science > School of Physics and Astronomy
Identification Number: 10.1093/mnras/stv421
Depositing User: Eprints, Support
Date Deposited: 08 May 2017 09:44
Last Modified: 09 May 2017 17:48
URI: http://eprints.nottingham.ac.uk/id/eprint/42576

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