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Extensions to the halo occupation distribution model for more accurate clustering predictions

Jiménez, Esteban; Contreras, Sergio; Padilla, Nelson; Zehavi, Idit; Baugh, Carlton M; Gonzalez-Perez, Violeta

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Esteban Jiménez

Sergio Contreras

Nelson Padilla

Idit Zehavi

Violeta Gonzalez-Perez


We test different implementations of the halo occupation distribution (HOD) model to reconstruct the spatial distribution of galaxies as predicted by a version of the L-GALAXIES semi-analytical model (SAM). We compare the measured two-point correlation functions of the HOD mock catalogues and the SAM samples to quantify the fidelity of the reconstruction. We use fixed number density galaxy samples selected according to stellar mass or star formation rate (SFR). We develop three different schemes to populate haloes with galaxies with increasing complexity, considering the scatter of the satellite HOD as an additional parameter in the modelling. We modify the SAM output, removing assembly bias and using a standard Navarro–Frenk–White density profile for the satellite galaxies as the target to reproduce with our HOD mocks. We find that all models give similar reproductions of the two-halo contribution to the clustering signal, but there are differences in the one-halo term. In particular, the HOD mock reproductions work equally well using either the HOD of central and satellites separately or using a model that also accounts for whether or not the haloes contain a central galaxy. We find that the HOD scatter does not have an important impact on the clustering predictions for stellar mass-selected samples. For SFR selections, we obtain the most accurate results assuming a negative binomial distribution for the number of satellites in a halo. The scatter in the satellites HOD is a key consideration for HOD mock catalogues that mimic ELG or SFR-selected samples in future galaxy surveys.


Jiménez, E., Contreras, S., Padilla, N., Zehavi, I., Baugh, C. M., & Gonzalez-Perez, V. (2019). Extensions to the halo occupation distribution model for more accurate clustering predictions. Monthly Notices of the Royal Astronomical Society, 490(3), 3532-3544.

Journal Article Type Article
Acceptance Date Sep 30, 2019
Online Publication Date Oct 4, 2019
Publication Date Dec 31, 2019
Deposit Date Jan 9, 2020
Publicly Available Date Jan 10, 2020
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 490
Issue 3
Pages 3532-3544


Published Journal Article (1.5 Mb)

Copyright Statement
This article has been accepted for publication in the Monthly notices of the Royal Astronomical Society ©: 2019 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

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