Introducing decorated HODs: modelling assembly bias in the galaxy–halo connection
Andrew P. Hearin,Andrew R. Zentner,Frank C. van den Bosch,Duncan Campbell,Erik J. Tollerud,Erik J. Tollerud +5 more
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In this paper, the authors introduce decorated HODs, a new, exible class of models designed to account for assembly bias, which minimally expand the parameter space and maximize the independence between traditional and novel HOD parameters.Abstract:
The connection between galaxies and dark matter halos is often inferred from data using probabilistic models, such as the Halo Occupation Distribution (HOD). Conventional HOD formulations assume that only halo mass governs the galaxy-halo connection. Violations of this assumption, known as galaxy assembly bias, threaten the HOD program. We introduce decorated HODs, a new, exible class of models designed to account for assembly bias. Decorated HODs minimally expand the parameter space and maximize the independence between traditional and novel HOD parameters. We use decorated HODs to quantify the inuence of assembly bias on clustering and lensing statistics. For SDSS-like samples, the impact of assembly bias on galaxy clustering can be as large as a factor of two on r 200 kpc scales and 15% in the linear regime. Assembly bias can either enhance or diminish clustering on large scales, but generally increases clustering on scales r . 1 Mpc. We performed our calculations with Halotools, an open-source, community-driven python package for studying the galaxy-halo connection (http://halotools.readthedocs.org). We conclude by describing the use of decorated HODs to treat assembly bias in otherwise conventional likelihood analyses.read more
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First results from the IllustrisTNG simulations: matter and galaxy clustering
Volker Springel,Volker Springel,Rüdiger Pakmor,Annalisa Pillepich,Rainer Weinberger,Dylan Nelson,Lars Hernquist,Mark Vogelsberger,Shy Genel,Shy Genel,Paul Torrey,Federico Marinacci,Jill Naiman +12 more
TL;DR: In this article, the authors used the IllustrisTNG simulations to study the non-linear correlation functions and power spectra of baryons, dark matter, galaxies and haloes over an exceptionally large range of scales.
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Disruption of Dark Matter Substructure: Fact or Fiction?
TL;DR: In this article, the authors use both analytical estimates and idealized numerical simulations to investigate whether this disruption is mainly physical, due to tidal heating and stripping, or numerical (i.e. artificial).
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Dark Matter Substructure in Numerical Simulations: A Tale of Discreteness Noise, Runaway Instabilities, and Artificial Disruption
Frank C. van den Bosch,Go Ogiya +1 more
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Linking Early and Late Type Galaxies to their Dark Matter Haloes
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Nbodykit: an open-source, massively parallel toolkit for large-scale structure
Nick Hand,Yu Feng,Florian Beutler,Yin Li,Yin Li,Yin Li,Chirag Modi,Uroš Seljak,Zachary Slepian,Zachary Slepian +9 more
TL;DR: Nbodykit, an open-source, massively parallel Python toolkit for analyzing large-scale structure (LSS) data, is presented, using Python bindings of the Message Passing Interface (MPI), to provide parallel implementations of many commonly used algorithms in LSS.
References
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