Characterizing hydrostatic mass bias with Mock-X

Fuente: arXiv
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Main Authors: Barnes, David J., Vogelsberger, Mark, Pearce, Francesca A., Pop, Ana-Roxana, Kannan, Rahul, Cao, Kaili, Kay, Scott T., Hernquist, Lars
Format: Preprint
Published: 2020
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author Barnes, David J.
Vogelsberger, Mark
Pearce, Francesca A.
Pop, Ana-Roxana
Kannan, Rahul
Cao, Kaili
Kay, Scott T.
Hernquist, Lars
author_facet Barnes, David J.
Vogelsberger, Mark
Pearce, Francesca A.
Pop, Ana-Roxana
Kannan, Rahul
Cao, Kaili
Kay, Scott T.
Hernquist, Lars
contents Surveys in the next decade will deliver large samples of galaxy clusters that transform our understanding of their formation. Cluster astrophysics and cosmology studies will become systematics limited with samples of this magnitude. With known properties, hydrodynamical simulations of clusters provide a vital resource for investigating potential systematics. However, this is only realized if we compare simulations to observations in the correct way. Here we introduce the \textsc{Mock-X} analysis framework, a multiwavelength tool that generates synthetic images from cosmological simulations and derives halo properties via observational methods. We detail our methods for generating optical, Compton-$y$ and X-ray images. Outlining our synthetic X-ray image analysis method, we demonstrate the capabilities of the framework by exploring hydrostatic mass bias for the IllustrisTNG, BAHAMAS and MACSIS simulations. Using simulation derived profiles we find an approximately constant bias $b\approx0.13$ with cluster mass, independent of hydrodynamical method or subgrid physics. However, the hydrostatic bias derived from synthetic observations is mass-dependent, increasing to $b=0.3$ for the most massive clusters. This result is driven by a single temperature fit to a spectrum produced by gas with a wide temperature distribution in quasi-pressure equilibrium. The spectroscopic temperature and mass estimate are biased low by cooler gas dominating the emission, due to its quadratic density dependence. The bias and the scatter in estimated mass remain independent of the numerical method and subgrid physics. Our results are consistent with current observations and future surveys will contain sufficient samples of massive clusters to confirm the mass dependence of the hydrostatic bias.
format Preprint
id arxiv_https___arxiv_org_abs_2001_11508
institution arXiv
publishDate 2020
record_format arxiv
spellingShingle Characterizing hydrostatic mass bias with Mock-X
Barnes, David J.
Vogelsberger, Mark
Pearce, Francesca A.
Pop, Ana-Roxana
Kannan, Rahul
Cao, Kaili
Kay, Scott T.
Hernquist, Lars
Cosmology and Nongalactic Astrophysics
Surveys in the next decade will deliver large samples of galaxy clusters that transform our understanding of their formation. Cluster astrophysics and cosmology studies will become systematics limited with samples of this magnitude. With known properties, hydrodynamical simulations of clusters provide a vital resource for investigating potential systematics. However, this is only realized if we compare simulations to observations in the correct way. Here we introduce the \textsc{Mock-X} analysis framework, a multiwavelength tool that generates synthetic images from cosmological simulations and derives halo properties via observational methods. We detail our methods for generating optical, Compton-$y$ and X-ray images. Outlining our synthetic X-ray image analysis method, we demonstrate the capabilities of the framework by exploring hydrostatic mass bias for the IllustrisTNG, BAHAMAS and MACSIS simulations. Using simulation derived profiles we find an approximately constant bias $b\approx0.13$ with cluster mass, independent of hydrodynamical method or subgrid physics. However, the hydrostatic bias derived from synthetic observations is mass-dependent, increasing to $b=0.3$ for the most massive clusters. This result is driven by a single temperature fit to a spectrum produced by gas with a wide temperature distribution in quasi-pressure equilibrium. The spectroscopic temperature and mass estimate are biased low by cooler gas dominating the emission, due to its quadratic density dependence. The bias and the scatter in estimated mass remain independent of the numerical method and subgrid physics. Our results are consistent with current observations and future surveys will contain sufficient samples of massive clusters to confirm the mass dependence of the hydrostatic bias.
title Characterizing hydrostatic mass bias with Mock-X
topic Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2001.11508