The Radial Acceleration Relation in CLASH Galaxy Clusters

Tian, Yong; Umetsu, Keiichi; Ko, C. M.; Donahue, M.; Chiu, I-Non

doi:10.3847/1538-4357/ab8e3d

“…22 represents the mean density interior to R min ¼ 40h À1 kpc corresponding to the typical resolution limit of their HST stronglensing analysis, d# % 10 arcsec. This scale R min is about twice the typical half-light radius of the CLASH BCGs (see Tian et al 2020), within which the stellar baryons dominate the total mass of the clusters (e.g., Caminha et al 2019). Determinations of the central slope of the dark-matter density profile q DM ðrÞ in clusters require additional constraints on the total mass in the innermost region, such as from stellar kinematics of the BCG (Newman et al 2013a).…”

Section: Cluster Mass Distributionmentioning

confidence: 99%

Cluster–galaxy weak lensing

Umetsu

¹

2020

Astron Astrophys Rev

Self Cite

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Weak gravitational lensing of background galaxies provides a direct probe of the projected matter distribution in and around galaxy clusters. Here, we present a self-contained pedagogical review of cluster–galaxy weak lensing, covering a range of topics relevant to its cosmological and astrophysical applications. We begin by reviewing the theoretical foundations of gravitational lensing from first principles, with a special attention to the basics and advanced techniques of weak gravitational lensing. We summarize and discuss key findings from recent cluster–galaxy weak-lensing studies on both observational and theoretical grounds, with a focus on cluster mass profiles, the concentration–mass relation, the splashback radius, and implications from extensive mass-calibration efforts for cluster cosmology.

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“…To this end, we use gravitational lensing: the perturbation of light inside a gravitational potential as described by relativistic theories such as GR. Both weak and strong gravitational lensing were used by Tian et al (2020) to measure the RAR from observations of 20 galaxy clusters targeted by the CLASH survey. However, due to the high cluster masses, the accelerations probed by these measurements were of the same order as those measurable with galaxy rotation curves.…”

Section: Introductionmentioning

confidence: 99%

The weak lensing radial acceleration relation: Constraining modified gravity and cold dark matter theories with KiDS-1000

Brouwer

¹

,

Oman²,

Valentijn³

et al. 2021

A&A

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We present measurements of the radial gravitational acceleration around isolated galaxies, comparing the expected gravitational acceleration given the baryonic matter (gbar) with the observed gravitational acceleration (gobs), using weak lensing measurements from the fourth data release of the Kilo-Degree Survey (KiDS-1000). These measurements extend the radial acceleration relation (RAR), traditionally measured using galaxy rotation curves, by 2 decades in gobs into the low-acceleration regime beyond the outskirts of the observable galaxy. We compare our RAR measurements to the predictions of two modified gravity (MG) theories: modified Newtonian dynamics and Verlinde’s emergent gravity (EG). We find that the measured relation between gobs and gbar agrees well with the MG predictions. In addition, we find a difference of at least 6σ between the RARs of early- and late-type galaxies (split by Sérsic index and u − r colour) with the same stellar mass. Current MG theories involve a gravity modification that is independent of other galaxy properties, which would be unable to explain this behaviour, although the EG theory is still limited to spherically symmetric static mass models. The difference might be explained if only the early-type galaxies have significant (Mgas ≈ M⋆) circumgalactic gaseous haloes. The observed behaviour is also expected in Λ-cold dark matter (ΛCDM) models where the galaxy-to-halo mass relation depends on the galaxy formation history. We find that MICE, a ΛCDM simulation with hybrid halo occupation distribution modelling and abundance matching, reproduces the observed RAR but significantly differs from BAHAMAS, a hydrodynamical cosmological galaxy formation simulation. Our results are sensitive to the amount of circumgalactic gas; current observational constraints indicate that the resulting corrections are likely moderate. Measurements of the lensing RAR with future cosmological surveys (such as Euclid) will be able to further distinguish between MG and ΛCDM models if systematic uncertainties in the baryonic mass distribution around galaxies are reduced.

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“…For both the datasets, we adopt uniform priors on γ 0 and γ 1 : −1.5 γ 0 1.5 and −2.0 γ 1 3.0. For the intrinsic scatter, similar to [78], we assume log-uniform priors between 10 −5 and 0.1. The log-uniform prior ensures that the intrinsic scatter is greater than zero.…”

Section: Analysis and Resultsmentioning

confidence: 99%

A model-independent test of the evolution of gas depletion factor for SPT-SZ and Planck ESZ clusters

Bora

¹

,

Desai

²

2021

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The gas mass fraction in galaxy clusters has been widely used to determine cosmological parameters. This method assumes that the ratio of the cluster gas mass fraction to the cosmic baryon fraction ($$\gamma (z)$$ γ ( z ) ) is constant as a function of redshift. In this work, we look for a time evolution of $$\gamma (z)$$ γ ( z ) at $$R_{500}$$ R 500 by using both the SPT-SZ and Planck Early SZ (ESZ) cluster data, in a model-independent fashion without any explicit dependence on the underlying cosmology. For this calculation, we use a non-parametric functional form for the Hubble parameter obtained from Gaussian Process regression using cosmic chronometers. We parameterize $$\gamma (z)$$ γ ( z ) as: $$\gamma (z)= \gamma _0(1+\gamma _1 z)$$ γ ( z ) = γ 0 ( 1 + γ 1 z ) to constrain the redshift evolution. We find contradictory results between both the samples. For SPT-SZ, $$\gamma (z)$$ γ ( z ) decreases as a function of redshift (at more than 5$$\sigma $$ σ ), whereas a positive trend with redshift is found for Planck ESZ data (at more than 4$$\sigma $$ σ ). We however find that the $$\gamma _1$$ γ 1 values for a subset of SPT-SZ and Planck ESZ clusters between the same redshift interval agree to within $$1\sigma $$ 1 σ . When we allow for a dependence on the halo mass in the evolution of the gas depletion factor, the $$4-5\sigma $$ 4 - 5 σ discrepancy reduces to $$2\sigma $$ 2 σ .

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The Radial Acceleration Relation in CLASH Galaxy Clusters

Cited by 61 publications

References 80 publications

Cluster–galaxy weak lensing

Cluster–galaxy weak lensing

The weak lensing radial acceleration relation: Constraining modified gravity and cold dark matter theories with KiDS-1000

A model-independent test of the evolution of gas depletion factor for SPT-SZ and Planck ESZ clusters

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