Cluster Cosmology with the Velocity Distribution Function of the HeCS-SZ Sample

Ntampaka, Michelle; Rines, K.; Trac, Hy

doi:10.3847/1538-4357/ab2a00

Cited by 9 publications

(5 citation statements)

References 55 publications

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“…Also, constraints on structure growth parameter combination S 8 from cluster abundance data have been obtained by Refs. [905][906][907][908][909][910].…”

Section: The Observational Evidence For Weaker Growth Indicated By Th...mentioning

confidence: 99%

Challenges for $Λ$CDM: An update

Perivolaropoulos,

Skara

2021

Preprint

224

298

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A number of challenges of the standard ΛCDM model has been emerging during the past few years as the accuracy of cosmological observations improves. In this review we discuss in a unified manner many existing signals in cosmological and astrophysical data that appear to be in some tension (2σ or larger) with the standard ΛCDM model as defined by the Planck18 parameter values. In addition to the major well studied 5σ challenge of ΛCDM (the Hubble H0 crisis) and other well known tensions (the growth tension and the lensing amplitude AL anomaly), we discuss a wide range of other less discussed less-standard signals which appear at a lower statistical significance level than the H0 tension (also known as 'curiosities' in the data) which may also constitute hints towards new physics. For example such signals include cosmic dipoles (the fine structure constant α, velocity and quasar dipoles), CMB asymmetries, BAO Lyα tension, age of the Universe issues, the Lithium problem, small scale curiosities like the core-cusp and missing satellite problems, quasars Hubble diagram, oscillating short range gravity signals etc. The goal of this pedagogical review is to collectively present the current status of these signals and their level of significance, with emphasis to the Hubble crisis and refer to recent resources where more details can be found for each signal. We also briefly discuss possible theoretical approaches that can potentially explain the non-standard nature of some of these signals.

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“…Also, constraints on structure growth parameter combination S 8 from cluster abundance data have been obtained by Refs. [905][906][907][908][909][910].…”

Section: The Observational Evidence For Weaker Growth Indicated By Th...mentioning

confidence: 99%

Challenges for $Λ$CDM: An update

Perivolaropoulos,

Skara

2021

Preprint

224

298

View full text Add to dashboard Cite

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“…F or e xample, Bocquet et al ( 2015 , see Sections 3 and 5.1) discuss that a 1 per cent prior on the velocity bias impro v es constraints on both astrophysical and cosmological parameters connected to galaxy clusters by ≈30 per cent . Cluster counts as a function of their galaxy velocity dispersion and redshift has also emerged as an alternative approach for cluster cosmology (Caldwell et al 2016 ;Ntampaka et al 2017 ;Ntampaka, Rines & Trac 2019 ;Kirkpatrick et al 2021 ), and the velocity bias is a critical component in forward modelling the rele v ant observ able from cosmological parameters.…”

Section: R E V I S E D M a S S S C A L E O F L Owz S D S S C L U S T ...mentioning

confidence: 99%

Galaxy velocity bias in cosmological simulations: towards per cent-level calibration

Anbajagane

Aung

Evrard

et al. 2021

Monthly Notices of the Royal Astronomical Society

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Galaxy cluster masses, rich with cosmological information, can be estimated from internal dark matter (DM) velocity dispersions, which in turn can be observationally inferred from satellite galaxy velocities. However, galaxies are biased tracers of the DM, and the bias can vary over host halo and galaxy properties as well as time. We precisely calibrate the velocity bias, bv — defined as the ratio of galaxy and DM velocity dispersions — as a function of redshift, host halo mass, and galaxy stellar mass threshold (M⋆, sat), for massive haloes (M200c > 1013.5 M⊙) from five cosmological simulations: IllustrisTNG, Magneticum, Bahamas + Macsis, The Three Hundred Project, and MultiDark Planck-2. We first compare scaling relations for galaxy and DM velocity dispersion across simulations; the former is estimated using a new ensemble velocity likelihood method that is unbiased for low galaxy counts per halo, while the latter uses a local linear regression. The simulations show consistent trends of bv increasing with M200c and decreasing with redshift and M⋆, sat. The ensemble-estimated theoretical uncertainty in bv is 2-3%, but becomes percent-level when considering only the three highest resolution simulations. We update the mass–richness normalization for an SDSS redMaPPer cluster sample, and find our improved bv estimates reduce the normalization uncertainty from 22% to 8%, demonstrating that dynamical mass estimation is competitive with weak lensing mass estimation. We discuss necessary steps for further improving this precision. Our estimates for bv(M200c, M⋆, sat, z) are made publicly available.

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“…For example, Bocquet et al (2015, see Section 3 and Section 5.1) discuss that a 1% prior on the velocity bias improves constraints on both astrophysical and cosmological parameters connected to galaxy clusters by ≈ 30%. Cluster counts as a function of their galaxy velocity dispersion and redshift has also emerged as an alternative approach for cluster cosmology (Caldwell et al 2016;Ntampaka et al 2017Ntampaka et al , 2019Kirkpatrick et al 2021), and the velocity bias is a critical component in forward modelling the relevant observable from cosmological parameters. 4), and the fractional uncertainty on each estimate (right panel).…”

Section: Revised Mass Scale Of Low-𝑍 Sdss Clustersmentioning

confidence: 99%

Galaxy Velocity Bias in Cosmological Simulations: Towards Percent-level Calibration

Anbajagane,

Aung,

Evrard

et al. 2021

Preprint

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Galaxy cluster masses, rich with cosmological information, can be estimated from internal dark matter (DM) velocity dispersions, which in turn can be observationally inferred from satellite galaxy velocities. However, galaxies are biased tracers of the DM, and the bias can vary over host halo and galaxy properties as well as time. We precisely calibrate the velocity bias, 𝑏 𝑣 -defined as the ratio of galaxy and DM velocity dispersions -as a function of redshift, host halo mass, and galaxy stellar mass threshold (𝑀 ★, sat ), for massive halos (𝑀 200c > 10 13.5 M ) from five cosmological simulations: IllustrisTNG, Magneticum, Bahamas + Macsis, The Three Hundred Project, and MultiDark Planck-2. We first compare scaling relations for galaxy and DM velocity dispersion across simulations; the former is estimated using a new ensemble velocity likelihood method that is unbiased for low galaxy counts per halo, while the latter uses a local linear regression. The simulations show consistent trends of 𝑏 𝑣 increasing with 𝑀 200c and decreasing with redshift and 𝑀 ★, sat . The ensemble-estimated theoretical uncertainty in 𝑏 𝑣 is 2-3%, but becomes percent-level when considering only the three highest resolution simulations. We update the mass-richness normalization previously estimated by Farahi et al. (2016) for an SDSS redMaPPer cluster sample. The improved accuracy of our 𝑏 𝑣 estimates reduces the mass normalization uncertainty from 22% to 8%, demonstrating that dynamical estimation techniques can be competitive with weak lensing in calibrating population mean masses. We discuss necessary steps for further improving this precision. Our estimates for 𝑏 𝑣 (𝑀 200c , 𝑀 ★, sat , 𝑧) are made publicly available.

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Cluster Cosmology with the Velocity Distribution Function of the HeCS-SZ Sample

Cited by 9 publications

References 55 publications

Challenges for $Λ$CDM: An update

Challenges for $Λ$CDM: An update

Galaxy velocity bias in cosmological simulations: towards per cent-level calibration

Galaxy Velocity Bias in Cosmological Simulations: Towards Percent-level Calibration

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