The effect of selection -- a tale of cluster mass measurement bias induced by correlation and projection

Zhang, Yuanyuan; Annis, James

doi:10.48550/arxiv.2201.02167

Cited by 2 publications

(3 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Clusters are not selected by their host halo mass, they are rather selected by their stellar or gas observables. As first pointed out by Nord et al (2008) and later shown by others (e.g., Farahi et al 2018b;Zhang & Annis 2022), a non-zero covariance between observables can induce a non-trivial biases in mass-observable relation if not accounted for properly. As we will show, this bias is not a constant factor, rather it is a function of mass and radial distance.…”

Section: Cluster Mass Calibrationmentioning

confidence: 89%

“…Consequently, the covariance between the baryon and dark matter density profiles not only provides new insights on the interactions between dark matter, gas, and stars at different scales, but is also an important model ingredient when performing multi-wavelength cluster mass calibration or a cross-correlation analysis. For instance, when clusters are selected on their observables, other than halo mass, this covariance matrix can induce additive bias in the expected properties of halos, such as the weak-lensing signal (Zhang & Annis 2022). In this paper, we quantify the impact of this covariance on the expected cumulative mass profile for a optically-selected cluster sample.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Correlations of Dark Matter, Gas and Stellar Profiles in Dark Matter Halos

Farahi,

Nagai,

Anbajagane

2022

Preprint

View full text Add to dashboard Cite

Halos of similar mass and redshift exhibit a large degree of variability in their differential properties, such as dark matter, hot gas, and stellar mass density profiles. This variability is an indicator of diversity in the formation history of these dark matter halos that is reflected in the coupling of scatters about the mean relations. In this work, we show that the strength of this coupling depends on the scale at which halo profiles are measured. By analyzing the outputs of the IllustrisTNG hydrodynamical cosmological simulations we report the radial-and mass-dependent couplings between the dark matter, hot gas, and stellar mass radial density profiles utilizing the population diversity in dark matter halos. We find that for same mass halos the scatters in density of baryons and dark matter are strongly coupled at large scales (r > R 200 ); but the coupling between gas and dark matter density profiles fades near the core of halos (r < 0.3R 200 ). We then show that the correlation between halo profile and integrated quantities induces a radius-dependent additive bias in the profile observables of halos when halos are selected on properties other than their mass. We discuss the impact of this effect on cluster abundance and cross-correlations cosmology with multi-wavelength cosmological surveys.

show abstract

Section: Cluster Mass Calibrationmentioning

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Correlations of Dark Matter, Gas and Stellar Profiles in Dark Matter Halos

Farahi,

Nagai,

Anbajagane

2022

Preprint

View full text Add to dashboard Cite

show abstract

“…Sartoris et al 2016). Projection effects can introduce large selection biases in cosmological cluster studies based on weak-lensing mass estimates (Sunayama et al 2020;Abbott et al 2020;Zhang & Annis 2022). Optical observations have a wealth of information, which is currently not fully utilized by weak-lensing studies, instead relying on assumptions of sphericity for large enough samples of clusters.…”

Section: Discussionmentioning

confidence: 99%

Brightest cluster galaxies trace weak lensing mass bias and halo triaxiality in the three hundred project

Herbonnet

Crawford

Avestruz

et al. 2022

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

Galaxy clusters have a triaxial matter distribution. The weak-lensing signal, an important part in cosmological studies, measures the projected mass of all matter along the line-of-sight, and therefore changes with the orientation of the cluster. Studies suggest that the shape of the brightest cluster galaxy (BCG) in the centre of the cluster traces the underlying halo shape, enabling a method to account for projection effects. We use 324 simulated clusters at four redshifts between 0.1 and 0.6 from ‘The Three Hundred Project’ to quantify correlations between the orientation and shape of the BCG and the halo. We find that haloes and their embedded BCGs are aligned, with an average ∼20 degree angle between their major axes. The bias in weak lensing cluster mass estimates correlates with the orientation of both the halo and the BCG. Mimicking observations, we compute the projected shape of the BCG, as a measure of the BCG orientation, and find that it is most strongly correlated to the weak-lensing mass for relaxed clusters. We also test a 2-dimensional cluster relaxation proxy measured from BCG mass isocontours. The concentration of stellar mass in the projected BCG core compared to the total stellar mass provides an alternative proxy for the BCG orientation. We find that the concentration does not correlate to the weak-lensing mass bias, but does correlate with the true halo mass. These results indicate that the BCG shape and orientation for large samples of relaxed clusters can provide information to improve weak-lensing mass estimates.

show abstract

The effect of selection -- a tale of cluster mass measurement bias induced by correlation and projection

Cited by 2 publications

References 30 publications

Correlations of Dark Matter, Gas and Stellar Profiles in Dark Matter Halos

Correlations of Dark Matter, Gas and Stellar Profiles in Dark Matter Halos

Brightest cluster galaxies trace weak lensing mass bias and halo triaxiality in the three hundred project

Contact Info

Product

Resources

About