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Effect of Halo Assembly Bias on Self Calibration in Galaxy Cluster Surveys.


DE2008928355

Publication Date 2008
Personal Author Wu, H. Y.; Rozo, E.; Wechsler, R. H.
Page Count 12
Abstract Self-calibration techniques for analyzing cluster counts rely on using the abundance and the clustering amplitude of clusters to simultaneously constrain cosmological parameters and the relation between halo mass and its observable mass tracer. It was recently discovered that the clustering amplitude of halos depends not only on halo mass, but also on various secondary variables such as halo formation time and concentration; these dependences are collectively termed 'assembly bias'. Using a modified Fisher matrix formalism, we explore whether these secondary variables have a significant impact on studying the properties of dark energy with self calibration in current (SDSS) and near future (DES, SPT, and LSST) cluster surveys. We find that for an SDSS-like survey, secondary dependences of halo bias are insignificant given the expected large statistical uncertainties in dark energy parameters. For SPT- or DES-like survey volumes, we find that the dependence of halo bias on secondary variables is not a significant systematic provided the scatter in the observable-mass relation is 20% or lower, as expected for X-ray or SZ surveys. At higher scatter (e.g. values currently possible with optical surveys), significant systematic errors are possible, depending on how strongly the cluster observable correlates with the secondary variables at fixed mass. For an LSST-like survey volume, this systematic is likely to be important even for lower scatter values or for less correlated observables.
Keywords
  • Galaxy clusters
  • Calibration
  • Abundance
  • Amplitudes
  • Cosmological parameters
  • Self-calibration techniques
  • Cluster counts
  • Halo mass
Source Agency
  • Technical Information Center Oak Ridge Tennessee
Corporate Authors Stanford Linear Accelerator Center, CA.; Department of Energy, Washington, DC.
Supplemental Notes Sponsored by Department of Energy, Washington, DC.
Document Type Technical Report
NTIS Issue Number 200824
Contract Number
  • DE-AC02-76SF00515
Effect of Halo Assembly Bias on Self Calibration in Galaxy Cluster Surveys.
Effect of Halo Assembly Bias on Self Calibration in Galaxy Cluster Surveys.
DE2008928355

  • Galaxy clusters
  • Calibration
  • Abundance
  • Amplitudes
  • Cosmological parameters
  • Self-calibration techniques
  • Cluster counts
  • Halo mass
  • Technical Information Center Oak Ridge Tennessee
  • DE-AC02-76SF00515
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