S-Z anisotropy and cluster counts: Consistent selection of σ8 and the temperature-mass relation

Sharon Sadeh*, Yoel Rephaeli

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


The strong dependence of the mass variance parameter, σ8, on the adopted cluster mass-temperature relation is explored. A recently compiled X-ray cluster catalog and various mass-temperature relations are used to derive the corresponding values of σ8. Calculations of the power spectrum of the CMB anisotropy induced by the Sunyaev-Zeldovich effect and cluster number counts are carried out in order to assess the need for a consistent choice of the mass-temperature scaling and the parameter σ8. We find that the consequences of inconsistent choice of the mass-temperature relation and σ8 could be quite substantial, including a considerable mis-estimation of the magnitude of the power spectrum and cluster number counts. Our results can partly explain the large scatter between published estimates of the power spectrum and number counts. We also show that the range of values of the power-law index in the scaling C ∼σ86-7 deduced in previous studies is likely overestimated; we obtain a more moderate dependence, C ∼σ84.

Original languageEnglish
Pages (from-to)373-382
Number of pages10
JournalNew Astronomy
Issue number5
StatePublished - Jun 2004


FundersFunder number
Israeli Science Foundation729⧹00-03
Tel-Aviv University


    • Cosmic microwave background
    • Cosmology: miscellaneous
    • Galaxies: clusters: general


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