科研之友
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摘要
The interaction of the cosmic microwave background (CMB) with the hot gas in clusters of galaxies, the so-called Sunyaev-Zel'dovich (SZ) effect, is a very useful tool that allows us to determine the physical conditions in such clusters and fundamental parameters of the cosmological models. In this work, we determine the dependence of the SZ surface brightness amplitude with redshift and mass of the clusters. We have used PLANCK+IRAS data in the microwave-far-infrared and a catalog with. >= 10(5) clusters of galaxies extracted from the SDSS by Wen et al. We estimate and subtract the dust emission from those clusters. From the residual flux, we extract its SZ flux densities. The absolute value of the SZ amplitude indicates that the gas mass is around 10% of the total mass for cluster masses of M similar to 10(14) M circle dot This amplitude is compatible with no evolution with redshift and proportional to M2.70+0.37 (using X-ray derived masses) or M2.51+0.38 (using weak-lensing derived masses), with some tension regarding the expectations of the self-similar dependence (amplitude proportional to M-5/3). Other secondary products of our analysis include that clusters have a dust emission with emissivity index beta similar to 2 and temperature T similar to 25 K; we confirm that the CMB temperature agrees with a dependence ofT(0)(1 + z) with clusters of much lower mass than those. explored previously; and we find that the cluster masses derived by Wen et al. from a richness-mass than those. explored previously; and we find that the cluster masses derived by Wen et al. from a richness-mass relationship are biased by a factor of (1 + z)(-1.8) with respect to the X-ray and weak-lensing measurements.
- 出版日期2017-5-10
