Мақола

First‐Year <i>Wilkinson Microwave Anisotropy Probe</i> ( <i>WMAP</i> ) Observations: Tests of Gaussianity

Eiichiro KomatsuDepartment of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544A. KogutNASA Goddard Space Flight Center, Code 685, Greenbelt, MD 20771M. R. NoltaDepartment of Physics, Jadwin Hall, Princeton, NJ 08544C. L. BennettNASA Goddard Space Flight Center, Code 685, Greenbelt, MD 20771M. HalpernDepartment of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1, CanadaG. HinshawNASA Goddard Space Flight Center, Code 685, Greenbelt, MD 20771N. JarosikDepartment of Physics, Jadwin Hall, Princeton, NJ 08544M. LimonNASA Goddard Space Flight Center, Code 685, Greenbelt, MD 20771S. S. MeyerDepartments of Astrophysics and Physics, EFI, and CfCP, University of Chicago, Chicago, IL 60637Lyman A. PageDepartment of Physics, Jadwin Hall, Princeton, NJ 08544David N. SpergelDepartment of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544Gregory S. TuckerDepartment of Physics, Brown University, Providence, RI 02912Licia VerdeChandra FellowEdward J. WollackNASA Goddard Space Flight Center, Code 685, Greenbelt, MD 20771E. L. Wright

2003en

ABI

Аннотация

We present limits to the amplitude of non-Gaussian primordial fluctuations in the WMAP 1-year cosmic microwave background sky maps. A non-linear coupling parameter, f_NL, characterizes the amplitude of a quadratic term in the primordial potential. We use two statistics: one is a cubic statistic which measures phase correlations of temperature fluctuations after combining all configurations of the angular bispectrum. The other uses the Minkowski functionals to measure the morphology of the sky maps. Both methods find the WMAP data consistent with Gaussian primordial fluctuations and establish limits, -58<f_NL<134, at 95% confidence. There is no significant frequency or scale dependence of f_NL. The WMAP limit is 30 times better than COBE, and validates that the power spectrum can fully characterize statistical properties of CMB anisotropy in the WMAP data to high degree of accuracy. Our results also validate the use of a Gaussian theory for predicting the abundance of clusters in the local universe. We detect a point-source contribution to the bispectrum at 41 GHz, b_src = (9.5+-4.4) X 1e-5 uK^3 sr^2, which gives a power spectrum from point sources of c_src = (15+-6) X 1e-3 uK^2 sr in thermodynamic temperature units. This value agrees well with independent estimates of source number counts and the power spectrum at 41 GHz, indicating that b_src directly measures residual source contributions.

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DOI: 10.1086/377220

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