First-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Beam Profiles and Window Functions

By L. Page, C. Barnès, Gary F. Hinshaw, David N. Spergel, J. Weiland, Edward J. Wollack, C. Bennett, Mark Halpern, N. Jarosik, Alan Kogut and 9 more. 2003

142 citations recorded by the source corpus.

Knowledge of the beam profiles is of critical importance for interpreting data from cosmic microwave background experiments. In this paper, we present the characterization of the in-flight optical response of the WMAP satellite. The main-beam intensities have been mapped to ≤-30 dB of their peak values by observing Jupiter with the satellite in the same observing mode as for CMB observations. The beam patterns closely follow the prelaunch expectations. The full width at half-maximum is a function of frequency and ranges from 0.°82 at 23 GHz to 0.°21 at 94 GHz; however, the beams are not Gaussian. We present (a) the beam patterns for all 10 differential radiometers, showing that the patterns are substantially independent of polarization in all but the 23 GHz channel; (b) the effective symmetrized beam patterns that result from WMAP's compound spin observing pattern; (c) the effective window functions for all radiometers and the formalism for propagating the window function uncertainty; and (d) the conversion factor from point-source flux to antenna temperature. A summary of the systematic uncertainties, which currently dominate our knowledge of the beams, is also presented. The constancy of Jupiter's temperature within a frequency band is an essential check of the optical system. The tests enable us to report a calibration of Jupiter to 1%-3% accuracy relative to the CMB dipole.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/765607917e02eb69cb5b28673fc083f20f10c033

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

Citations in the corpus

First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Foreground Emission (2003, unknown): “The maps are then filtered by bl/(b 2 lC cmb l +C noise), (Tegmark & de Oliveira-Costa 1998; Refregier et al. 2000), where bl is the transfer function of the WMAP beam pattern (Page et al. 2003a), Ccmbl is the CMB angular power spectrum, and Cnoise is the noise power.”
Three-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Implications for Cosmology (2006, unknown): “The accurately determined peak position constrains 0:275 m h (Page et al. 2003a), fixes the cosmological age, and determines the direction of the degeneracy surface.”
A full sky, low foreground, high resolution CMB map from WMAP (2008, background): “Conversion factors between flux density and Gaussian amplitude, as well as the FWHM of the Gaussian profile are taken from Table 5 of Page et al. (2003) for one year data, and corresponding updates for the more recent releases.”
A Measurement of the Angular Power Spectrum of the CMB Temperature Anisotropy from the 2003 Flight of BOOMERANG (2005, methodology): “As has become common practice (see, for example, de Bernardis et al. (2002); Ruhl et al. (2003); Page et al. (2003)), we calculate a model independent characterization of the location, amplitude, and significance of the features in the power spectrum through a comparison of the goodness of fit of a…”
Power Spectrum Estimation from High-Resolution Maps by Gibbs Sampling (2004, background): “As mentioned above, our main scientiﬁc goal of the current work is to analyze the ﬁrst-year WMAP data, and for that reason we assume the beam to be azimuthally symmetric (Page et al. 2003).”
FIVE-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE OBSERVATIONS: COSMOLOGICAL INTERPRETATION (2008, unknown): “Note that the change in the beam is fully consistent with the 1-σ error of the previous WMAP beam reported in Page et al. (2003).”