Saskatoon 1993

Wollack et al. use Ka band (centered on 30 GHz) data from the ground-based Saskatoon 1993 experiment at Saskatoon to constrain CMBR anisotropy.

The FWHM of the beam, assumed to be gaussian, is $\sigma_{\rm FWHM} = 0.65^\circ \sqrt{8 {\rm ln} 2}$. The zero-lag window function of the stepped-scan, second harmonic lockin, three-beam experiment is

$$W_\ell = 1.839 e^{-\sigma_{\rm G}{}^2 (\ell + 0.5)^2} \s... ... J_2 \left( (\ell - 2k) \Phi_0 \right) \right]^2 , \eqno(1)$$

where $\sigma_{\rm G} = \sigma_{\rm FWHM}/\sqrt{8 {\rm ln} 2}$, $J_2$ is a Bessel function of the first kind, and $\Phi_0 = 2.45^\circ$ is half of the peak-to-peak chop angle. The normalization, $1.839$, is fixed so that a 1 $\mu$K change in a blackbody filling only the positive lobe of the sky pattern gives a detected signal of 1 $\mu$K.

The first column in the window function file is $\ell$, which runs from 2 to 350. The second column is the zero-lag $W_\ell$.

Table: Saskatoon 1993 zero-lag Window Function Parameters

$\ell_{e^{-0.5}}$	$\ell_{\rm e}$	$\ell_{\rm m}$	$\ell_{e^{-0.5}}$	$\sqrt{I(W_\ell)}$
47	67.0	69	95	1.07

The quoted bandtemperature values are computed for a flat bandpower spectrum. They are from Netterfield et al., corrected according to the caption of Figure 3 of Torbet et al. (to account for re-calibration and foreground contamination), with 11% added in quadrature to their statistical 1 $\sigma$ error bars to account for the 1 $\sigma$ calibration uncertainty.

Fig.: Saskatoon 1993 zero-lag window functions. (Postscript version here.)

REFERENCES

Link to the experiment webpage.

C.B. Netterfield, M.J. Devlin, N. Jarosik, L. Page, and E.J. Wollack, ``A Measurement of the Angular Power Spectrum of the Anisotropy in the Cosmic Microwave Background", Astrophys. J. 474, 47 (1997).

E. Torbet, et al., ``A Measurement of the Angular Power Spectrum of the Microwave Background Made from the High Chilean Andes", astro-ph/9905100 v3.

E.J. Wollack, N.C. Jarosik, C.B. Netterfield, L.A. Page, and D. Wilkinson, ``A Measurement of the Anisotropy in the Cosmic Microwave Background Radiation at Degree Angular Scales", Astrophys. J. Lett. 419, L49 (1993).