# Difference between revisions of "Beam Window Functions"

Beam window functions have computed with the Febecop Pipeline (as described there), and the QuickPol pipeline (see Hivon et al, 2017 [1], and the 2018 Planck Likelihood paper).

The beam window functions relate, over the full sky or over a masked sky, the angular power spectrum measured (in the absence of noise) on a map produced by a set of detectors , to the true underlying sky angular power spectrum (assumed to have isotropic statistical properties, as is the case for the CMB).

1. QuickPol effective beam window functions

They are available in two forms:

• The beam window functions

such that \\ \\ for X=T,E or B, and where is the pixel window function, which depends on the resolution parameter Nside (=2048 for Planck HFI maps). They are provided in FITS files, in a format compatible with [[2]] tools such as synfast and smoothing, as well as with PolSpice.

• Beam matrix

### References

1. Hivon E., Mottet, S. & Ponthieu N., 2017 QuickPol: Fast calculation of effective beam matrices for CMB polarization A&A 598, A25, [[1]]

Cosmic Microwave background

(Planck) High Frequency Instrument

Flexible Image Transfer Specification