
gaussbeam
This IDL facility provides the window function in l space for a
gaussian axisymmetric beam of given FWHM.
Location in HEALPix directory tree:
src/idl/misc/gaussbeam.pro
FORMAT IDL>
beam=GAUSSBEAM (Fwhm, Lmax [, Dim])
QUALIFIERS

Fwhm
 Full Width Half Maximum of the gaussian beam, in arcmin (scalar real)

Lmax
 the window function is computed for the multipoles l in {0,...,Lmax}

Dim
 scalar integer, optional.
If absent or set to 0 or 1,
the output has size (Lmax+1) and is the temperature beam;
if set to Dim ,
the output has size (Lmax+1,Dim)
and contains in that order :
the TEMPERATURE beam,
the GRAD/ELECTRIC polarization beam
the CURL/MAGNETIC polarization beam
the TEMPERATURE*GRAD beam
DESCRIPTION
gaussbeam computes the l space window function of a gaussian beam of FWHM
Fwhm. For a sky of underlying power spectrum C(l) observed with beam of
given FWHM, the measured power spectrum will be
where B(l) is given by gaussbeam(Fwhm,Lmax). The
polarization beam is also provided (when Dim > 1) assuming a perfectly
copolarized beam (eg, Challinor et al 2000, astroph/0008228)
RELATED ROUTINESThis section lists the routines related to gaussbeam

idl
 version 6.1 or more is necessary to run gaussbeam

healpixwindow
 computes the tex2html_wrap_inline$l$ space window function associated with
a HEALPix pixel size

synfast
 f90 code to generate CMB maps of given power spectrum convolved with a gaussian beam

smoothing
 f90 code to smooth existing HEALPix maps with a gaussian beam

anafast
 f90 code to compute the power spectrum of a HEALPix sky map
EXAMPLE:
Eric Hivon
20100618

