OVERVIEW
========
This directory contains data products for full sky synchrotron emission polarization evaluated at a
frequency of 30 GHz.
The data is obtained by combining WMAP K, Ka and Q band
with Planck LFI 30 GHz and 44 GHz observations, assuming
a power law synchrotron emission scaling with frequency,
with spectral index -3.1.

The pipeline for obtaining the data products is
described in some detail in Delabrouille, 2024,
arXiv:2403.18123.

The data can be found in the PolarSync-2403-18123/
directory.

MAIN DATA PRODUCTS
==================
Files are as follows:
- synchrotron_alm_EB_60arcmin.fits 
contains the full-sky harmonic coefficients a_lm for the
E and B fields
- synchrotron_map_QU_60arcmin.fits 
contains the corresponding full-sky healpix maps at
nside=1024.

Both are in units of microK Rayleigh-Jeans (Antenna 
temperature). The effective beam is a 1-degree Gaussian
for ell<950, multiplied by a cosine squared taper
between ell=950 and ell=1000, and vanishes for ell>1000.

- zone-masks.fits
contains a Healpix map with four values, from 0 to 3,
corresponding to different levels of synchrotron
emission, from the lowest emission (value of 0) to the
highest emission (value of 3, in the very center of the
Galactic ridge).

- source-mask.fits
contains a Healpix map with two values, from 0 to 1. A
value of 1 is assigned to pixels potentially impacted by
a compact source of radio emission.

MONTE-CARLO NOISE SIMULATIONS
=============================
The Noise-MC/ directory contains 200 simulations of 
projected WMAP and Planck noise. The data format is the
same as for synchrotron_alm_EB_60arcmin.fits

MONTE-CARLO SCALING SIMULATIONS
===============================
The Scaling-MC/ directory contains 50 maps obtained with
the same pipeline as synchrotron_alm_EB_60arcmin.fits,
but assuming different synchrotron spectral indices.
Files are named as follows:
synchrotron_alm_EB_60arcmin-X.XXXXX.fits
where -X.XXXXX stands for the spectral index that was
assumed for generating that particular data product.


UPDATE: NOISE STANDARD DEVIATION MAP
=====================================
Added on March 15, 2025:
A Healpix map of noise standard deviation for total 
polarized intensity is made available for convenience.
This map corresponds to the noise level displayed in the
middle panel of figure 8 of the publication.
It is computed from the average variance of 200 noise
simulations:
sqrt( (sum_{i=1}^{200} (Q^2+U^2)) / 200)
The file is noise_PI_200sims_60arcmin.fits