Ready for delensing use lensing maps 02.00

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J. Carron Sept 30 2018.

This page describe the 300 lensing tracers maps (healpy alm fits files, with lmax=3000) available at

    /project/projectdirs/cmbs4/reanalysis/phi_recons/02.00_carron_180920/plms_sepTP_apo_lmin200lmax3000_fsky5pc_cut10_180925/ready_for_delensing_use

These maps were directly built from the quadratic estimated raw lensing maps Lensing reconstructions 02.00, after Wiener-filtering and mean-field (contamination of the lensing estimate by mask and noise anisotropies) subtraction, as described below. They can be used as is for delensing.

There are 3 types of maps:

  • sim_ptt_????_lmax3000.fits

built from temperature data only, with ???? from 0000 to 0099

  • sim_p_p_????_lmax3000.fits

built from polarization data only,

  • sim_p_????_lmax3000.fits

built from combination and temperature and polarization data.

Wiener-filter

The Wiener-filter C / C + N0 is isotropic, and is given by the last column of the files

   clwf_{ptt, p_p, p}.dat

in the same folder. The noise spectra are obtained empirically, by taking (twice) the spectrum of a lensing reconstruction where the two legs of the quadratic estimator are independent, and averaging over 100 such reconstructions.

Mean-fields

To subtract the mean-field from one lensing estimate, we have subtracted the average of the lensing reconstructions, excluding that very estimate (resulting in the average of 99 lensing maps). This adds a small, ~1% contribution to the reconstruction noise which is neglected in the Wiener-filter. This procedure also causes the simulations to be not exactly independent anymore, even if this is a small effect.