# Specially processed maps

## Overview

A general description of the product, including e.g. figures related to the contents (e.g. maps, tables), and some explanation of its scientific meaning. If there are scientific warnings about the use of the product (User’s caveats), they should also be given here, or at least references to other explanatory documents (papers etc).

## Lensing map

### Description

The fiducial Planck lensing potential map is made from a minimum variance combination of the 143 and 217 GHz Planck maps on approximately 70% of the sky, using 857GHz as a dust template. This is the same lens reconstruction on which the Planck lensing likelihood is based.

We distribute:

PHIBAR
A (transfer-function convolved) map of the lensing potential, in NSIDE 2048 HEALPix([http://healpix.sourceforge.net Hierarchical Equal Area isoLatitude Pixelation of a sphere], <ref name="[[:Template:Gorski2005]]">[http://iopscience.iop.org/0004-637X/622/2/759/pdf/0004-637X_622_2_759.pdf '''HEALPix: A Framework for High-Resolution Discretization and Fast Analysis of Data Distributed on the Sphere'''], K. M. G&oacute;rski, E. Hivon, A. J. Banday, B. D. Wandelt, F. K. Hansen, M. Reinecke, M. Bartelmann, ApJ, '''622''', 759-771, (2005). RING format. It is obtained by convolving the lensing potential estimate \hat{\phi} with the lensing response function $R_L^{\phi\phi}$.
This is a NSIDE 2048 HEALPix([http://healpix.sourceforge.net Hierarchical Equal Area isoLatitude Pixelation of a sphere], <ref name="[[:Template:Gorski2005]]">[http://iopscience.iop.org/0004-637X/622/2/759/pdf/0004-637X_622_2_759.pdf '''HEALPix: A Framework for High-Resolution Discretization and Fast Analysis of Data Distributed on the Sphere'''], K. M. G&oacute;rski, E. Hivon, A. J. Banday, B. D. Wandelt, F. K. Hansen, M. Reinecke, M. Bartelmann, ApJ, '''622''', 759-771, (2005). map, containing the analysis mask used in the lens reconstruction.
RLPP
This column contains the response function $R_L^{\phi\phi}$.
NLPP
This column contains a sky-averaged estimate of the noise power spectrum of PHIBAR. The noise is highly coloured. Note that there is some dependence of the noise power spectrum with the local noise level of the map. Note that the noise power spectrum estimate here is not sufficiently accurate for a power spectrum analysis.

[From Duncan Hanson, Feb.2013]

### Production process

The construction of these quantities are described in detail in Sec. 2.1 of P12_Lensing. This map has been band-limited between multipoles $10 \le L \le 2048$. The response function $R_L^{\phi\phi}$ here is analogous to the the beam transfer function in a CMBCosmic Microwave background temperature or polarization map. We have chosen to distribute this transfer-function convolved map rather than the normalized lens reconstruction as it is a significantly more localized function of the CMBCosmic Microwave background temperature map from which it is derived. This is discussed further in Appendix A of P12_Lensing.

### Inputs

This product is built from the 143 and 217 GHz Planck sky maps.

### File names and format

A single file named COM_CompMap_Lensing_2048_R1.10.fits with two BINTABLE extensions containing the items described above.

Column Name Data Type Units Description
1. EXTNAME = 'LENS-MAP' : Data columns
PHIBAR Real*4 none Map of the lensing potential
MASK Int none Region over which the lensing potential is reconstructed
PIXTYPE HEALPIX
COORDSYS GALACTIC Coordinate system
ORDERING NESTED Healpix ordering
NSIDE 2048 Healpix Nside
FIRSTPIX 0
LASTPIX 50331647
2. EXTNAME = 'TransFun'
RLPP Real*4 none Response function (see above)
NLPP Real*4 none sky-averaged noise spectrum
L_MIN 0
L_MAX 2048

The maps in Ext 1 are, as usual, in GALACTIC coordinates, Nside=2048 and in NESTED ordering. The vectors in Ext 2 run from $l_{min} = 0$ to $l_{max} =2028$.