Specially processed maps

Lensing map

Description

Here we present the minimum-variance (MV) lens reconstruction which forms the basis for the main results of P12_Lensing. This map is produced using a combination of the 143 and 217 GHz Planck maps on approximately 70% of the sky, and is the same map on which the Planck lensing likelihood is based.

We distribute:

PHIBAR
A (transfer-function convolved) map of the lensing potential, in NSIDE 2048 HEALPix RING format. It is obtained by convolving the lensing potential estimate $\hat{\phi}$ with the lensing response function $R_L^{\phi\phi}$. This map has been band-limited between multipoles $10 \le L \le 2048$.
This is a NSIDE = 2048 HEALPix map, containing the analysis mask used in the lens reconstruction. Note: the lensing map PHIBAR may take small but non-zero values inside the masked regions because it has been bandlimited.
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, $N_L^{\phi\phi}$. The noise is highly coloured. There is a weak dependence of the noise power spectrum with the local noise level of the map, discussed in Appendix A of P12_Lensing. Note that the noise power spectrum estimate here is not sufficiently accurate for a power spectrum analysis.

Production process

The construction PHIBAR, RLPP and NLPP are described in detail in Sec. 2.1 of P12_Lensing. The response function $R_L^{\phi\phi}$ here is analogous to the the beam transfer function in a CMB 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 CMB temperature map from which it is derived, and therefore more useful for cross-correlation studies.

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 estimate, convolved with RLPP
MASK Int none Region over which the lensing potential is reconstructed
Keywords
PIXTYPE HEALPIX
COORDSYS GALACTIC Coordinate system
ORDERING NESTED Healpix ordering
NSIDE 2048 Healpix Nside
FIRSTPIX 0
LASTPIX 50331647
2. EXTNAME = 'TransFun' : Data columns
RLPP Real*4 none Response function (see above)
NLPP Real*4 none Sky-averaged noise power spectrum estimate (see above)
Keywords
L_MIN 0
L_MAX 2048

(Hierarchical Equal Area isoLatitude Pixelation of a sphere, <ref name="Template:Gorski2005">HEALPix: A Framework for High-Resolution Discretization and Fast Analysis of Data Distributed on the Sphere, K. M. Górski, E. Hivon, A. J. Banday, B. D. Wandelt, F. K. Hansen, M. Reinecke, M. Bartelmann, ApJ, 622, 759-771, (2005).

Cosmic Microwave background