DR4 s08-s16 Coadd Maps presented in Naess et al. 2020

Product Name
Coadd Maps


These maps are made by optimally co-adding:

  • ACT s08-s10 temperature maps made from data taken with the MBAC camera (publicly available on LAMBDA)
  • ACT s13-s16 temperature and polarization maps made from nighttime data taken with the ACTPol camera (presented in Aiola et al 2020 and Choi et al 2020)
  • Planck PR2 temperature and PR3 polarization maps (publicly available)

The procedure used to co-add these datasets in described in Naess et al 2020.

File naming


  • "datasets": datasets involved in the co-adding procedure [possible tags: act, act_planck]
  • "release": these maps are part of the DR4 data release, and versioning allows for future modifications of thise relase [possible tags: dr4.xy]
  • "season": ACT observation seasons [possible tags: s08s16]
  • "patch": survey patch [possible tags: AA]
  • "freq": frequency tag [possible tags: f090, f150]
  • "product": see below for list of released products

Available products

  • "map": observed I,Q,U Stokes components [uK]
  • "map_srcfree": observed I,Q,U Stokes components with signal from point sources subtracted [uK]
  • "ivar": I-I, Q-Q, U-U inverse-variance pixel weight [uK^-2]


  • These maps are released following the IAU polarization convention (POLCCONV='IAU' in FITS header).
  • Baseline software to handle these maps is Pixell (https://github.com/simonsobs/pixell).

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DR4 TILe-C Component Separated Maps presented in Madhavacheril et al. 2019

Product Name
Component Separated Maps


Version tag: v1.2.0

This file describes component separated maps from ACTPol + Planck. The algorithm is described in arxiv:1911.05717. Please cite this paper when using this map.


Since v1.1.1
The effective frequency for the CMB used in the beam-bandpass coupling calculation was changed from 148 GHz and 93 GHz to the respective values for each array.

Data maps

The main map products are:
where REGION can be "boss" or "deep56" corresponding to two distinct non-overlapping regions of the sky.

Beam transfer functions can be found in ancillary_products/window_functions/beams. You may not need to actually load and use those files, since we have convolved maps with no deprojection with a 1.6 arcmin Gaussian FWHM beam and any map with deprojection with a 2.4 arcmin Gaussian FWHM beam. Note however that the beam was applied in 2D Fourier space, although the difference with a spherical harmonic beam is negligible.

The full set of available products are (releated beams are provided in the beam section of the release):

CMB+kSZ maps
        Map:            tilec_single_tile_REGION_cmb{,_deprojects_comptony,_deprojects_cib}_map_v1.2.0_joint.fits
        Noise:          tilec_single_tile_REGION_cmb{,_deprojects_comptony,_deprojects_cib}_map_v1.2.0_joint_noise.fits
        Cross-noise:    tilec_single_tile_REGION_cmb{_deprojects_comptony,_deprojects_cib}_comptony_map_v1.2.0_joint_cross_noise.fits
        Weights:        tilec_single_tile_REGION_cmb{,_deprojects_comptony,_deprojects_cib}_map_v1.2.0_joint_$ARRAY_weight.fits
tSZ/Compton-Y maps
        Map:            tilec_single_tile_REGION_comptony{,_deprojects_cmb,_deprojects_cib}_map_v1.2.0_joint.fits
        Noise:          tilec_single_tile_REGION_comptony{,_deprojects_cmb,_deprojects_cib}_map_v1.2.0_joint_noise.fits
        Cross-noise:    tilec_single_tile_REGION_comptony{_deprojects_comptony,_deprojects_cib}_comptony_map_v1.2.0_joint_cross_noise.fits
        Weights:        tilec_single_tile_REGION_comptony{,_deprojects_cmb,_deprojects_cib}_map_v1.2.0_joint_$ARRAY_weight.fits

The modes in that map are only reliable for 20 < ell < Nyquist.

All maps are provided as FITS files in the CAR (Plate-Caree) projection. We recommend using the `pixell` library to work with these.

Notice that the map, noise, and weights come in options that do not deproject anything, or that deproject another component. The former probably should be your baseline, and the latter should be used for systematics tests since they are noisier.

'Map' is a FITS file with a 2D array and a WCS header. For information about the beams, see beam section.

'Noise' contains the 2D Fourier space total noise power spectrum from the ILC pipeline (this includes both signal and instrument noise). 'Cross-noise' is the total cross-power-spectrum of the standard map (no deprojection) with a particular choice of deprojection, as estimated by the ILC pipeline. This cross-power spectrum is useful as an input to filters used in CMB lensing reconstruction.

The 'Weights' FITS file contains the 2D Fourier space weight for each pixell corresponding to the array $ARRAY, which can be any of [p01,p02,p03,p04,p05,p06,p07,p08,d56_01,d56_02,d56_03,d56_04,d56_05,d56_06,boss_01,boss_02,boss_03,boss_04]. The names of these arrays correspond to maps in Table I of arxiv:1911.05717.

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DR4 Lensing Maps presented in Darwish et al. 2019

Product Name
Lensing Maps


Lensing maps are provided in two regions of the sky: Deep56 (D56) and BOSS North (BN).


  • 'data', for data maps
  • [act_planck/act]_dr4.01_[D56/BN]_lensing_kappa[_baseline/].fits, patch = D56 for deep56, BN for BOSS North; type = 'act' for ACT only maps, 'act_planck' for ACT+Planck with tSZ deprojected (which is the baseline).

All maps are provided as FITS files in the CAR (Plate-Caree) projection. We recommend using the `pixell` library to work with these.

The lensing maps have been divided by the mean of the square of the mask $w_2 = mean(mask**2)$. This number has to be multiplied back out if you want to use the local value of the lensing convergence in your analysis (e.g. when stacking). If you are doing a harmonic space analysis (e.g. a cross-spectrum), then the appropriate mask correction has to be applied. These corrections are described in the associated Jupyter notebook tutorials.

Please see arxiv:2004.01139 for additional details and cite it when using these maps.

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Goddard Space Flight Center, National Aeronautics and Space Administration
HEASARC Director: Dr. Alan P. Smale
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