ACT Data Products - Weights AR1, AR2
These files contain combined hit-count maps for each pixel of Atacama Cosmology Telescope (ACT) maps of the southern and equatorial fields, observed during the 2008-2010 seasons, in the 148 GHz and 217 GHz bands, and produced for the ACT data release in February 2014. They are to be used with the associated sky map files, which use a cylindrical equal-area projection with a standard latitude of -53.5 degrees.
Each hit-count-map pixel represents the effective number of samples contributing to the correspondent sky map pixel. During mapping, the first and last few seconds of each timestream were windowed with a 1/2*(1-cos) taper to avoid ringing in the Fourier transforms when computing the noise model. This leads to non-integral values in the hit-count maps. The provided FITS file contain 18787 by 1177, 0.25 square arcminute pixels.
A complete description of the observations, data processing, calibration, instrument response, and mapmaking process which was used for this data release is in Dunner, et al, ApJ 762, 2013.