These files contain estimated Fourier-domain noise power spectral density (PSD) functions for South Pole Telescope (SPT) maps of the ra5h30dec-55 field observed during the 2008 season in the 150 GHz and 220 GHz bands, produced for the first SPT data release in December 2011. They are to be used with the associated map files, which use the oblique Lambert equal-area azimuthal projection.
The PSDs are constructed using the jackknife noise estimation technique (J. Sayers et al. 2009 ApJ 690 1597). The units of the PSDs are K and not K^2. The PSDs are presented as a 3120-pixel by 3120-pixel Fourier-domain grid, where the grid in each dimension corresponds to 0, 2pi/(NT), 2*2pi/(NT), ... (N/2-1)*2pi/(NT), 2pi/(2T), -(N/2-1)*2pi/(NT), ..., -2pi/(NT) where N is the number of elements (3120) and T is the sampling interval in each dimension of the map (0.25 arcminutes).
Each file contains the PSD estimated for a subregion of the map covering approximately one-ninth of the map area. The PSDs are stored in the primary image arrays of FITS files. The two numerical tags in the file names (as well as the X_CEN/Y_CEN and RA_CEN/DEC_CEN keywords in the files) refer to the pixel locations in x and y at the center of the mask used to define the subregion.
A complete description of the observations, data processing, calibration, instrument response, and mapmaking process for this data release is in Schaffer et al. 2011, ApJ, 743, 90.