WMAP Low Res. I,Q,U,S Sky Map
Per Differencing Assembly
Single Year
FITS Header Information

The data made available through this page has been updated. The most recent version of this data may be accessed through /product/map/current/

The maps are contained in a binary table containing TEMPERATURE, Q_POLARISATION, U_POLARISATION, 'SPUR_SIGNAL', and N_OBS columns. A second table is supplied that contains the noise covariance matrices of the polarization maps.

Primary Header

SIMPLE  =                    T /FITS format
BITPIX  =                   16 /Dummy primary header
NAXIS   =                    0 /No data is associated with this header
EXTEND  =                    T /Extensions may (will!) be present
RESOLUTN=                    4 /Resolution Index
PIXTYPE = 'HEALPIX '           /Pixel algorigthm
ORDERING= 'NESTED  '           /Ordering scheme
NSIDE   =                   16 /Resolution Parameter
NPIX    =                 3072 /Number of pixels
FIRSTPIX=                    0 /First pixel (0 based)
LASTPIX =                 3071 /Last pixel (0 based)
COMMENT This file contains WMAP Intensity, Polarization, and "Spurious"
COMMENT (I, Q, U, S) Res 4 skymaps for the differencing assembly indicated by
COMMENT the DA keyword.
COMMENT The first year of data went into the maps.
DATE    = '2006-02-23T23:31:58' /file creation date (YYYY-MM-DDThh:mm:ss UT)
TELESCOP= 'WMAP    '           /Wilkinson Microwave Anisotropy Probe
REFERENC= 'WMAP Explanatory Supplement:  http://lambda.gsfc.nasa.gov/' /
STOKES  = 'IQU     '           /
DA      = 'V1      '           /WMAP Differencing Assembly
FREQ    = 'V band  '           /Frequency band
RELEASE = 'DR2     '           /WMAP Release
END

Temperature and Polarization Map Table

XTENSION= 'BINTABLE'           /binary table extension
BITPIX  =                    8 /8-bit bytes
NAXIS   =                    2 /2-dimensional binary table
NAXIS1  =                   20 /width of table in bytes
NAXIS2  =                 3072 /number of rows in table
PCOUNT  =                    0 /size of special data area
GCOUNT  =                    1 /one data group (required keyword)
TFIELDS =                    5 /number of fields in each row
TTYPE1  = 'TEMPERATURE '       /label for field 1
TFORM1  = 'E       '           /data format of field: 4-byte REAL
TUNIT1  = 'mK      '           /physical unit of field 1
TTYPE2  = 'Q_POLARISATION '    /label for field 2
TFORM2  = 'E       '           /data format of field: 4-byte REAL
TUNIT2  = 'mK,thermodynamic'   /physical unit of field 2
TTYPE3  = 'U_POLARISATION '    /
TFORM3  = 'E       '           /
TUNIT3  = 'mK,thermodynamic'   /
TTYPE4  = 'SPUR_SIGNAL '       /
TFORM4  = 'E       '           /
TUNIT4  = 'mK,thermodynamic'   /
TTYPE5  = 'N_OBS   '           /
TFORM5  = 'E       '           /
TUNIT5  = 'counts  '           /
EXTNAME = 'Stokes Maps'        /
DATE    =                    0 /
PIXTYPE = 'HEALPIX '           /
ORDERING= 'NESTED  '           /
NSIDE   =                   16 /
FIRSTPIX=                    0 /
LASTPIX =                 3071 /
END

Noise Covariance Table

XTENSION= 'BINTABLE'           /binary table extension
BITPIX  =                    8 /8-bit bytes
NAXIS   =                    2 /2-dimensional binary table
NAXIS1  =                   28 /width of table in bytes
NAXIS2  =                 3072 /number of rows in table
PCOUNT  =                    0 /size of special data area
GCOUNT  =                    1 /one data group (required keyword)
TFIELDS =                    7 /number of fields in each row
TTYPE1  = 'N_OBS   '           /label for field 1
TFORM1  = 'E       '           /data format of field: 4-byte REAL
TUNIT1  = 'counts  '           /physical unit of field 1
TTYPE2  = 'M11     '           /label for field 2
TFORM2  = 'E       '           /data format of field: 4-byte REAL
TUNIT2  = 'counts  '           /physical unit of field 2
TTYPE3  = 'M12     '           /
TFORM3  = 'E       '           /
TUNIT3  = 'counts  '           /
TTYPE4  = 'M13     '           /
TFORM4  = 'E       '           /
TUNIT4  = 'counts  '           /
TTYPE5  = 'M23     '           /
TFORM5  = 'E       '           /
TUNIT5  = 'counts  '           /
TTYPE6  = 'M22     '           /
TFORM6  = 'E       '           /
TUNIT6  = 'counts  '           /
TTYPE7  = 'M33     '           /
TFORM7  = 'E       '           /
TUNIT7  = 'counts  '           /
EXTNAME = 'Weight Arrays'      /
DATE    =                    0 /
PIXTYPE = 'HEALPIX '           /
ORDERING= 'NESTED  '           /
NSIDE   =                   16 /
FIRSTPIX=                    0 /
LASTPIX =                 3071 /
COMMENT Weight arrays must be divided by a scaling factor sigma_0^2
COMMENT to provide a weight array in physical units (mK^-2).  See WMAP
COMMENT Explanatory Supplement.
END

More information concerning the contents of this file is available.