WMAP FITS Header

Primary Header

SIMPLE  =                    T / file does conform to FITS standard
BITPIX  =                    8 / number of bits per data pixel
NAXIS   =                    0 / number of data axes
EXTEND  =                    T / FITS dataset may contain extensions
COMMENT   FITS (Flexible Image Transport System) format is defined in 'Astronomy
COMMENT   and Astrophysics', volume 376, page 359; bibcode: 2001A&A...376..359H
DATE    = '2003-07-30T00:00:00' /file creation date (YYYY-MM-DDThh:mm:ss UT)
OBJECT  = 'ALL-SKY '           / Portion of sky given
COMMENT   This file defines the sky pixels excluded by the WMAP intensity masks
COMMENT   Kp0, Kp2, Kp4, Kp12, the map-making (data processing) mask, and the
COMMENT   point source mask.  If a pixel is excluded by a mask, then a unique
COMMENT   bit value is set.  Bit values are set as follows:
COMMENT         bit0   not used.
COMMENT         bit1   set if excluded by Kp0; bit value = 2
COMMENT         bit2   set if excluded by Kp2; bit value = 4
COMMENT         bit3   set if excluded by Kp4; bit value = 8
COMMENT         bit4   set if excluded by Kp12; bit value = 16
COMMENT         bit5   set if excluded by processing mask; bit value = 32
COMMENT         bit6   set if excluded by source mask; bit value = 64
COMMENT
COMMENT   The exclusion zone corresponding to a particular mask may be
COMMENT   reconstructed by performing a logical AND of the N_obs field (treated
COMMENT   as a byte variable) and the bit value set for that mask.  For example,
COMMENT   point source exclusion zones may be obtained using
COMMENT   src = (BYTE(N_obs) AND 64)/64.  To combine e.g. the Kp2 cut with the
COMMENT   point source cuts, first reconstruct the individual masks using the
COMMENT   logical AND described above, then perform a logical OR of the two in
COMMENT   order to obtain a composite exclusion map.  Note that these
COMMENT   exclusion zone masks set an excluded pixel's value to 1
COMMENT   whereas the convention used for the intensity masks products is to set
COMMENT   excluded pixels to 0.
COMMENT
COMMENT   See the WMAP Explanatory Supplement for further details.
REFERENC= 'WMAP Explanatory Supplement: http://lambda.gsfc.nasa.gov/
VERSION = 'PASS 1  '           / Internal MAP Version
RESOLUTN=                    9 / Resolution index
SKYCOORD= 'Galactic'           / Coordinate system
PIXTYPE = 'HEALPIX '           / Pixel algorithm
ORDERING= 'NESTED  '           / Ordering scheme
NSIDE   =                  512 / Resolution parameter
NPIX    =              3145728 / # of pixels
FIRSTPIX=                    0 / First pixel (0 based)
LASTPIX =              3145727 / Last pixel (0 based)
END

Archive Map Table

XTENSION= 'BINTABLE'           /binary table extension
BITPIX  =                    8 /8-bit bytes
NAXIS   =                    2 /2-dimensional binary table
NAXIS1  =                    8 /width of table in bytes
NAXIS2  =              3145728 /number of rows in table
PCOUNT  =                    0 /size of special data area
GCOUNT  =                    1 /one data group (required keyword)
TFIELDS =                    2 /number of fields in each row
TTYPE1  = 'TEMPERATURE'        /label for field   1
TFORM1  = '1E      '           /data format of field: 4-byte REAL
TUNIT1  = 'mK, thermodynamic'  /physical unit of field
TTYPE2  = 'N_OBS   '           /label for field   2
TFORM2  = '1E      '           /data format of field: 4-byte REAL
TUNIT2  = 'counts  '           /physical unit of field
EXTNAME = 'Archive Map Table'  /name of this binary table extension
DATE    = '2003-07-30T00:00:00' /Table creation date
PIXTYPE = 'HEALPIX '           /Pixel algorithm
ORDERING= 'NESTED  '           /Ordering scheme
NSIDE   =                  512 /Resolution parameter
FIRSTPIX=                    0 /First pixel (0 based)
LASTPIX =              3145727 /Last pixel (0 based)
COMMENT   The TEMPERATURE field is set to 0 for all pixels.
COMMENT   N_obs defines masks.
END