WMAP 'Foreground Cleaned' I Maps
(Q, V and W Differencing Assemblies)
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/

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    = '2003-06-25T00:00:00' /file creation date (YYYY-MM-DDThh:mm:ss UT)    
OBJECT  = 'ALL-SKY '           / Portion of sky given                           
COMMENT   This file contains the 'foreground-cleaned' sky map for the           
COMMENT   differencing assembly indicated by the keyword 'DA'.  This map was    
COMMENT   used in the generation of the WMAP first-year CMB power spectrum.     
COMMENT   The Galactic foreground signal was removed using the 5-parameter      
COMMENT   template fitting method described in Bennett et al. (2003).  Since    
COMMENT   these maps were generated early in the first-year analysis, prior to  
COMMENT   the final Galaxy modeling effort, the template coefficients used to   
COMMENT   clean this map are slightly different than the ones reported in       
COMMENT   Bennett et al. (2003).  The differences are of no consequence for     
COMMENT   cosmological applications.  Note that since the templates were fit    
COMMENT   only with data outside of the Kp2 mask, the foreground removal is not 
COMMENT   applicable to regions near the Galactic plane, where the spectrum of  
COMMENT   the Galactic emission is different.                                   
COMMENT                                                                         
COMMENT   See the WMAP Explanatory Supplement for further details.              
REFERENC= 'WMAP Explanatory Supplement: http://lambda.gsfc.nasa.gov/            
REFERENC= 'Bennett et al. 2003, First Year WMAP Observations: Foreground        
REFERENC= '  Emission, ApJ                                                      
VERSION = 'PASS 1  '           / Internal MAP Version                           
STARTGMT= '20012220000000000000' / Start time of TOD used                       
ENDGMT  = '20022212359000000000' / End time of TOD used                         
DA      = 'Q1      '           /Differencing Assembly                           
FREQ    = 'Q band  '           /Frequency band                                  
STOKES  = 'Intensity'          / i,q, or u                                      
RESOLUTN=                    9 / Resolution index                               
SKYCOORD= 'Galactic'           / Coordinate system                              
GALMASK = 'Kp2'                / Galaxy mask                                    
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                                                                             

Extension Header #1

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    = '2003-06-25T00:00:00' /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 in thermodynamic units                       
COMMENT   N_obs is the effective number of observations in the pixel            
END                                                                             

More information concerning the format of this file is available.