ABOUT LAMBDA

FITS Headers

DMR_SKYMAP_GALACTIC_90A_4YR.FITS

Primary Header

SIMPLE  =                    T / file does conform to FITS standard             
BITPIX  =                   32 / 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 defined in Astronomy and
COMMENT   Astrophysics Supplement Series v44/p363, v44/p371, v73/p359, v73/p365.
COMMENT   Contact the NASA Science Office of Standards and Technology for the   
COMMENT   FITS Definition document #100 and other FITS information.             
DATE    = '01/09/95'           / FITS file creation date (dd/mm/yy)             
COMMENT      FITS optional reserved keywords:                                   
DATE-MAP= '20/10/94'           /  Date when the sky maps were created           
ORIGIN  = 'CDAC    '           /  NASA Cosmology Data Analysis Center           
TELESCOP= 'COBE    '           /  Cosmic Background Explorer                    
INSTRUME= 'DMR     '           /  Differential Microwave Radiometers            
OBJECT  = 'ALL-SKY '           /                                                
EQUINOX =               2000.0 /                                                
REFERENC= 'C.L.Bennett, et al., 1995, COBE Preprint 95-04.' /                   
COMMENT     Other related references:                                           
COMMENT     'C.L.Bennett, et al., 1994, APJ, 436, 423.'                         
COMMENT     'G.F.Smoot, et al., 1992, APJ, 396, L1.'                            
COMMENT     'C.L.Bennett, et al., 1992, APJ, 396, L7.'                          
COMMENT     'E.L.Wright, et al., 1992, APJ, 396, L13.'                          
COMMENT     'A.Kogut, et al., 1992, APJ, 401, 1.'                               
COMMENT     'C.L.Bennett, et al., 1992, APJ, 391, 466.'                         
COMMENT     'G.F.Smoot, et al., 1990, APJ, 360, 685.'                           
COMMENT     'M.A.Janssen and S.Gulkis, 1992, in "The Infrared and Submillimeter 
COMMENT      Sky after COBE", eds. M.Signore and C.Dupraz (Dordrecht: Kluwer).' 
COMMENT     COBE/DMR specific keywords:                                         
CHAN_ID = '90A     '           /  DMR Channel name                              
COMMENT     Channel name is one of 31A, 31B, 53A, 53B, 90A, or 90B              
COMMENT     The thermodynamic and antenna temperature scales are related by     
COMMENT     a frequency-dependent factor corresponding to the deviation of the  
COMMENT     Rayleigh-Jeans law from the Planck function.  See DMR calibration   
COMMENT     paper (Bennett et.al., 1992, APJ, 391, 466) for details.            
TEMPTYPE= 'ANTENNA '           /  Scale used for temperature fields,            
COMMENT                        / one of 'ANTENNA ' or 'THERMO  '                
PLNCKCOR=             1.225941 /  Thermodynamic temperature =                   
COMMENT                        /   PLNCKCOR * antenna temperature               
FREQ    =              9.0E+10 /  Frequency in Hz at which data were taken      
COMMENT                        / Also used to define conversion from antenna    
COMMENT                        / to thermodynamic temperature                   
MAP_TYPE= 'SOLVED  '           /  Map derives from sparse matrix solution       
COORDSYS= 'G       '           /  Pixelization coordinate system                
COMMENT     Coordinate system is one of E = Ecliptic, G = Galactic,             
COMMENT     C = Celestial, i.e. Equatorial, or S = Special                      
PIXRESOL=                    6 /  Quad tree pixel resolution                    
DATE-BEG= '22/12/89'           /  Data set start date                           
JSTART  = '89356000000000'     /  Start time YYDDDHHMMSSHHH                     
DATE-END= '21/12/93'           /  Data set stop date                            
JSTOP   = '93355235959000'     /  Stop time YYDDDHHMMSSHHH                      
COMMENT     DATE-BEG and DATE-END give the date during which                    
COMMENT     the earliest and the latest data used in this product               
COMMENT     were obtained.                                                      
COMMENT     JSTART and JSTOP delimit in a form expected by COBE software        
COMMENT     the interval of time during which the data used                     
COMMENT     in this product were obtained.                                      
BASELINE= 'MEAN    '           /  Baseline used                                 
RMS_NOML=            40.307106 /  Nominal rms noise level (mK in 0.5 sec)       
RMS_FLGT=            39.097411 /  Flight rms noise level (from Chi-squared)     
CHI_SQ  =           0.94087681 /  Chi-squared value per degree of freedom       
B_DOT_M =           0.00008841 /  B*M value per degree of freedom               
S_DOT_S =           0.94096521 /  S*S value per degree of freedom               
COMMENT     Chi-squared is an approximation to SUM (S - T)**2/RMS_NOML**2       
COMMENT     where S is the calibrated, corrected measurement,                   
COMMENT     T is the predicted measurement based on sky temperature pattern     
COMMENT     and couplings to systematic error model functions,                  
COMMENT     and RMS_NOML is the nominal RMS.                                    
COMMENT     See the references, especially Janssen and Gulkis, for details.     
COMMENT     Analogously, S*S is SUM S**2/RMS_NOML**2 and B*M is the dot product 
COMMENT     between the measurement vector and the solution skymap.             
COMMENT     CHI_SQ   = S*S - B*M                                                
COMMENT     RMS_FLGT = RMS_NOML*SQRT(CHI_SQ)                                    
D_O_F   =            218386136 /  Total degree of freedom                       
TOT_OBS =            218398620 /  Total number of observations                  
COMMENT                        / i.e. number of data points used                
COMMENT                        / in calculation of this map                     
SUM_OBS =            436797240 /  Sum of number of observations field           
COMMENT                        / for each pixel in this map                     
COMMENT     For SOLVED maps SUM_OBS = 2*TOT_OBS because each observation        
COMMENT     is attributed to two pixels.  For COADDED maps there is no          
COMMENT     direct relation between the two.                                    
ECLIPSE =                    T /  If "T", eclipse data are included             
COR_MAGS=                    T /  If "T", magnetic susceptibility corrected     
COR_MEMO=                    T /  If "T", LIA memory corrected                  
COR_ECLI=                    T /  If "T", eclipse effect corrected              
COR_EART=                    F /  If "T", Earth limb corrected                  
COR_MOON=                    T /  If "T", Moon corrected                        
COR_MARS=                    T /  If "T", Mars corrected                        
COR_JUPI=                    T /  If "T", Jupiter corrected                     
COR_SATU=                    T /  If "T", Saturn corrected                      
VEL_SUN =                    T /  If "T", Sun velocity corrected                
VEL_EART=                    T /  If "T", Earth velocity corrected              
VEL_COBE=                    T /  If "T", satellite velocity corrected          
COMMENT                                                                         
COMMENT                                                                         
COMMENT     The following vector defines the dipole which has been removed      
COMMENT     from this dataset ("sun velocity correction").  The purpose of      
COMMENT     this correction is to minimize the gradient over a pixel due        
COMMENT     to the dipole; this vector is neither a definitive DMR value        
COMMENT     for the dipole nor the best fit dipole derived from this dataset.   
COMMENT     To restore the dipole to the SIGNAL for each pixel add the dot      
COMMENT     product of this vector with the pointing for the pixel.             
COMMENT     The vector is in mK antenna temperature in Ecliptic coordinates.    
DIP_MAG =             2.737677 /  Magnitude in mK antenna                       
COMMENT                        / of value used to remove dipole                 
DIP_ELON=             171.8793 /  Ecliptic longitude in degrees                 
COMMENT                        / of value used to remove dipole                 
DIP_ELAT=            -11.67802 /  Ecliptic latitude in degrees                  
COMMENT                        / of value used to remove dipole                 
END                                                                             

DMR_SKYMAP

XTENSION= 'BINTABLE'           / Extension type is Binary Table                 
BITPIX  =                    8 / Binary data                                    
NAXIS   =                    2 / Data are in a table                            
NAXIS1  =                   40 / Number of 8 bit bytes in each row              
NAXIS2  =                 6144 / Number of rows                                 
PCOUNT  =                    0 / Number of bytes of data following table        
GCOUNT  =                    1 / Group count (always 1 for bintable extensions) 
TFIELDS =                   10 / Number of fields (columns) in the table        
COMMENT     DMR Project Data Set FITS Skymap                                    
COMMENT                                                                         
EXTNAME = 'DMR_SKYMAP'         /  name of this binary table extension           
COMMENT                                                                         
COMMENT     Pixel number                                                        
TFORM1  = '1J      '           /  data format of the field: 4-byte INTEGER      
TTYPE1  = 'PIXEL   '           /  entire fieldname = PIXEL                      
TUNIT1  = '        '           /                                                
COMMENT                                                                         
COMMENT     Antenna temperature for this pixel in mK                            
TFORM2  = '1E      '           /  data format of the field: 4-byte REAL         
TTYPE2  = 'SIGNAL  '           /  entire fieldname = SIGNAL                     
TUNIT2  = 'mK      '           /  physical unit of field                        
COMMENT                                                                         
COMMENT     Number of observations for this pixel                               
TFORM3  = '1J      '           /  data format of the field: 4-byte INTEGER      
TTYPE3  = 'N_OBS   '           /  entire fieldname = N_OBS                      
TUNIT3  = '        '           /                                                
COMMENT                                                                         
COMMENT     Estimated pixel uncertainty                                         
COMMENT     as RMS_FLGT/SQRT(N_OBS)                                             
TFORM4  = '1E      '           /  data format of the field: 4-byte REAL         
TTYPE4  = 'SERROR  '           /  entire fieldname = SERROR                     
TUNIT4  = 'mK      '           /  physical unit of field                        
COMMENT                                                                         
COMMENT     The following geometric quantities refer to the nominal             
COMMENT     pixel center, not the average of actual lines of sight.             
COMMENT                                                                         
COMMENT     Ecliptic longitude of pixel center in degrees    (0, 360)           
TFORM5  = '1E      '           /  data format of the field: 4-byte REAL         
TTYPE5  = 'ECLON   '           /  entire fieldname = ECLON                      
TUNIT5  = 'DEGREES '           /  physical unit of field                        
COMMENT                                                                         
COMMENT     Ecliptic latitude of pixel center in degrees     (-90, 90)          
TFORM6  = '1E      '           /  data format of the field: 4-byte REAL         
TTYPE6  = 'ECLAT   '           /  entire fieldname = ECLAT                      
TUNIT6  = 'DEGREES '           /  physical unit of field                        
COMMENT                                                                         
COMMENT     Galactic longitude of pixel center in degrees    (0, 360)           
TFORM7  = '1E      '           /  data format of the field: 4-byte REAL         
TTYPE7  = 'GALON   '           /  entire fieldname = GALON                      
TUNIT7  = 'DEGREES '           /  physical unit of field                        
COMMENT                                                                         
COMMENT     Galactic latitude of pixel center in degrees     (-90, 90)          
TFORM8  = '1E      '           /  data format of the field: 4-byte REAL         
TTYPE8  = 'GALAT   '           /  entire fieldname = GALAT                      
TUNIT8  = 'DEGREES '           /  physical unit of field                        
COMMENT                                                                         
COMMENT     Right ascension of pixel center in degrees       (0, 360)           
TFORM9  = '1E      '           /  data format of the field: 4-byte REAL         
TTYPE9  = 'RA      '           /  entire fieldname = RA                         
TUNIT9  = 'DEGREES '           /  physical unit of field                        
COMMENT                                                                         
COMMENT     Declination of pixel center in degrees           (-90, 90)          
TFORM10 = '1E      '           /  data format of the field: 4-byte REAL         
TTYPE10 = 'DEC     '           /  entire fieldname = DEC                        
TUNIT10 = 'DEGREES '           /  physical unit of field                        
COMMENT                                                                         
END                                                                             

A service of the HEASARC and of the Astrophysics Science Division at NASA/GSFC
Goddard Space Flight Center, National Aeronautics and Space Administration
HEASARC Director: Dr. Alan P. Smale
LAMBDA Director: Dr. Eric R. Switzer
NASA Official: Dr. Eric R. Switzer
Web Curator: Mr. Michael R. Greason