FITS Headers
dmr_31b_imap_4yr.fits
Primary Header
SIMPLE = T / BITPIX = 16 / Number of bits per data pixel NAXIS = 0 / Number of data axes EXTEND = T / FITS data may contain extensions DATE = '2005-01-10' / Creation date (CCYY-MM-DD) of FITS header COMMENT FITS (Flexible Image Transport System) format is defined in 'Astronomy COMMENT and Astrophysics', volume 376, page 359; bibcode 2001A&A...376..359H TELESCOP= 'COBE ' / INSTRUME= 'DMR ' / OBJECT = 'ALL-SKY ' / COMMENT COMMENT This file contains the COBE-DMR 4-year sky map for the 31 GHz COMMENT channel B data. This map was produced by Tony Banday and Gary COMMENT Hinshaw in 1998 as follows. The final 4-year time-ordered COMMENT differential data archive was converted to a calibrated archive COMMENT in FITS format (the DMR 'CIO' data). The WMAP prototype map-making COMMENT software was adapted to the DMR experiment and used to generate COMMENT these maps using the HEALPix tessellation of the sky. As a check, COMMENT the same archive and code were used to generate maps in the COMMENT original COBE quad-cube pixelization. For the 31B channel (only) COMMENT the maps differ slightly from the officially released COBE-DMR maps COMMENT because of a difference in how the radiometer's magnetic COMMENT susceptibility correction was applied. In the original pipeline, COMMENT the correction involved three separate fit coefficients for three COMMENT separate time periods of usable data. For technical reasons, the COMMENT CIO-based pipeline used one fit coefficient for the correction of COMMENT all three time periods. Since the 31B channel has the least COMMENT weight of the 6 DMR channels, this difference should be of no COMMENT significant consequence. COMMENT CHAN_ID = '31B ' / FREQ = '31 GHz ' / REFERENC= 'C.L.Bennett, et.al., ApJL, 1996, 464, L1' / REFERENC= 'A. Kogut, et al., ApJ, 1996, 470, 653' / REFERENC= 'E.L. Wright, et al., ApJL, 1996, 458, L53' / REFERENC= 'K.M. Gorski, et al., astro-ph/0409513' / STOKES = 'INTENSITY' / EQUINOX = 2000.00 / SKYCOORD= 'GALACTIC' / PIXTYPE = 'HEALPIX ' / ORDERING= 'NESTED ' / RESOLUTN= 5 / NSIDE = 32 / NPIX = 12288 / FIRSTPIX= 0 / LASTPIX = 12287 / DATE-BEG= '22/12/1989' /Data set start date JSTART = '1989356000000000' /Start time YYYYDDDHHMMSSHHH DATE-END= '21/12/1993' /Data set start date JSTOP = '1993355235959000' /Stop time YYYYDDDHHMMSSHHH 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. END
Extension Header 2
XTENSION= 'BINTABLE' /binary table extension BITPIX = 8 /8-bit bytes NAXIS = 2 /2-dimensional binary table NAXIS1 = 8 /width of table in bytes NAXIS2 = 12288 /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 ' / TFORM1 = 'E ' /Real*4 (floating point) TUNIT1 = 'mK,thermodynamic' /physical unit of field TTYPE2 = 'N_OBS ' / TFORM2 = 'E ' /Real*4 (floating point) TUNIT2 = 'counts ' /physical unit of field PIXTYPE = 'HEALPIX ' /HEALPIX pixelisation ORDERING= 'NESTED ' /Pixel ordering scheme, either RING or NESTED OBJECT = 'FULLSKY ' / COORDSYS= 'G ' /Pixelization coordinate system NSIDE = 32 /Healpix resolution parameter NPIX = 12288 /Total number of pixels FIRSTPIX= 0 /First pixel # (0 based) LASTPIX = 12287 /Last pixel # (zero based) INDXSCHM= 'IMPLICIT' /indexing : IMPLICIT or EXPLICIT GRAIN = 0 /GRAIN = 0: No index, COMMENT G = Galactic, E = ecliptic, C = celestial = equatorial COMMENT GRAIN =1: 1 pixel index for each pixel, COMMENT GRAIN >1: 1 pixel index for Grain consecutive pixels END
