Name: spAtlas-pppp-mmmmm-fff.fit, where pppp is the spectroscopic plate number, mmmmm is the MJD of observation of the last exposure included in the spectro reduction, and fff is the fiber id.
Produced by: dp
Size: About 115 Kb per fiber, 107 Mb per plate.
There are 10 atlas images per file. The first 5 are u,g,r,i,z, for the best reduction. The second 5 are u,g,r,i,z for the target reduction. If the atlas image cannot be read for any reason, a dummy image of size 0,0 is placed into the fits file. If the object has run 0, as can happen for hot standars for example, the fits file may be empty.
SIMPLE = T BITPIX = 16 NAXIS = 2 NAXIS1 = 128 NAXIS2 = 148 BZERO = 3.27680000000000E+04 BSCALE = 1.00000000000000E+00 EXTEND = T VERSION = 'v5_3_53 ' DERV_VER= 'v8_15 ' ASTR_VER= 'v5_13 ' ASTRO_ID= '2002-09-19T13:40:11 27771' BIAS_ID = 'PS ' FRAME_ID= '2002-09-19T14:09:21 08329' KO_VER = 'devel ' PS_ID = '2002-09-18T15:17:24 15246 camCol 1' CREATIME= 'Thu Sep 19 19:12:28 2002 UTC' / The local time when this file was cre SEED = 93054723 / Seed for photo random number generato REF_BAND= 2 / index of band used for canonical cent RUN = 1907 / Imaging run number RERUN = 21 / Processing rerun number CAMCOL = 1 / Column in the imaging camera FIELD = 153 / Field sequence number DARK_VAR= '9.61 15.6025 1.8225 7.84 0.81' / Per-pixel variances at zero DN; DN^2 GAIN = '1.62 3.32 4.71 5.165 4.745' / Mean gains of amplifiers; e/DN SOFTBIAS= 1000 / software "bias" added to all DN ID = 24 / Object id, as in run-rerun-camcol-fie FILTER = 'u ' SKY = 'best ' / best= latest reduction, target= the i COMMENT = 'Target is useful to see why we did what we did' COMMENT = 'Best is often a better view of the object' PLATE = 266 / spectroscopic plate MJD = 51630 / 2400000-MJD of last spectroscopic obs FIBER = 327 / fiber id COMMENT = 'As in plate-mjd-fiber' MAPID = '0266-51615-01' / Mapping between targets and fibers us DATE = '2003-02-27' / date of file creation ORIGIN = 'SDSS@Fermilab' TELESCOP= 'SDSS 2.5m at Apache Point Observatory' INSTRUME= 'SDSS imaging camera' AUTHOR = 'Jim Annis' COMMENT = 'These atlas images have been extracted from' COMMENT = 'the standard FITS heap format that the SDSS' COMMENT = 'PHOTO pipeline produces.' END