sdss_target_geometry.fits

This file is located at:

$VAGC_REDUX/sdss/sdss_target_geometry.fits

It describes the SDSS target geometry in terms of spherical polygons. This file can be read in using the 

read_fits_polygons

tool in idlutils.

The columns are:

  1. XCAPS[3,N]: directions for each cap (as specified in the mangle documentation)
  2. CMCAPS[N]: size of each cap (as specified in the mangle documentation)
  3. NCAPS: number of caps
  4. WEIGHT: weight assigned to each cap (ignore this)
  5. STR: area of each cap in steradians
  6. USE_CAPS: bitmask designating which caps to use
  7. RUN: SDSS drift scan run
  8. RERUN: processing rerun used for targeting
  9. CAMCOL: camera column
  10. FIELD: field in run
  11. TARGET_VERSION: version of target used in this region
  12. PHOTO_VERSION: version of photo used in this region
  13. STAR_GAL_MAGDIFF: star/galaxy psf-model difference used
  14. PET_MAG_LIMIT: Petrosian magnitude limit used
  15. PET_SB_LIMIT: Petrosian surface brightness limit used
  16. NMGYPERCOUNT[5]: calibration parameter (nano-maggies per count) used in targeting
  17. NMGYPERCOUNT_BEST[5]: calibration parameter which is our current best guess for this run
  18. RACEN: right ascension (J2000, deg) of geometric center for this field (not always inside the polygon!)
  19. DECCEN: right ascension (J2000, deg) of geometric center for this field (not always inside the polygon!)
  20. SCORE: photometric quality score assigned to this run/camcol/field by the Princeton reductions (between zero and one, higher is better; trust values below 0.5 very little)

It also has the following columns, which are from the tsField files documented at the Data Release web site.

  1. NOBJECTS
  2. NCHILD
  3. NSTARS
  4. NGALS
  5. FRAMES_STATUS
  6. PSP_STATUS
  7. STATUS
  8. CULLED
  9. BADMASK
  10. ACCEPTABLEMASK
  11. GOODMASK
  12. HOLEMASK
  13. SKY
  14. SKYSLOPE
  15. PSF_WIDTH

There is an ascii version of this file, stored in the files

$VAGC_REDUX/sdss/ascii/sdss_target_geometry.ply
$VAGC_REDUX/sdss/ascii/sdss_target_geometry_info.dat

The first file is the mangle-style description of the polygons. The second file stores the other pertinent information in the columns described above, in the format:

[run (1)] [rerun (2)] [camcol (3)] [field (4)] [nobjects (5)]
[nchild (6)] [nstars (7)] [ngals (8)] [sky_u (9)] [sky_g (10)] [sky_r (11)]
[sky_i (12)] [sky_z (13)] [skyslope_u (14)] [skyslope_g (15)]
[skyslope_r (16)] [skyslope_i (17)] [skyslope_z (18)] [psf_width_u (19)]
[psf_width_g (20)] [psf_width_r (21)] [psf_width_i (22)] [psf_width_z (23)]
[frames_status (24)] [psp_status (25)] [status_u (26)] [status_g (27)]
[status_r (28)] [status_i (29)] [status_z (30)] [culled (31)] [badmask (32)]
[acceptablemask (33)] [goodmask (34)] [holemask (35)] [target_version (36)]
[photo_version (37)] [star_gal_magdiff (38)] [pet_mag_limit (39)]
[pet_sb_limit (40)] [nmgypercount_u (41)] [nmgypercount_g (42)]
[nmgypercount_r (43)] [nmgypercount_i (44)] [nmgypercount_z (45)]
[nmgypercount_best_u (46)] [nmgypercount_best_g (47)]
[nmgypercount_best_r (48)] [nmgypercount_best_i (49)]
[nmgypercount_best_z (50)] [score (51)] [racen (52)] [deccen (53)]

where all of the columns appear on the same line for each field, and the number in parentheses indicates the (one-indexed) column number in the file.

NYU Value-Added Galaxy Catalog

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