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All-sky Galaxy catalogue

The purpose of this page is to make directly available the SuperCOSMOS all-sky galaxy catalogue, generated from scans of the UKST and POSS2 photographic Schmidt surveys and described in Peacock et al. (2016). This optical material was matched with WISE to produce the WISExSCOS photometric redshift catalogue.

What is released

  1. A table of objects to optical limits of B<21.5, R<20; this is deeper than the limits adopted in the WISExSCOS work, allowing users to vary the limit if desired. The columns are objID, ra, dec, Bmag, Bcal, Bcc, Rmag, Rcal, Rcc, Imag, Ical, Icc, Ebmv. The various magnitudes are observed (mag), adjusted for the slight hemispheric offset between photometric systems as described in Peacock et al. (cal); further corrected for extinction (cc).
  2. An additional table of objects that fill holes in the sky coverage left by calibration stepwedges on the plates. Mainly affecting POSS2 scans, these regions are omitted in the standard SSA database, although they can be accessed from the original SuperCOSMOS scans by using regions from an adjoining plate beyond the default central 5 x 5 degrees. The data in these regions is lower in quality, so we include only objects that paired up with WISE. The full SuperCOSMOS all-sky catalogue should be considered to consist of the main table plus these additional objects.
  3. A table of calibration properties for the photographic plates that are the basis for the catalogue. Columns are Field number, B-band linearity, zero point, slump coefficient (and same for R & I); the three coefficients are defined in equations 9 & 11 of Peacock et al. (2016). The plate-centre positions of the UKST and POSS2 plates are listed in and The POSS2 field numbers have been increased by 1000, in order to have a unique number over the whole sky. This information may be used if desired to mask out plates of lower depth as diagnosed by the zero point.


Download Link Size Description
SCOS_XSC_mCl1_B21.5_R20_noStepWedges.csv.gz 8,194,174,484 bytes, 241,341,816 rows all-sky galaxy catalogue
SCOS_stepWedges_inWISE.csv.gz 4,077,451 bytes, 124,344 rows catalogue from step-wedge regions
calib_master.dat 192,000 bytes, 2000 rows field calibration parameters

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