Data published in

The 2dF QSO Redshift Survey - III. The Input Catalogue
R.J. Smith, S.M. Croom, B.J. Boyle, T. Shanks, L. Miller, N.S. Loaring, 2005, MNRAS, accepted

For the purposes of the 2dF QSO Redshift Survey (2QZ), we have created a catalogue of u, b_J, r magnitudes for 3 million stellar sources selected from photographic plates over 740 square degrees of high galactic lattitude sky. In the catalogues being released here, we are providing only source position (RA, dec, J2000) and three broad-band mangitudes (u, b_J, r). In addition to this full catalogue, we are releasing the input catalogue for the 2QZ. This is simply a subset to which colour cuts have been applied to select QSO candidates. More rigourous data quality checks have also been applied to this subset.

Before trying to use any of the data available on this page, please read through the full description of the data products and carefully consider the various advantages and limitations of the photographic techniques used here. A paper describing the data reduction and selection techniques in detail is available. (Smith, Croom et al, 2001, MNRAS, accepted).

Data are stored as thirty separate ASCII text files, one per UKST plate, containing RA, dec (J2000) expressed in radians, physical X,Y APM scan coordinates, b_J, u, and r magniudes in that order. Astrometry is based on the blue plate, so an object must be detected on this plate to appear in the catalogue. Large negative values (e.g. -9999) signify objects not detected in the U and R bands. In most cases, this failure to find a match is due to scan defects or confusion, but in some cases may be a genuine non detection. See Smith, Croom et al. (MNRAS, 2005, accepted) for a more detailed discussion. Note that these data are stored on a per plate basis and cover the full plate area, not just the central region used in the 2QZ survey. Many objects will appear twice; once each on adjascent plates. Also, all objects are included down to the plate limit, which will vary for different plates. Though the photometric sequences used for calibration allow calibration down to b_J=22, the photometric field flattening algorithm was only intended for b_J‹21 and no data integrity checks have been performed outside this range.

These data have all the selection criteria of the above catalogue, plus three colour cuts to select bluer than average objects and limited at b_J‹20·85. As above, data are stored in simple ASCII files, but the columns are, in order,
object name, RA (HH MM SS), dec (DD MM SS), plate name, physical X,Y APM scan coordinates, b_J, u-b_J, and b_J-r.
r band upper limits (i.e., non-detections on the r plate) are identified by storing the colour as b_J-r-10.


#  object name    HH MM SS.SS  DD MM SS.S   F       X         Y      bJ     u-bJ   bJ-r   
J214300.5-282548  21 43 00.52 -28 25 48.3  466  15931.89  -9573.50  20.63  -0.46   0.50
J214301.7-282036  21 43 01.72 -28 20 35.2  466  15915.12 -10157.07  20.76  -0.61   0.82
J214315.1-281901  21 43 15.14 -28 19 00.6  466  15589.04 -10340.24  20.30  -1.54   0.64
J214434.1-273515  21 44 34.12 -27 35 14.9  466  13736.12 -15266.40  20.42  -1.04 -10.75
J214256.1-281655  21 42 56.09 -28 16 54.7  466  16062.09 -10564.54  20.29  -0.28   0.39
J214312.4-281455  21 43 12.46 -28 14 54.3  466  15664.42 -10797.43  19.64  -0.54   0.34

Equatorial Strip, 23 290 objects, 2Mb (gzipped 715kb)
SGP Strip, 24 478 objects, 2.1Mb (gzipped 750kb)

The 2QZ team (Thu 19 Jun 2008 10:26:28 PDT by RJS)

This site is kindly hosted by Astrophysics Research Institute of Liverpool JMU