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2dFGRS Final Data Release Photometric Catalogues |
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These ASCII text catalogues are provided for the convenience of users of the 2dFGRS Final Data Release. However it is important to note that the mSQL database is the definitive data source, and contains all the information in the ASCII text catalogues and much additional data. 1. Input photometric catalogues (source catalogues) The photometric catalogues (ngp.cat, sgp.cat and ran.cat for the NGP, SGP and random fields) have been derived from APM scans of the Southern Sky Survey (see Colless et al. 2001). The catalogues are highly complete down to their nominal limit at an extinction-corrected magnitude (BJSEL) of approximately bJ=19.45; this limit varies slightly from field to field, as described in detail by the survey masks. All sources in the photometric catalogues have a unique serial number (serial=SEQNUM), running from 1 to 389713, which is the primary database key. There are 382323 sources in these catalogues; the 7390 missing serial numbers correspond to sources rejected as artifacts on the basis of visual examination of their images, as detailed in the description of the 2dFGRS database. Each line of these catalogues contains the following parameters:
Keyword Format Description
SEQNUM I6 Assigned sequence number to this object; determines the
FITS filename (SEQNUM.fits)
ra A11 R.A. (B1950) in HH MM SS.SS
dec A11 Dec. (B1950) in DD MM SS.S
BJSEL F6.3 Final bj magnitude with extinction correction (i.e.
with corrections for isophote, field-effects and
plate-matching, then calibrated to total mags with
saturation correction, and then extinction corrected)
PROB F6.1 psi classification parameter:
for eyeballed galaxies
psi*1000 = (10000 + abs(jon) + psi*100)
for eyeballed non-galaxies
psi*1000 = -(10000 + abs(jon) + psi*100)
PARK F5.3 k classification parameter = k / k_star
PARMU F5.3 mu classification parameter = mu / mu_star
IGAL I2 Final classification
-4 = noise
-3 = star + star
-2 = star + fuzz
-1 = star
0 = galaxy + star merger
1 = galaxy
2 = galaxy + galaxy merger
JON I2 Eyeball classification, value > 0 only for galaxies
brighter than about 18th mag:
0 = noise
1 = S0
2 = elliptical
3 = spiral
4 = irregular
5 = undetermined galaxy
6 = star
7 = star + star merger
8 = galaxy + star merger
9 = galaxy + galaxy merger
ORIENT F5.1 Orientation measured in degrees clockwise from E to W:
orient = 180/pi * atan(2*sxy/((sxx + syy)*(1 + e)-syy))
ECCENT F5.3 Eccentricity (e)
e*200 = 200*(((sxx-syy)**2 + 4sxy**2)**0.5)/(sxx + syy)
AREA F6.0 Isophotal area in pixels
X_BJ F8.1 Plate x_bj in 8 micron pixels
Y_BJ F8.1 Plate y_bj in 8 micron pixels
DX F5.0 Distortion corrected difference (x_bj - x_R)*100
DY F5.0 Distortion corrected difference (y_bj - y_R)*100
BJG F6.3 Final bj magnitude without extinction correction
RMAG F5.2 Unmatched APM 'total' mag
PMAG F5.2 Unmatched raw APM profile integrated mag
FMAG F5.2 Unmatched raw APM 2" profile integrated mag
SMAG F5.2 Unmatched raw stellar mag (from APMCAL)
REDMAG F5.2 Not used
IFIELD I3 UKST field
IGFIELD I6 Galaxy number in UKST field
NAME A10 2dFGRS assigned name; if either (i) BJSELOLD is fainter
than 19.45, or (ii) the object could not be allocated to
a fibre by the configuration algorithm, then NAME is blank
BJG_OLD F5.2 Original bj magnitude without extinction correction
(prior to re-calibration to BJG)
BJSELOLD F5.2 Original bj magnitude with extinction correction
(prior to re-calibration to BJSEL); used to select
survey sample
100_BJG F5.2 100k release bj magnitude without extinction correction
(prior to re-calibration to BJG)
100BJSEL F5.2 100k release bj magnitude with extinction correction
(prior to re-calibration to BJSEL)
Note that there are three pairs of APM bJ magnitudes in each file, the pairs being with and without the extinction correction. Each of these three pairs correspond to progressive refinements of the photometric calibrations. The original calibration used to select the 2dFGRS sample corresponds to BJG_OLD and BJSELOLD; the calibration used for the 100k release corresponds to 100_BJG and 100BJSEL; the final, and best, calibration corresponds to BJG and BJSEL. The latter are the magnitudes that should in general be used; the original magnitudes are useful in understanding the original selection of the sample; the 100k magnitudes are useful for comparing analyses based on the two data releases. 2. Deleted source lists The objects deleted from the final source catalogues on the basis of visual inspection during a first pass at the time the catalogues were constructed are listed in deleted_pass1.cat. The objects deleted from the final source catalogues on the basis of visual inspection during a second pass based on a comparison of the APM and SuperCosmos source parameters are listed in deleted_pass2.cat. These files have the same format as the source catalogues. Details of the procedure are given in the description of the database. The objects in these lists are not in the final source catalogues. 3. Tile centres The centres of all the 2dFGRS tiles are listed in centres.ngp, centres.sgp and centres.ran. These files list R.A. and Dec. (B1950, in decimal degrees), tile number, tile name, and R.A. and Dec. (B1950, in HH MM SS.SS -DD MM SS.S). |