B 
Name  Schema Table  Database  Description  Type  Length  Unit  Default Value  Unified Content Descriptor 
b 
CurrentAstrometry 
WSACalib 
Galactic latitude of device centre 
float 
8 
Degrees 

pos.galactic.lat 
b 
CurrentAstrometry 
WSATransit 
Galactic latitude of device centre 
float 
8 
Degrees 

pos.galactic.lat 
b 
CurrentAstrometry 
WSAUHS 
Galactic latitude of device centre 
float 
8 
Degrees 

pos.galactic.lat 
b 
CurrentAstrometry, PreviousAstrometry 
WSA 
Galactic latitude of device centre 
float 
8 
Degrees 

pos.galactic.lat 
b 
ObjectThin 
PS1DR2 
Galactic latitude. 
float 
8 
degrees 
999 

b 
dxsDetection, dxsJKsource, dxsSource, gcsDetection, gcsPointSource, gcsSource, gcsZYJHKsource, gpsDetection, gpsJHKsource, gpsPointSource, gpsSource, lasDetection, lasExtendedSource, lasPointSource, lasSource, lasYJHKsource, reliableDxsSource, reliableGcsPointSource, reliableGpsPointSource, reliableLasPointSource, reliableUdsSource, UKIDSSDetection, udsDetection, udsSource 
WSA 
Galactic latitude 
float 
8 
Degrees 

POS_GAL_LAT 
b 
calDetection, calSource, calSynopticSource 
WSACalib 
Galactic latitude 
float 
8 
Degrees 

POS_GAL_LAT 
b 
gaia_source 
GAIADR2 
Galactic latitude 
float 
8 
degrees 

pos.galactic.lat 
b 
gaia_source 
GAIAEDR3 
Galactic latitude 
float 
8 
degrees 

pos.galactic.lat 
b 
gaia_source, tgas_source 
GAIADR1 
Galactic latitude 
float 
8 
degrees 

pos.galactic.lat 
b 
glimpse1_hrc, glimpse1_mca, glimpse2_hrc, glimpse2_mca, glimpse_hrc_inter, glimpse_mca_inter 
GLIMPSE 
Galactic latitude 
float 
8 
degrees 

POS_GAL_LAT 
b 
lasMapRemeasAver, lasMapRemeasurement 
WSA 
Galactic latitude 
float 
8 
Degrees 

pos.galactic.lat 
b 
lasYselJSourceRemeasurement 
WSA 
Galactic latitude of aperture 
float 
8 
Degrees 

pos.galactic.lat 
b 
ptsDetection 
WSATransit 
Galactic latitude 
float 
8 
Degrees 

POS_GAL_LAT 
b 
twompzPhotoz 
TWOMPZ 
Galactic latitude {image primary HDU keyword: GAL_LAT} 
float 
8 
Degrees 

pos.galactic.lat 
b 
uhsDetection, uhsDetectionAll, uhsSource, uhsSourceAll 
WSAUHS 
Galactic latitude 
float 
8 
Degrees 

POS_GAL_LAT 
b 
wiseScosPhotoz, wiseScosPhotozRejects 
WISExSCOSPZ 
Galactic latitude computed from ra,dec {image primary HDU keyword: bGal} 
float 
8 
Degrees 

pos.galactic.lat 
B1 
mgcGalaxyStruct 
MGC 
Background correction applied to A1 
real 
4 

99.99 

B2 
mgcGalaxyStruct 
MGC 
Background correction applied to A2 
real 
4 

99.99 

B3 
mgcGalaxyStruct 
MGC 
Background correction applied to A3 
real 
4 

99.99 

B4 
mgcGalaxyStruct 
MGC 
Background correction applied to A4 
real 
4 

99.99 

b_err 
glimpse1_hrc, glimpse1_mca, glimpse2_hrc, glimpse2_mca, glimpse_hrc_inter, glimpse_mca_inter 
GLIMPSE 
Error in Galactic latitude 
float 
8 
arcsec 

ERROR 
B_IMAGE 
mgcDetection 
MGC 
Flux rms along minor axis 
real 
4 
pixel 


b_m_opt 
twomass_psc 
2MASS 
Blue magnitude of associated optical source. 
real 
4 
mag 

SPECT_FLUX_VALUE 
B_MGC 
mgcDetection 
MGC 
Best of MAG_AUTO and MAG_ISOCOR 
real 
4 
mag 


B_MGC_DC 
mgcDetection 
MGC 
B_MGC corrected for extinction 
real 
4 
mag 


b_v 
hipparcos_new_reduction 
GAIADR1 
BV colour index 
float 
8 
mag 

phot.color;em.opt.B;em.opt.V 
BACK 
mgcGalaxyStruct 
MGC 
Background Level (digital units) 
real 
4 

99.99 

backAlgo 
RequiredMosaicTopLevel 
WSAUHS 
Algorithm/code used for background subtraction 
varchar 
16 



BACKGRND 
mgcDetection 
MGC 
Background at object position 
real 
4 
count 


BACKm 
mgcGalaxyStruct 
MGC 
Background Level error () 
real 
4 

99.99 

BACKp 
mgcGalaxyStruct 
MGC 
Background Level error (+) 
real 
4 

99.99 

bandMergingCriterion 
Programme 
WSA 
maximum timespan over which different filters are merged into sources in the synoptic source table. 
real 
4 
minutes 
0.9999995e9 

bandMergingCriterion 
Programme 
WSACalib 
maximum timespan over which different filters are merged into sources in the synoptic source table. 
real 
4 
minutes 
0.9999995e9 

bandMergingCriterion 
Programme 
WSATransit 
maximum timespan over which different filters are merged into sources in the synoptic source table. 
real 
4 
minutes 
0.9999995e9 

bandMergingCriterion 
Programme 
WSAUHS 
maximum timespan over which different filters are merged into sources in the synoptic source table. 
real 
4 
minutes 
0.9999995e9 

batchID 
ObjectThin 
PS1DR2 
Internal database batch identifier. 
bigint 
8 


meta.id 
BBDWEIGHT 
mgcGalaxyStruct 
MGC 
Weight from MGC4 BBD 
real 
4 



BBDWEIGHTERR 
mgcGalaxyStruct 
MGC 
Error in weight from MGC4 BBD 
real 
4 



bCalCorr 
twompzPhotoz 
TWOMPZ 
SuperCOSMOS BgCorMag corrected for Galactic dust extinction. Southern hemisphere [dec(1950)<2.5] have been corrected for a small colour dependent offset between UKST and POSSII. {image primary HDU keyword: BcalCorr} 
real 
4 

0.9999995e9 

bCalCorr 
wiseScosPhotoz, wiseScosPhotozRejects, wiseScosSvm 
WISExSCOSPZ 
SuperCOSMOS BgCorMag corrected for Galactic dust extinction. Southern hemisphere [dec(1950)<2.5] have been corrected for a small colour dependent offset between UKST and POSSII. {image primary HDU keyword: Bcc} 
real 
4 

0.9999995e9 

bCalCorrErr 
twompzPhotoz 
TWOMPZ 
Estimated error in B band {image primary HDU keyword: errB} 
real 
4 
mag 
0.9999995e9 

bCalCorrErr 
wiseScosSvm 
WISExSCOSPZ 
Error on SuperCOSMOS BgCorMag corrected for Galactic dust extinction {image primary HDU keyword: errB} 
real 
4 

0.9999995e9 

beamNS 
Multiframe 
WSA 
Topend: NS beam {image primary HDU keyword: NSBEAM} 
real 
4 

0.9999995e9 

beamNS 
Multiframe 
WSACalib 
Topend: NS beam {image primary HDU keyword: NSBEAM} 
real 
4 

0.9999995e9 

beamNS 
Multiframe 
WSATransit 
Topend: NS beam {image primary HDU keyword: NSBEAM} 
real 
4 

0.9999995e9 

beamNS 
Multiframe 
WSAUHS 
Topend: NS beam {image primary HDU keyword: NSBEAM} 
real 
4 

0.9999995e9 

beamWE 
Multiframe 
WSA 
Topend: WE beam {image primary HDU keyword: WEBEAM} 
real 
4 

0.9999995e9 

beamWE 
Multiframe 
WSACalib 
Topend: WE beam {image primary HDU keyword: WEBEAM} 
real 
4 

0.9999995e9 

beamWE 
Multiframe 
WSATransit 
Topend: WE beam {image primary HDU keyword: WEBEAM} 
real 
4 

0.9999995e9 

beamWE 
Multiframe 
WSAUHS 
Topend: WE beam {image primary HDU keyword: WEBEAM} 
real 
4 

0.9999995e9 

best_classification 
rrlyrae 
GAIADR1 
Best RR Lyrae classification estimate out of "RRC" and "RRAB" 
varchar 
4 


meta.code.class;src.class 
best_use_cntr 
allwise_sc 
WISE 
Cntr identification value of the source extraction that was selected as a candidate Catalog source in the duplicate resolution process for the group of associated sources that included this extraction. For the AllWISE Source Catalog, best_use_cntr = cntr. For the AllWISE Reject Table, best_use_cntr may be the cntr value of a corresponding source in the AllWISE Source Catalog. 
bigint 
8 



best_use_cntr 
wise_allskysc 
WISE 
Cntr identification value of the source extraction that was selected as a candidate Catalog source in the duplicate resolution process for the group of associated sources that included this extraction. For the AllSky Release Catalog, best_use_cntr = cntr. For the AllSky Reject Table, best_use_cntr may be the cntr value of a corresponding source in the AllSky Release Catalog. 
bigint 
8 

99999999 

BEST_Z 
mgcBrightSpec 
MGC 
Best redshift 
real 
4 



BEST_ZQUAL 
mgcBrightSpec 
MGC 
Quality of best redshift 
tinyint 
1 



bestDetection 
StackObjectAttributes, StackObjectThin 
PS1DR2 
Identifies if this row is the best detection. 
tinyint 
1 

255 

BESTTQZ_Z 
mgcBrightSpec 
MGC 
2qz redshift 
real 
4 



beta 
ObjectThin 
PS1DR2 
Ecliptic latitude. 
float 
8 
degrees 
999 

bgrCpsa 
rosat_bsc, rosat_fsc 
ROSAT 
background countrate, vignetting corrected 
real 
4 
counts/sec/arcmin**2 

INST_BACKGROUND 
BII 
twoxmm, twoxmm_v1_2, twoxmmi_dr3_v1_0, xmm3dr4 
XMM 
Galactic latitude of the detection in degrees corresponding to the (corrected) coordinates RA and DEC. 
float 
8 
degrees 


bitProcessingFlag 
MapFrameStatus 
WSA 
a bitwise processing flag bit 0 catalogue extraction, bit 1 table culled, bit 2 headers updated 
int 
4 

99999999 

bitProcessingFlag 
MapFrameStatus 
WSAUHS 
a bitwise processing flag bit 0 catalogue extraction, bit 1 table culled, bit 2 headers updated 
int 
4 

99999999 

bitsPerPix 
MultiframeDetector 
WSA 
Number of bits per data pixel, eg. +32 = 4 byte integers {image extension keyword: BITPIX} 
smallint 
2 
FITS bitpix 

meta.number 
bitsPerPix 
MultiframeDetector 
WSACalib 
Number of bits per data pixel, eg. +32 = 4 byte integers {image extension keyword: BITPIX} 
smallint 
2 
FITS bitpix 

meta.number 
bitsPerPix 
MultiframeDetector 
WSATransit 
Number of bits per data pixel, eg. +32 = 4 byte integers {image extension keyword: BITPIX} 
smallint 
2 
FITS bitpix 

meta.number 
bitsPerPix 
MultiframeDetector 
WSAUHS 
Number of bits per data pixel, eg. +32 = 4 byte integers {image extension keyword: BITPIX} 
smallint 
2 
FITS bitpix 

meta.number 
bl_flg 
twomass_psc 
2MASS 
Blend flag. 
varchar 
3 


CODE_MISC 
bl_flg 
twomass_sixx2_psc 
2MASS 
indicates # JHK components fit to source 
varchar 
3 



bl_sub_flg 
twomass_xsc 
2MASS 
blanked/subtracted src description flag. 
smallint 
2 


CODE_MISC 
blk_fac 
twomass_xsc 
2MASS 
LCSB blocking factor (1, 2, 4, 8). 
smallint 
2 


FIT_PARAM 
bMag 
ukirtFSstars 
WSA 
B band total magnitude 
real 
4 
mag 
0.9999995e9 
phot.mag 
bMag 
ukirtFSstars 
WSACalib 
B band total magnitude 
real 
4 
mag 
0.9999995e9 
phot.mag 
bMag 
ukirtFSstars 
WSAUHS 
B band total magnitude 
real 
4 
mag 
0.9999995e9 
phot.mag 
bp_g 
gaia_source 
GAIADR2 
BPG colour 
real 
4 
mag 

phot.colour 
bp_g 
gaia_source 
GAIAEDR3 
BPG colour 
real 
4 
mag 

phot.colour 
bp_mag_zero_point 
ext_phot_zero_point 
GAIADR1 
BP magnitude zero point 
float 
8 
mag 

phot.mag;arith.zp 
bp_mag_zero_point_error 
ext_phot_zero_point 
GAIADR1 
Uncertainty on BP magnitude zero point 
float 
8 
mag 

stat.error;phot.mag;arith.zp 
bp_rp 
gaia_source 
GAIADR2 
BPRP colour 
real 
4 
mag 

phot.colour 
bp_rp 
gaia_source 
GAIAEDR3 
BPRP colour 
real 
4 
mag 

phot.colour 
brAperMag1 
calSynopticSource 
WSACalib 
Extended source Br aperture corrected mag (1.0 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
brAperMag1Err 
calSynopticSource 
WSACalib 
Error in extended source Br mag (1.0 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
ERROR 
brAperMag2 
calSynopticSource 
WSACalib 
Extended source Br aperture corrected mag (1.4 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
brAperMag2Err 
calSynopticSource 
WSACalib 
Error in extended source Br mag (1.4 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
ERROR 
brAperMag3 
calSource 
WSACalib 
Default point/extended source Br aperture corrected mag (2.0 arcsec aperture diameter) If in doubt use this flux estimator 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
brAperMag3 
calSynopticSource 
WSACalib 
Default point/extended source Br aperture corrected mag (2.0 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
brAperMag3Err 
calSource, calSynopticSource 
WSACalib 
Error in default point/extended source Br mag (2.0 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
ERROR 
brAperMag4 
calSource, calSynopticSource 
WSACalib 
Extended source Br aperture corrected mag (2.8 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
brAperMag4Err 
calSource, calSynopticSource 
WSACalib 
Error in extended source Br mag (2.8 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
ERROR 
brAperMag5 
calSynopticSource 
WSACalib 
Extended source Br aperture corrected mag (4.0 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
brAperMag5Err 
calSynopticSource 
WSACalib 
Error in extended source Br mag (4.0 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
ERROR 
brAperMag6 
calSource 
WSACalib 
Extended source Br aperture corrected mag (5.7 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
brAperMag6Err 
calSource 
WSACalib 
Error in extended source Br mag (5.7 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
ERROR 
braStratAst 
calVarFrameSetInfo 
WSACalib 
Strateva parameter, a, in fit to astrometric rms vs magnitude in Br band, see Sesar et al. 2007. 
real 
4 

0.9999995e9 

The best fit solution to the expected RMS position around the mean for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. 
braStratPht 
calVarFrameSetInfo 
WSACalib 
Strateva parameter, a, in fit to photometric rms vs magnitude in Br band, see Sesar et al. 2007. 
real 
4 

0.9999995e9 

The best fit solution to the expected RMS brightness (in magnitudes) for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. This technique was used in Sesar et al. 2007, AJ, 134, 2236. 
brbestAper 
calVariability 
WSACalib 
Best aperture (16) for photometric statistics in the Br band 
int 
4 

9999 

Aperture magnitude (16) which gives the lowest RMS for the object. All apertures have the appropriate aperture correction. This can give better values in crowded regions than aperMag3 (see Irwin et al. 2007, MNRAS, 375, 1449) 
brbStratAst 
calVarFrameSetInfo 
WSACalib 
Strateva parameter, b, in fit to astrometric rms vs magnitude in Br band, see Sesar et al. 2007. 
real 
4 

0.9999995e9 

The best fit solution to the expected RMS position around the mean for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. 
brbStratPht 
calVarFrameSetInfo 
WSACalib 
Strateva parameter, b, in fit to photometric rms vs magnitude in Br band, see Sesar et al. 2007. 
real 
4 

0.9999995e9 

The best fit solution to the expected RMS brightness (in magnitudes) for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. This technique was used in Sesar et al. 2007, AJ, 134, 2236. 
brchiSqAst 
calVarFrameSetInfo 
WSACalib 
Goodness of fit of Strateva function to astrometric data in Br band 
real 
4 

0.9999995e9 

The best fit solution to the expected RMS position around the mean for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. 
brchiSqpd 
calVariability 
WSACalib 
Chi square (per degree of freedom) fit to data (mean and expected rms) 
real 
4 

0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
brchiSqPht 
calVarFrameSetInfo 
WSACalib 
Goodness of fit of Strateva function to photometric data in Br band 
real 
4 

0.9999995e9 

The best fit solution to the expected RMS brightness (in magnitudes) for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. This technique was used in Sesar et al. 2007, AJ, 134, 2236. 
brClass 
calSource, calSynopticSource 
WSACalib 
discrete image classification flag in Br 
smallint 
2 

9999 
CLASS_MISC 
brClassStat 
calSource, calSynopticSource 
WSACalib 
N(0,1) stellarnessofprofile statistic in Br 
real 
4 

0.9999995e9 
STAT_PROP 
brcStratAst 
calVarFrameSetInfo 
WSACalib 
Strateva parameter, c, in fit to astrometric rms vs magnitude in Br band, see Sesar et al. 2007. 
real 
4 

0.9999995e9 

The best fit solution to the expected RMS position around the mean for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. 
brcStratPht 
calVarFrameSetInfo 
WSACalib 
Strateva parameter, c, in fit to photometric rms vs magnitude in Br band, see Sesar et al. 2007. 
real 
4 

0.9999995e9 

The best fit solution to the expected RMS brightness (in magnitudes) for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. This technique was used in Sesar et al. 2007, AJ, 134, 2236. 
brDeblend 
calSource 
WSACalib 
placeholder flag indicating parent/child relation in Br 
int 
4 

99999999 
CODE_MISC 
This CASU pipeline processing source extraction flag is a placeholder only, and is always set to zero in all passbands in the merged source lists. If you need to know when a particular image detection is a component of a deblend or not, test bit 4 of attribute ppErrBits (see corresponding glossary entry) which is set by WFAU's postprocessing software based on testing the areal profiles aprof28 (these are set by CASU to 1 for deblended components, or positive values for nondeblended detections). We encode this in an information bit of ppErrBits for convenience when querying the merged source tables. 
brDeblend 
calSynopticSource 
WSACalib 
placeholder flag indicating parent/child relation in Br 
int 
4 

99999999 
CODE_MISC 
brEll 
calSource, calSynopticSource 
WSACalib 
1b/a, where a/b=semimajor/minor axes in Br 
real 
4 

0.9999995e9 
PHYS_ELLIPTICITY 
breNum 
calMergeLog, calSynopticMergeLog 
WSACalib 
the extension number of this Br frame 
tinyint 
1 


NUMBER 
brErrBits 
calSource, calSynopticSource 
WSACalib 
processing warning/error bitwise flags in Br 
int 
4 

99999999 
CODE_MISC 
Apparently not actually an error bit flag, but a count of the number of zero confidence pixels in the default (2 arcsec diameter) aperture. 
brEta 
calSource, calSynopticSource 
WSACalib 
Offset of Br detection from master position (+north/south) 
real 
4 
arcsec 
0.9999995e9 
POS_EQ_DEC_OFF 
When associating individual passband detections into merged sources, a generous (in terms of the positional uncertainties) pairing radius of 2.0 (UKIDSS LAS and GPS; UHS; also nonsurvey programmes) or 1.0 (UKIDSS GPS, DXS and UDS) arcseconds is used, the higher value enabling pairing of moving sources when epoch separations may be several years. Such a large association criterion can of course lead to spurious pairings in the merged sources lists (although note that between passband pairs, handshake pairing is done: both passbands must agree that the candidate pair is their nearest neighbour for the pair to propagate through into the merged source table). In order to help filter spurious pairings out, and assuming that large positional offsets between the different passband detections are not expected (e.g. because of source motion, or larger than usual positional uncertainties) then the attributes Xi and Eta can be used to filter any pairings with suspiciously large offsets in one or more bands. For example, for a clean sample of QSOs from the LAS, you might wish to insist that the offsets in the selected sample are all below 1 arcsecond: simply add WHERE clauses into the SQL sample selection script to exclude all Xi and Eta values larger than the threshold you want. NB: the master position is the position of the detection in the shortest passband in the set, rather than the ra/dec of the source as stored in source attributes of the same name. The former is used in the pairing process, while the latter is generally the optimally weighted mean position from an astrometric solution or other combinatorial process of all individual detection positions across the available passbands. 
brexpML 
calVarFrameSetInfo 
WSACalib 
Expected magnitude limit of frameSet in this in Br band. 
real 
4 

0.9999995e9 

The expected magnitude limit of an intermediate stack, based on the total exposure time. expML=Filter.oneSecML+1.25*log10(totalExpTime). Since different intermediate stacks can have different exposure times, the totalExpTime is the minimum, as long as the number of stacks with this minimum make up 10% of the total. This is a more conservative treatment than just taking the mean or median total exposure time. 
brExpRms 
calVariability 
WSACalib 
Rms calculated from polynomial fit to modal RMS as a function of magnitude in Br band 
real 
4 
mag 
0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
brGausig 
calSource, calSynopticSource 
WSACalib 
RMS of axes of ellipse fit in Br 
real 
4 
pixels 
0.9999995e9 
MORPH_PARAM 
brHallMag 
calSource 
WSACalib 
Total point source Br mag 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
brHallMagErr 
calSource 
WSACalib 
Error in total point source Br mag 
real 
4 
mag 
0.9999995e9 
ERROR 
brIntRms 
calVariability 
WSACalib 
Intrinsic rms in Brband 
real 
4 
mag 
0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
brisDefAst 
calVarFrameSetInfo 
WSACalib 
Use a default model for the astrometric noise in Br band. 
tinyint 
1 

0 

brisDefPht 
calVarFrameSetInfo 
WSACalib 
Use a default model for the photometric noise in Br band. 
tinyint 
1 

0 

brMagMAD 
calVariability 
WSACalib 
Median Absolute Deviation of Br magnitude 
real 
4 
mag 
0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
brMagRms 
calVariability 
WSACalib 
rms of Br magnitude 
real 
4 
mag 
0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
brmaxCadence 
calVariability 
WSACalib 
maximum gap between observations 
real 
4 
days 
0.9999995e9 

The observations are classified as good, flagged or missing. Flagged observations are ones where the object has a ppErrBit flag. Missing observations are observations of the part of the sky that include the position of the object, but had no detection. All the statistics are calculated from good observations. The cadence parameters give the minimum, median and maximum time between observations, which is useful to know if the data could be used to find a particular type of variable. 
brMaxMag 
calVariability 
WSACalib 
Maximum magnitude in Br band, of good detections 
real 
4 

0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
brmeanMag 
calVariability 
WSACalib 
Mean Br magnitude 
real 
4 
mag 
0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
brmedCadence 
calVariability 
WSACalib 
median gap between observations 
real 
4 
days 
0.9999995e9 

The observations are classified as good, flagged or missing. Flagged observations are ones where the object has a ppErrBit flag. Missing observations are observations of the part of the sky that include the position of the object, but had no detection. All the statistics are calculated from good observations. The cadence parameters give the minimum, median and maximum time between observations, which is useful to know if the data could be used to find a particular type of variable. 
brmedianMag 
calVariability 
WSACalib 
Median Br magnitude 
real 
4 
mag 
0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
brmfID 
calMergeLog, calSynopticMergeLog 
WSACalib 
the UID of the relevant Br multiframe 
bigint 
8 


ID_FRAME 
brminCadence 
calVariability 
WSACalib 
minimum gap between observations 
real 
4 
days 
0.9999995e9 

The observations are classified as good, flagged or missing. Flagged observations are ones where the object has a ppErrBit flag. Missing observations are observations of the part of the sky that include the position of the object, but had no detection. All the statistics are calculated from good observations. The cadence parameters give the minimum, median and maximum time between observations, which is useful to know if the data could be used to find a particular type of variable. 
brMinMag 
calVariability 
WSACalib 
Minimum magnitude in Br band, of good detections 
real 
4 

0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
brmkExt 
calSource 
WSACalib 
Extended source colour BrK (using aperMag3) 
real 
4 
mag 
0.9999995e9 
PHOT_COLOR 
Default colours from pairs of adjacent passbands within a given set (e.g. YJ, JH and HK for YJHK) are recorded in the merged source table for ease of querying and speedy querying via indexing of these attributes. Presently, the pointsource colours and extended source colours are computed from the aperture corrected AperMag3 fixed 2 arcsec aperture diameter measures (for consistent measurement across all passbands) and generally good signaltonoise. At some point in the future, this may be changed such that pointsource colours will be computed from the PSFfitted measures and extended source colours computed from the 2d Sersic model profile fits. 
brmkExtErr 
calSource 
WSACalib 
Error on extended source colour BrK 
real 
4 
mag 
0.9999995e9 
ERROR 
Default colours from pairs of adjacent passbands within a given set (e.g. YJ, JH and HK for YJHK) are recorded in the merged source table for ease of querying and speedy querying via indexing of these attributes. Presently, the pointsource colours and extended source colours are computed from the aperture corrected AperMag3 fixed 2 arcsec aperture diameter measures (for consistent measurement across all passbands) and generally good signaltonoise. At some point in the future, this may be changed such that pointsource colours will be computed from the PSFfitted measures and extended source colours computed from the 2d Sersic model profile fits. 
brmkPnt 
calSource, calSynopticSource 
WSACalib 
Point source colour BrK (using aperMag3) 
real 
4 
mag 
0.9999995e9 
PHOT_COLOR 
Default colours from pairs of adjacent passbands within a given set (e.g. YJ, JH and HK for YJHK) are recorded in the merged source table for ease of querying and speedy querying via indexing of these attributes. Presently, the pointsource colours and extended source colours are computed from the aperture corrected AperMag3 fixed 2 arcsec aperture diameter measures (for consistent measurement across all passbands) and generally good signaltonoise. At some point in the future, this may be changed such that pointsource colours will be computed from the PSFfitted measures and extended source colours computed from the 2d Sersic model profile fits. 
brmkPntErr 
calSource, calSynopticSource 
WSACalib 
Error on point source colour BrK 
real 
4 
mag 
0.9999995e9 
ERROR 
Default colours from pairs of adjacent passbands within a given set (e.g. YJ, JH and HK for YJHK) are recorded in the merged source table for ease of querying and speedy querying via indexing of these attributes. Presently, the pointsource colours and extended source colours are computed from the aperture corrected AperMag3 fixed 2 arcsec aperture diameter measures (for consistent measurement across all passbands) and generally good signaltonoise. At some point in the future, this may be changed such that pointsource colours will be computed from the PSFfitted measures and extended source colours computed from the 2d Sersic model profile fits. 
brndof 
calVariability 
WSACalib 
Number of degrees of freedom for chisquare 
smallint 
2 

9999 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
brnDofAst 
calVarFrameSetInfo 
WSACalib 
Number of degrees of freedom of astrometric fit in Br band. 
smallint 
2 

9999 

The best fit solution to the expected RMS position around the mean for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. 
brnDofPht 
calVarFrameSetInfo 
WSACalib 
Number of degrees of freedom of photometric fit in Br band. 
smallint 
2 

9999 

The best fit solution to the expected RMS brightness (in magnitudes) for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. This technique was used in Sesar et al. 2007, AJ, 134, 2236. 
brnFlaggedObs 
calVariability 
WSACalib 
Number of detections in Br band flagged as potentially spurious by calDetection.ppErrBits 
int 
4 

0 

The observations are classified as good, flagged or missing. Flagged observations are ones where the object has a ppErrBit flag. Missing observations are observations of the part of the sky that include the position of the object, but had no detection. All the statistics are calculated from good observations. The cadence parameters give the minimum, median and maximum time between observations, which is useful to know if the data could be used to find a particular type of variable. 
brnGoodObs 
calVariability 
WSACalib 
Number of good detections in Br band 
int 
4 

0 

The observations are classified as good, flagged or missing. Flagged observations are ones where the object has a ppErrBit flag. Missing observations are observations of the part of the sky that include the position of the object, but had no detection. All the statistics are calculated from good observations. The cadence parameters give the minimum, median and maximum time between observations, which is useful to know if the data could be used to find a particular type of variable. 
brNgt3sig 
calVariability 
WSACalib 
Number of good detections in Brband that are more than 3 sigma deviations 
smallint 
2 

9999 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
brnMissingObs 
calVariability 
WSACalib 
Number of Br band frames that this object should have been detected on and was not 
int 
4 

0 

The observations are classified as good, flagged or missing. Flagged observations are ones where the object has a ppErrBit flag. Missing observations are observations of the part of the sky that include the position of the object, but had no detection. All the statistics are calculated from good observations. The cadence parameters give the minimum, median and maximum time between observations, which is useful to know if the data could be used to find a particular type of variable. 
brPA 
calSource, calSynopticSource 
WSACalib 
ellipse fit celestial orientation in Br 
real 
4 
Degrees 
0.9999995e9 
POS_POSANG 
brPetroMag 
calSource 
WSACalib 
Extended source Br mag (Petrosian) 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
brPetroMagErr 
calSource 
WSACalib 
Error in extended source Br mag (Petrosian) 
real 
4 
mag 
0.9999995e9 
ERROR 
brppErrBits 
calSource, calSynopticSource 
WSACalib 
additional WFAU postprocessing error bits in Br 
int 
4 

0 
CODE_MISC 
Postprocessing error quality bit flags assigned (NB: from UKIDSS DR2 release onwards) in the WSA curation procedure for survey data. From least to most significant byte in the 4byte integer attribute byte 0 (bits 0 to 7) corresponds to information on generally innocuous conditions that are nonetheless potentially significant as regards the integrity of that detection; byte 1 (bits 8 to 15) corresponds to warnings; byte 2 (bits 16 to 23) corresponds to important warnings; and finally byte 3 (bits 24 to 31) corresponds to severe warnings: Byte  Bit  Detection quality issue  Threshold or bit mask  Applies to     Decimal  Hexadecimal   0  4  Deblended  16  0x00000010  All VDFS catalogues  0  6  Bad pixel(s) in default aperture  64  0x00000040  All VDFS catalogues  1  15  Source in poor flat field region  32768  0x00008000  All but mosaics  2  16  Close to saturated  65536  0x00010000  All VDFS catalogues (though deeps excluded prior to DR8)  2  17  Photometric calibration probably subject to systematic error  131072  0x00020000  GPS only  2  19  Possible crosstalk artefact/contamination  524288  0x00080000  All but GPS  2  22  Lies within a dither offset of the stacked frame boundary  4194304  0x00400000  All but mosaics  In this way, the higher the error quality bit flag value, the more likely it is that the detection is spurious. The decimal threshold (column 4) gives the minimum value of the quality flag for a detection having the given condition (since other bits in the flag may be set also; the corresponding hexadecimal value, where each digit corresponds to 4 bits in the flag, can be easier to compute when writing SQL queries to test for a given condition). For example, to exclude all K band sources in the LAS having any error quality condition other than informational ones, include a predicate ... AND kppErrBits ≤ 255. See the SQL Cookbook and other online pages for further information. 
brprobVar 
calVariability 
WSACalib 
Probability of variable from chisquare (and other data) 
real 
4 

0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
brPsfMag 
calSource 
WSACalib 
Point source profilefitted Br mag 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
brPsfMagErr 
calSource 
WSACalib 
Error in point source profilefitted Br mag 
real 
4 
mag 
0.9999995e9 
ERROR 
brSeqNum 
calSource, calSynopticSource 
WSACalib 
the running number of the Br detection 
int 
4 

99999999 
ID_NUMBER 
brSerMag2D 
calSource 
WSACalib 
Extended source Br mag (profilefitted) 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
brSerMag2DErr 
calSource 
WSACalib 
Error in extended source Br mag (profilefitted) 
real 
4 
mag 
0.9999995e9 
ERROR 
brskewness 
calVariability 
WSACalib 
Skewness in Br band (see Sesar et al. 2007) 
real 
4 

0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
brtotalPeriod 
calVariability 
WSACalib 
total period of observations (last obsfirst obs) 
real 
4 
days 
0.9999995e9 

The observations are classified as good, flagged or missing. Flagged observations are ones where the object has a ppErrBit flag. Missing observations are observations of the part of the sky that include the position of the object, but had no detection. All the statistics are calculated from good observations. The cadence parameters give the minimum, median and maximum time between observations, which is useful to know if the data could be used to find a particular type of variable. 
brVarClass 
calVariability 
WSACalib 
Classification of variability in this band 
smallint 
2 

9999 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
brXi 
calSource, calSynopticSource 
WSACalib 
Offset of Br detection from master position (+east/west) 
real 
4 
arcsec 
0.9999995e9 
POS_EQ_RA_OFF 
When associating individual passband detections into merged sources, a generous (in terms of the positional uncertainties) pairing radius of 2.0 (UKIDSS LAS and GPS; UHS; also nonsurvey programmes) or 1.0 (UKIDSS GPS, DXS and UDS) arcseconds is used, the higher value enabling pairing of moving sources when epoch separations may be several years. Such a large association criterion can of course lead to spurious pairings in the merged sources lists (although note that between passband pairs, handshake pairing is done: both passbands must agree that the candidate pair is their nearest neighbour for the pair to propagate through into the merged source table). In order to help filter spurious pairings out, and assuming that large positional offsets between the different passband detections are not expected (e.g. because of source motion, or larger than usual positional uncertainties) then the attributes Xi and Eta can be used to filter any pairings with suspiciously large offsets in one or more bands. For example, for a clean sample of QSOs from the LAS, you might wish to insist that the offsets in the selected sample are all below 1 arcsecond: simply add WHERE clauses into the SQL sample selection script to exclude all Xi and Eta values larger than the threshold you want. NB: the master position is the position of the detection in the shortest passband in the set, rather than the ra/dec of the source as stored in source attributes of the same name. The former is used in the pairing process, while the latter is generally the optimally weighted mean position from an astrometric solution or other combinatorial process of all individual detection positions across the available passbands. 
bt_mag 
tycho2 
GAIADR1 
Tycho2 BT magnitude 
real 
4 
mag 

phot.mag;em.opt.B 
BULGE_E 
mgcGalaxyStruct 
MGC 
Bulge Ellipticity 
real 
4 

99.99 

BULGE_Em 
mgcGalaxyStruct 
MGC 
Bulge Ellipticity error () 
real 
4 

99.99 

BULGE_Ep 
mgcGalaxyStruct 
MGC 
Bulge Ellipticity error (+) 
real 
4 

99.99 

BULGE_FRAC 
mgcGalaxyStruct 
MGC 
Bulge Fraction (0=pure disk) 
real 
4 

99.99 

BULGE_FRACm 
mgcGalaxyStruct 
MGC 
Bulge Fraction error () 
real 
4 

99.99 

BULGE_FRACp 
mgcGalaxyStruct 
MGC 
Bulge Fraction error (+) 
real 
4 

99.99 

BULGE_PA 
mgcGalaxyStruct 
MGC 
Bulge Position Angle 
real 
4 

99.99 

BULGE_PAm 
mgcGalaxyStruct 
MGC 
Bulge Position Angle error () 
real 
4 

99.99 

BULGE_PAp 
mgcGalaxyStruct 
MGC 
Bulge Position Angle error (+) 
real 
4 

99.99 

BULGE_RE 
mgcGalaxyStruct 
MGC 
Bulge Effective Radius 
real 
4 

99.99 

BULGE_REm 
mgcGalaxyStruct 
MGC 
Bulge Effective Radius error () 
real 
4 

99.99 

BULGE_REp 
mgcGalaxyStruct 
MGC 
Bulge Effective Radius error (+) 
real 
4 

99.99 
