VULCAN Browser

Home | Browser | Access | Login | FreeSQL

Glossary of VULCAN attributes

This Glossary alphabetically lists all attributes used in the VULCANv20260525 database(s) held in the ASNIR. If you would like to have more information about the schema tables please use the VULCANv20260525 Schema Browser (other Browser versions).

A B C D E F G H I J K L M
N O P Q R S T U V W X Y Z

P

Name Schema Table Database Description Type Length Unit Default Value Unified Content Descriptor

p1 catwise_2020, catwise_prelim WISE P vector component 1 real 4 arcsec

p2 catwise_2020, catwise_prelim WISE P vector component 2 real 4 arcsec

pa_2mass allwise_sc WISE Position angle (degrees E of N) of the vector from the WISE source to the associated 2MASS PSC source. This column is "null" if there is no associated 2MASS PSC source. float 8 deg

pa_2mass wise_allskysc WISE Position angle (degrees E of N) of the vector from the WISE source to the associated 2MASS PSC source, default if there is no associated 2MASS PSC source. real 4 degrees -0.9999995e9

pa_2mass wise_prelimsc WISE Position angle (degrees E of N) of the vector from the WISE source to the associated 2MASS PSC source, default if there is no associated 2MASS PSC source real 4 degrees -0.9999995e9

pairingCriterion Programme VULCANiDR The pairing criterion for associating detections into merged sources real 4 Degrees ??

par_pm catwise_2020, catwise_prelim WISE parallax from PM desc-asce elon real 4 arcsec

par_pm is computed from the motion-solution positions, which are translated by WPHotpmc to the standard epoch (MJD0), so except for estimation errors, par_pm is the parallax; par_pm will be null unless km = 3.

par_pmSig catwise_2020, catwise_prelim WISE one-sigma uncertainty in par_pm real 4 arcsec

par_sigma catwise_2020, catwise_prelim WISE one-sigma uncertainty in par_stat real 4 arcsec

par_stat catwise_2020, catwise_prelim WISE parallax estimate from stationary solution real 4 arcsec

The par_stat column is computed by using the motion estimate to move the ascending stationary-solution position from the ascending effective observation epoch to that of the descending solution, then dividing the ecliptic longitude difference by 2; par_stat will be null unless ka = 3 AND km > 0 AND all W?mJDmin/max/mean values are non-null in both ascending and descending mdex files.

parallax gaia_source GAIADR3 Parallax float 8 milliarcsec pos.parallax

parallax_error gaia_source GAIADR3 Standard error of parallax real 4 milliarcsec stat.error;pos.parallax

parallax_over_error gaia_source GAIADR3 Parallax divided by standard error real 4 arith.ratio

parallax_pmdec_corr gaia_source GAIADR3 Correlation between parallax and proper motion in Declination real 4 stat.correlation;pos.parallax;pos.pm;pos.eq.dec

parallax_pmra_corr gaia_source GAIADR3 Correlation between parallax and proper motion in Right Ascension real 4 stat.correlation;pos.parallax;pos.pm;pos.eq.ra

parallax_pseudocolour_corr gaia_source GAIADR3 Correlation between parallax and pseudocolour real 4 stat.correlation;em.wavenumber;pos.parallax

pGalaxy allSkyNIRSource VULCANiDR Probability that the source is a galaxy real 4 stat.probability

Individual detection classifications are combined in the source merging process to produce a set of attributes for each merged source as follows. Presently, a basic classification table is defined that assigns reasonably accurate, self-consistent probability values for a given classification code:

Flag Meaning Probability (%)

Star Galaxy Noise Saturated

-9 Saturated 0.0 0.0 5.0 95.0

-3 Probable galaxy 25.0 70.0 5.0 0.0

-2 Probable star 70.0 25.0 5.0 0.0

-1 Star 90.0 5.0 5.0 0.0

0 Noise 5.0 5.0 90.0 0.0

+1 Galaxy 5.0 90.0 5.0 0.0

Then, each separately available classification is combined for a merged source using Bayesian classification rules, assuming each datum is independent:

P(class_k)=Π_iP(class_k)_i / Σ_kΠ_iP(class_k)_i
where class_k is one of star|galaxy|noise|saturated, and i denotes the i^th single detection passband measurement available (the non-zero entries are necessary for the independent measures method to work, since some cases might otherwise be mutually exclusive). For example, if an object is classed in J|H|K as -1|-2|+1 it would have merged classification probabilities of pStar=73.5%, pGalaxy=26.2%, pNoise=0.3% and pSaturated=0.0%. Decision thresholds for the resulting discrete classification flag mergedClass are 90% for definitive and 70% for probable; hence the above example would be classified (not unreasonably) as probably a star (mergedClass=-2). An additional decision rule enforces mergedClass=-9 (saturated) when any individual classification flag indicates saturation.

ph_qual allwise_sc WISE Photometric quality flag. Four character flag, one character per band [W1/W2/W3/W4], that provides a shorthand summary of the quality of the profile-fit photometry measurement in each band, as derived from the measurement signal-to-noise ratio. varchar 4

A - Source is detected in this band with a flux signal-to-noise ratio w?snr>10.

B - Source is detected in this band with a flux signal-to-noise ratio 3<w?snr<10.

C - Source is detected in this band with a flux signal-to-noise ratio 2<w?snr<3.

U - Upper limit on magnitude. Source measurement has w?snr<2. The profile-fit magnitude w?mpro is a 95% confidence upper limit.

X - A profile-fit measurement was not possible at this location in this band. The value of w?mpro and w?sigmpro will be "null" in this band.

Z - A profile-fit source flux measurement was made at this location, but the flux uncertainty could not be measured. The value of w?sigmpro will be "null" in this band. The value of w?mpro will be "null" if the measured flux, w?flux, is negative, but will not be "null" if the flux is positive. If a non-null magnitude is present, it corresponds to the true flux, and not the 95% confidence upper limit. This occurs for a small number of sources found in a narrow range of ecliptic longitude which were covered by a large number of saturated pixels from 3-Band Cryo single-exposures.

ph_qual twomass_psc TWOMASS Photometric quality flag. varchar 3 meta.code.qual

ph_qual twomass_sixx2_psc TWOMASS flag indicating photometric quality of source varchar 3

ph_qual wise_allskysc WISE Photometric quality flag.
Four character flag, one character per band [W1/W2/W3/W4], that provides a shorthand summary of the quality of the profile-fit photometry measurement in each band, as derived from the measurement signal-to-noise ratio. char 4

ph_qual wise_prelimsc WISE Photometric quality flag
Four character flag, one character per band [W1/W2/W3/W4], that provides a shorthand summary of the quality of the profile-fit photometry measurement in each band, as derived from the measurement signal-to-noise ratio char 4

phi_opt twomass_psc TWOMASS Position angle on the sky of the vector from the the associated optical source to the TWOMASS source position, in degrees East of North. smallint 2 degrees pos.posAng

phot_bp_mean_flux gaia_source GAIADR3 Integrated BP mean flux float 8 electrons/s phot.flux;stat.mean

phot_bp_mean_flux_error gaia_source GAIADR3 Standard error on the integrated BP mean flux real 4 electrons/s stat.error;phot.flux;stat.mean

phot_bp_mean_flux_over_error gaia_source GAIADR3 Integrated mean BP flux divided by its standard error real 4 arith.ratio

phot_bp_mean_mag gaia_source GAIADR3 Integrated BP mean magnitude real 4 mag phot.mag;stat.mean

phot_bp_n_blended_transits gaia_source GAIADR3 Number of BP blended transits smallint 2 meta.number

phot_bp_n_contaminated_transits gaia_source GAIADR3 Number of BP contaminated transits smallint 2 meta.number

phot_bp_n_obs gaia_source GAIADR3 Number of observations contributing to BP photometry smallint 2 meta.number

phot_bp_rp_excess_factor gaia_source GAIADR3 Combined BP and RP excess factor real 4 arith.factor;phot.flux;em.opt

phot_g_mean_flux gaia_source GAIADR3 G-band mean flux float 8 electrons/s phot.flux;stat.mean;em.opt

phot_g_mean_flux_error gaia_source GAIADR3 Error on G-band mean flux real 4 electrons/s stat.error;phot.flux;stat.mean;em.opt

phot_g_mean_flux_over_error gaia_source GAIADR3 G-band mean flux divided by its standard error real 4 arith.ratio

phot_g_mean_mag gaia_source GAIADR3 G-band mean magnitude real 4 mag phot.mag;stat.mean;em.opt

phot_g_n_obs gaia_source GAIADR3 Number of observations contributing to G band photometry smallint 2 meta.number

phot_proc_mode gaia_source GAIADR3 Photometry processing mode tinyint 1 meta.code

phot_rp_mean_flux gaia_source GAIADR3 Integrated RP mean flux float 8 electrons/s phot.flux;stat.mean

phot_rp_mean_flux_error gaia_source GAIADR3 Standard error on the integrated RP mean flux real 4 electrons/s stat.error;phot.flux;stat.mean

phot_rp_mean_flux_over_error gaia_source GAIADR3 Integrated mean RP flux divided by its standard error real 4 arith.ratio

phot_rp_mean_mag gaia_source GAIADR3 Integrated RP mean magnitude real 4 mag phot.mag;stat.mean

phot_rp_n_blended_transits gaia_source GAIADR3 Number of RP blended transits smallint 2 meta.number

phot_rp_n_contaminated_transits gaia_source GAIADR3 Number of RP contaminated transits smallint 2 meta.number

phot_rp_n_obs gaia_source GAIADR3 Number of observations contributing to RP photometry smallint 2 meta.number

phot_variable_flag gaia_source GAIADR3 Photometric variability flag char 16 meta.code;src.var

pltScale Detection PS1DR2 Local plate scale at this location. real 4 arcsec/pixel -999

pm gaia_source GAIADR3 Total proper motion real 4 milliarcsec/year pos.pm;pos.eq

pmcode allwise_sc WISE This is a five character string that encodes information about factors that impact the accuracy of the motion estimation. These include the original blend count, whether a blend-swap took place, and the distance in hundredths of an arcsecond between the non-motion position and the motion mean-observation-epoch position. This column is null if a motion solution was not attempted or a valid solution was not found. varchar 5

The format is NQDDD where N is the original blend count, Q is either "Y" or "N" for "yes" or "no" a blend-swap occurred (i.e., the original primary component was not the final primary component), and DDD is the radial distance between the non-motion and motion at mean-observation epoch positions in units of 0.01 arcsec, clipped at 999 (almost 10 arcsec).
For example, a well-behaved source that is not part of a blend and that has similar stationary and motion fit positions would have a pmcode value like "1N008". A source with a questionable motion estimate that is passively deblended (nb=2) and whose stationary-fit and motion position differ by a significant amount would have a pmcode value like "3Y234".

pmcode catwise_2020, catwise_prelim WISE quality of the PM solution varchar 5

PMDec catwise_2020, catwise_prelim WISE proper motion in dec real 4 arcsec/yr

pmdec allwise_sc WISE The apparent motion in declination estimated for this source. This column is null if the motion fit failed to converge or was not attempted. CAUTION: This is the total motion in declination, and not the proper motion. The apparent motion can be significantly affected by parallax for nearby objects. int 4 mas/year

pmdec gaia_source GAIADR3 Proper motion in Declination direction float 8 milliarcsec/year pos.pm;.pos.eq.dec

pmdec_error gaia_source GAIADR3 Error of proper motion in Declination direction real 4 milliarcsec/year stat.error;pos.pm;.pos.eq.dec

pmdec_pseudocolour_corr gaia_source GAIADR3 Correlation between proper motion in declination and pseudocolour real 4 stat.correlation;em.wavenumber;pos.pm;pos.eq.dec

PMRA catwise_2020, catwise_prelim WISE motion in ra real 4 arcsec/yr

pmra allwise_sc WISE The apparent motion in right ascension estimated for this source. This column is null if the motion fit failed to converge or was not attempted. CAUTION: This is the total motion in right ascension, and not the proper motion. The apparent motion can be significantly affected by parallax for nearby objects. int 4 mas/year

pmra gaia_source GAIADR3 Proper motion in Right Ascension direction float 8 milliarcsec/year pos.pm;.pos.eq.ra

pmra_error gaia_source GAIADR3 Error of proper motion in Right Ascension direction real 4 milliarcsec/year stat.error;pos.pm;.pos.eq.ra

pmra_pmdec_corr gaia_source GAIADR3 Correlation between proper motion in Right Ascension and proper motion in Declination real 4 stat.correlation;pos.pm;pos.eq.ra;pos.pm;pos.eq.dec

pmra_pseudocolour_corr gaia_source GAIADR3 Correlation between proper motion in right ascension and pseudocolour real 4 stat.correlation;em.wavenumber;pos.pm;pos.eq.ra

pmSource allSkyNIRFrameSetInfo VULCANiDR Table from which Proper Motion was taken varchar 32 NONE

pNoise allSkyNIRSource VULCANiDR Probability that the source is noise real 4 stat.probability

Individual detection classifications are combined in the source merging process to produce a set of attributes for each merged source as follows. Presently, a basic classification table is defined that assigns reasonably accurate, self-consistent probability values for a given classification code:

Flag Meaning Probability (%)

Star Galaxy Noise Saturated

-9 Saturated 0.0 0.0 5.0 95.0

-3 Probable galaxy 25.0 70.0 5.0 0.0

-2 Probable star 70.0 25.0 5.0 0.0

-1 Star 90.0 5.0 5.0 0.0

0 Noise 5.0 5.0 90.0 0.0

+1 Galaxy 5.0 90.0 5.0 0.0

Then, each separately available classification is combined for a merged source using Bayesian classification rules, assuming each datum is independent:

P(class_k)=Π_iP(class_k)_i / Σ_kΠ_iP(class_k)_i
where class_k is one of star|galaxy|noise|saturated, and i denotes the i^th single detection passband measurement available (the non-zero entries are necessary for the independent measures method to work, since some cases might otherwise be mutually exclusive). For example, if an object is classed in J|H|K as -1|-2|+1 it would have merged classification probabilities of pStar=73.5%, pGalaxy=26.2%, pNoise=0.3% and pSaturated=0.0%. Decision thresholds for the resulting discrete classification flag mergedClass are 90% for definitive and 70% for probable; hence the above example would be classified (not unreasonably) as probably a star (mergedClass=-2). An additional decision rule enforces mergedClass=-9 (saturated) when any individual classification flag indicates saturation.

posAngle Detection PS1DR2 Position angle (sky-to-chip) at this location. real 4 degrees -999

posAngle allSkyNIRFrameSetInfo VULCANiDR Orientation of image x-axis to N-S float 8 Degrees -0.9999995e9 pos.posAng

posAngleTolerance Programme VULCANiDR The position angle tolerance used when creating deep stacks and tiles real 4 Degrees -0.9999995e9 ??

posMeanChisq ObjectThin PS1DR2 Reduced chi squared value of mean position. real 4 -999 stat.stdev

primaryDetection StackObjectAttributes, StackObjectThin PS1DR2 Identifies if this row is the primary stack detection. tinyint 1 255

priOrSec allSkyNIRSource VULCANiDR Combined all sky seam code for a unique (=0) or duplicated (!=0) source (eg. flags overlap duplicates). bigint 8 -99999999 meta.code

processingFlag allSkyNIRFrameSetInfo VULCANiDR Sum of processing flags: components = 0 - no processing, 1 ingested source, 2 added pri/sec, 4 calibrated photometry, 8 calculated homogenous subset. tinyint 1

processingVersion Detection, StackObjectThin PS1DR2 Data release version. tinyint 1

processingVersion ObjectThin PS1DR2 Data release version. tinyint 1 meta.id;meta.software

programmeID Programme VULCANiDR UID of the archived programme coded as above int 4 meta.id

programmeID ProgrammeCurationHistory, ProgrammeTable, RequiredFilters, RequiredNeighbours VULCANiDR the unique programme ID int 4 meta.id

programmeID SurveyProgrammes VULCANiDR VSA assigned programme UID {image primary HDU keyword: PROJECT} int 4 -99999999 meta.id

programmeID allSkyNIRFrameSetInfo VULCANiDR UID of programme, unique over main VSA/WSA public surveys bigint 8 meta.id

projectionID ObjectThin PS1DR2 Projection cell identifier. smallint 2 -1 meta.id

projectionID StackObjectThin PS1DR2 Projection cell identifier. smallint 2 -1

proprietary Survey VULCANiDR Logical flag indicating whether a survey is proprietary or not (1=yes; 0=no) tinyint 1 ??

prox twomass_psc, twomass_xsc TWOMASS Proximity. real 4 arcsec pos.angDistance

pSaturated allSkyNIRSource VULCANiDR Probability that the source is saturated real 4 stat.probability

Individual detection classifications are combined in the source merging process to produce a set of attributes for each merged source as follows. Presently, a basic classification table is defined that assigns reasonably accurate, self-consistent probability values for a given classification code:

Flag Meaning Probability (%)

Star Galaxy Noise Saturated

-9 Saturated 0.0 0.0 5.0 95.0

-3 Probable galaxy 25.0 70.0 5.0 0.0

-2 Probable star 70.0 25.0 5.0 0.0

-1 Star 90.0 5.0 5.0 0.0

0 Noise 5.0 5.0 90.0 0.0

+1 Galaxy 5.0 90.0 5.0 0.0

Then, each separately available classification is combined for a merged source using Bayesian classification rules, assuming each datum is independent:

P(class_k)=Π_iP(class_k)_i / Σ_kΠ_iP(class_k)_i
where class_k is one of star|galaxy|noise|saturated, and i denotes the i^th single detection passband measurement available (the non-zero entries are necessary for the independent measures method to work, since some cases might otherwise be mutually exclusive). For example, if an object is classed in J|H|K as -1|-2|+1 it would have merged classification probabilities of pStar=73.5%, pGalaxy=26.2%, pNoise=0.3% and pSaturated=0.0%. Decision thresholds for the resulting discrete classification flag mergedClass are 90% for definitive and 70% for probable; hence the above example would be classified (not unreasonably) as probably a star (mergedClass=-2). An additional decision rule enforces mergedClass=-9 (saturated) when any individual classification flag indicates saturation.

pseudocolour gaia_source GAIADR3 Astrometrically determined pseudocolour of the source real 4 micron^-1 em.wavenumber

pseudocolour_error gaia_source GAIADR3 STandard error of the pseudocolour of the source real 4 micron^-1 em.wavenumber

psfChiSq Detection PS1DR2 Reduced chi squared value of the PSF model fit. real 4 -999

psfCore Detection PS1DR2 PSF core parameter k, where F = F0 / (1 + k r^2 + r^3.33). real 4 -999

psfFlux Detection PS1DR2 Flux from PSF fit. real 4 Janskys -999

psfFluxErr Detection PS1DR2 Error on flux from PSF fit. real 4 Janskys -999

psfLikelihood Detection PS1DR2 Likelihood that this detection is best fit by a PSF. real 4 -999

psfMajorFWHM Detection PS1DR2 PSF major axis FWHM. real 4 arcsec -999

psfMinorFWHM Detection PS1DR2 PSF minor axis FWHM. real 4 arcsec -999

psfQf Detection PS1DR2 PSF coverage factor. real 4 -999

psfQfPerfect Detection PS1DR2 PSF weighted fraction of pixels totally unmasked. real 4 -999

psfTheta Detection PS1DR2 PSF major axis orientation. real 4 degrees -999

pStar allSkyNIRSource VULCANiDR Probability that the source is a star real 4 stat.probability

Individual detection classifications are combined in the source merging process to produce a set of attributes for each merged source as follows. Presently, a basic classification table is defined that assigns reasonably accurate, self-consistent probability values for a given classification code:

Flag Meaning Probability (%)

Star Galaxy Noise Saturated

-9 Saturated 0.0 0.0 5.0 95.0

-3 Probable galaxy 25.0 70.0 5.0 0.0

-2 Probable star 70.0 25.0 5.0 0.0

-1 Star 90.0 5.0 5.0 0.0

0 Noise 5.0 5.0 90.0 0.0

+1 Galaxy 5.0 90.0 5.0 0.0

Then, each separately available classification is combined for a merged source using Bayesian classification rules, assuming each datum is independent:

P(class_k)=Π_iP(class_k)_i / Σ_kΠ_iP(class_k)_i
where class_k is one of star|galaxy|noise|saturated, and i denotes the i^th single detection passband measurement available (the non-zero entries are necessary for the independent measures method to work, since some cases might otherwise be mutually exclusive). For example, if an object is classed in J|H|K as -1|-2|+1 it would have merged classification probabilities of pStar=73.5%, pGalaxy=26.2%, pNoise=0.3% and pSaturated=0.0%. Decision thresholds for the resulting discrete classification flag mergedClass are 90% for definitive and 70% for probable; hence the above example would be classified (not unreasonably) as probably a star (mergedClass=-2). An additional decision rule enforces mergedClass=-9 (saturated) when any individual classification flag indicates saturation.

pts_key twomass_psc TWOMASS A unique identification number for the PSC source. int 4 meta.id

pts_key twomass_xsc TWOMASS key to point source data DB record. int 4 meta.id

publicDb Release VULCANiDR the name of the SQL Server database containing the public release varchar 128 NONE ??

pv21 CurrentAstrometry VULCANiDR Coefficient for r term (use only with ZPN projection) {image extension keyword: PV2_1}
transformation from pixel to celestial co-ordinates float 8 -0.9999995e9 stat.fit.param

pv22 CurrentAstrometry VULCANiDR Coefficient for r**2 term (use only with ZPN projection) {image extension keyword: PV2_2}
transformation from pixel to celestial co-ordinates float 8 -0.9999995e9 stat.fit.param

pv23 CurrentAstrometry VULCANiDR Coefficient for r**3 term (use only with ZPN projection) {image extension keyword: PV2_3}
transformation from pixel to celestial co-ordinates float 8 -0.9999995e9 stat.fit.param

pv24 CurrentAstrometry VULCANiDR Coefficient for r**4 term (use only with ZPN projection) {image extension keyword: PV2_4}
transformation from pixel to celestial co-ordinates float 8 -0.9999995e9 stat.fit.param

pv25 CurrentAstrometry VULCANiDR Coefficient for r**5 term (use only with ZPN projection) {image extension keyword: PV2_5}
transformation from pixel to celestial co-ordinates float 8 -0.9999995e9 stat.fit.param

pxcntr twomass_psc TWOMASS The pts_key value of the nearest source in the PSC. int 4 meta.number

pxcntr twomass_xsc TWOMASS ext_key value of nearest XSC source. int 4 meta.number

pxpa twomass_psc, twomass_xsc TWOMASS The position angle on the sky of the vector from the source to the nearest neighbor in the PSC, in degrees East of North. smallint 2 degrees pos.posAng

WFAU, Institute for Astronomy,
Royal Observatory, Blackford Hill
Edinburgh, EH9 3HJ, UK

vsa-support@roe.ac.uk
25/05/2026