VOcabulary for the IVOA Unified Content Descriptors (Version wd-1.0, 2008-05-08)
Arithmetic quantities
arith
Q: means that the word can be used indifferently as first or secondary word
Difference between two quantities described by the same UCD
arith.diff
S: stands for only secondary: the word cannot be used as the first word to describe a single quantity
Numerical factor
arith.factor
P: means that the word can only be used as primary or first word
Gradient
arith.grad
Rate (per time unit)
arith.rate
Ratio between two quantities described by the same UCD
arith.ratio
Zero point
arith.zp
Electromagnetic spectrum
Channel / instrumental spectral bin coordinate (bin number)
em.bin
Energy value in the em frame
em.energy
Frequency value in the em frame
em.freq
Gamma rays part of the spectrum
em.gamma
Hard gamma ray (>500 keV)
em.gamma.hard
Soft gamma ray (120 - 500 keV)
em.gamma.soft
Infrared part of the spectrum
em.IR
Infrared between 15 and 30 micron
Infrared between 30 and 60 micron
Infrared between 3 and 4 micron
em.IR.3-4um
Infrared between 4 and 8 micron
em.IR.4-8um
Infrared between 60 and 100 micron
Infrared between 8 and 15 micron
em.IR.8-15um
Far-Infrared, 30-100 microns
em.IR.FIR
Infrared between 1.5 and 2 micron
em.IR.H
Infrared between 1.0 and 1.5 micron
em.IR.J
Infrared between 2 and 3 micron
em.IR.K
Medium-Infrared, 5-30 microns
em.IR.MIR
Near-Infrared, 1-5 microns
em.IR.NIR
Designation of major atomic lines
em.line
Bracket gamma line
em.line.Brgamma
CO radio line, e.g. 12CO(1-0) rest wl 115GHz
em.line.CO
H-alpha line
em.line.Halpha
H-beta line
em.line.Hbeta
H-delta line
em.line.Hdelta
H-gamma line
em.line.Hgamma
21cm hydrogen line
em.line.HI
H-Lyalpha line
em.line.Lyalpha
[OIII] line whose rest wl is 500.7 nm
em.line.OIII
Millimetric/submillimetric part of the spectrum
em.mm
Millimetric between 100 and 200 GHz
Millimetric between 1500 and 3000 GHz
Millimetric between 200 and 400 GHz
Millimetric between 30 and 50 GHz
Millimetric between 400 and 750 GHz
Millimetric between 50 and 100 GHz
Millimetric between 750 and 1500 GHz
Optical part of the spectrum
em.opt
Optical band between 400 and 500 nm
em.opt.B
Optical band between 750 and 1000 nm
em.opt.I
Optical band between 600 and 750 nm
em.opt.R
Optical band between 300 and 400 nm
em.opt.U
Optical band between 500 and 600 nm
em.opt.V
Radio part of the spectrum
em.radio
Radio between 100 and 200 MHz
Radio between 12 and 30 GHz
Radio between 1500 and 3000 MHz
Radio between 200 and 400 MHz
Radio between 20 and 100 MHz
Radio between 3 and 6 GHz
em.radio.3-6GHz
Radio between 400 and 750 MHz
Radio between 6 and 12 GHz
em.radio.6-12GHz
Radio between 750 and 1500 MHz
Ultraviolet part of the spectrum
em.UV
Ultraviolet between 100 and 200 nm
Ultraviolet between 10 and 50 nm
Ultraviolet between 200 and 300 nm
Ultraviolet between 50 and 100 nm
Far-Ultraviolet
em.UV.FUV
Wavenumber value in the em frame
em.wavenumber
Wavelength value in the em frame
em.wl
Central wavelength
em.wl.central
Effective wavelength
em.wl.effective
X-ray part of the spectrum
em.X-ray
Hard X-ray (12 - 120 keV)
em.X-ray.hard
Medium X-ray (2 - 12 keV)
em.X-ray.medium
Soft X-ray (0.12 - 2 keV)
em.X-ray.soft
Instrument
instr
Instrumental background
instr.background
E: means a photometric quantity, and can be followed by a word describing a part of the electromagnetic spectrum
Bandpass (e.g.: band name) of instrument
instr.bandpass
Bandwidth of the instrument
instr.bandwidth
Baseline for interferometry
instr.baseline
Beam
instr.beam
Calibration parameter
instr.calib
Detector
instr.det
Instrument noise
instr.det.noise
Point Spread Function
instr.det.psf
Quantum efficiency
instr.det.qe
Dispersion of a spectrograph
instr.dispersion
Filter
instr.filter
Field of view
instr.fov
Observatory, satellite, mission
instr.obsty
Seeing
instr.obsty.seeing
Offset angle respect to main direction of observation
instr.offset
Spectral order in a spectrograph
instr.order
Various instrumental parameters
instr.param
Pixel (default size: angular)
instr.pixel
Photographic plate
instr.plate
Plate emulsion
instr.plate.emulsion
Instrument precision
instr.precision
Instrument saturation threshold
instr.saturation
Instrument scale (for CCD, plate, image)
instr.scale
Instrument sensitivity, detection threshold
instr.sensitivity
Instrument configuration or setup
instr.setup
Sky level
instr.skyLevel
Sky temperature
instr.skyTemp
Telescope
instr.tel
Telescope focal length
instr.tel.focalLength
Metadata
meta
Abstract (of paper, proposal,etc.)
meta.abstract
Bibliographic reference
meta.bib
Author name
meta.bib.author
Bibcode
meta.bib.bibcode
Figure in a paper
meta.bib.fig
Journal name
meta.bib.journal
Page number
meta.bib.page
Volume number
meta.bib.volume
Code or flag
meta.code
Classification code
meta.code.class
limit uncertainty error flag
meta.code.error
Membership code
meta.code.member
MIME type
meta.code.mime
Multiplicity or binarity flag
meta.code.multip
Quality, precision, reliability flag or code
meta.code.qual
Status code (e.g.: status of a proposal/observation)
meta.code.status
Unknown or impossible to understand quantity
meta.cryptic
Identity of man/organization responsible for the data
meta.curation
Dataset
meta.dataset
Curation/contact e-mail
meta.email
File
meta.file
FITS standard
meta.fits
Identifier, name or designation
meta.id
Identifier of associated counterpart
meta.id.assoc
Name of Co-Investigator
meta.id.CoI
Cross identification
meta.id.cross
Identification of parent source
meta.id.parent
Part of identifier, suffix or sub-component
meta.id.part
Name of Principal Investigator
meta.id.PI
Main value of something
meta.main
Quantity was produced by a model
meta.modelled
Note or remark (longer than a code or flag)
meta.note
Number (of things; e.g. nb of object in an image)
meta.number
Record number
meta.record
Reference, or origin
meta.ref
IVORN, Int. VO Resource Name (ivo://)
meta.ref.ivorn
URI, universal resource identifier
meta.ref.uri
URL, web address
meta.ref.url
Software used in generating data
meta.software
Table or catalogue
meta.table
Title or explanation
meta.title
UCD
meta.ucd
Unit
meta.unit
Version
meta.version
Observation
obs
Airmass
obs.airMass
Atmosphere, atmospheric phenomena affecting an observation
obs.atmos
Atmospheric extinction
obs.atmos.extinction
Atmospheric refraction angle
obs.atmos.refractAngle
Calibration observation
obs.calib
Related to flat-field calibration observation (dome, sky, ..)
obs.calib.flat
Exposure
obs.exposure
Region covered by the observation
obs.field
Image
obs.image
Observer, discoverer
obs.observer
Various observation or reduction parameter
obs.param
Observation proposal
obs.proposal
Proposal cycle
obs.proposal.cycle
Sequence of observations, exposures or events
obs.sequence
Photometry
phot
Antenna temperature
phot.antennaTemp
Photometric calibration
phot.calib
Color index or magnitude difference
phot.color
C: is a colour index, and can be followed by two successive word describing a part of the electromagnetic spectrum
color excess
phot.color.excess
Dereddened color
phot.color.reddFree
Flux expressed in counts
phot.count
fluence
phot.fluence
Photon flux
phot.flux
Bolometric flux
phot.flux.bol
Flux density (per wl/freq/energy interval)
phot.flux.density
Flux density surface brightness
phot.flux.density.sb
Flux surface brightness
phot.flux.sb
Limb-darkening coefficients
phot.limbDark
Photometric magnitude
phot.mag
Bolometric correction
phot.mag.bc
Bolometric magnitude
phot.mag.bol
Distance modulus
phot.mag.distMod
Dereddened magnitude
phot.mag.reddFree
Surface brightness in magnitude units
phot.mag.sb
Physical quantities
phys
Extinction or absorption along the line of sight
phys.absorption
Absorption coefficient (e.g. in a spectral line)
phys.absorption.coeff
Galactic extinction
phys.absorption.gal
Optical depth
phys.absorption.opticalDepth
Abundance
phys.abund
Fe/H abundance
phys.abund.Fe
Hydrogen abundance
phys.abund.X
Helium abundance
phys.abund.Y
Metallicity abundance
phys.abund.Z
Acceleration
phys.acceleration
Albedo or reflectance
phys.albedo
Angular area
phys.angArea
Angular momentum
phys.angMomentum
Angular size width diameter dimension extension major minor axis extraction radius
phys.angSize
angular size extent or extension of semi-major axis
phys.angSize.smajAxis
angular size extent or extension of semi-minor axis
phys.angSize.sminAxis
Area (in linear units)
phys.area
Atomic and molecular physics (shared properties)
phys.atmol
Branching ratio
phys.atmol.branchingRatio
Related to collisions
phys.atmol.collisional
Collisional strength
phys.atmol.collStrength
Configuration
phys.atmol.configuration
Atomic / molecular cross-section
phys.atmol.crossSection
Element
phys.atmol.element
Atomic molecular excitation parameter
phys.atmol.excitation
Quantity refers to atomic/molecular final/ground state, level, ecc.
phys.atmol.final
Quantity refers to atomic/molecular initial state, level, ecc.
phys.atmol.initial
Related to ionization
phys.atmol.ionization
Ion, ionization stage
phys.atmol.ionStage
Lande factor
phys.atmol.lande
Atomic level
phys.atmol.level
Lifetime of a level
phys.atmol.lifetime
Line shifting coefficient
phys.atmol.lineShift
Atomic number Z
phys.atmol.number
Oscillator strength
phys.atmol.oscStrength
Parity
phys.atmol.parity
Quantum number
phys.atmol.qn
Type of radiation characterizing atomic lines (electric dipole/quadrupole, magnetic dipole)
phys.atmol.radiationType
Statistical weight
phys.atmol.sWeight
Statistical weight for nuclear spin states
phys.atmol.sWeight.nuclear
Type of nuclear spin symmetry
phys.atmol.symmetry
Atomic term
phys.atmol.term
Transition between states
phys.atmol.transition
Transition probability, Einstein A coefficient
phys.atmol.transProb
Atomic weight
phys.atmol.weight
Weighted oscillator strength
phys.atmol.wOscStrength
Column density
phys.columnDensity
Quantities related to composition of objects
phys.composition
Mass to light ratio
phys.composition.massLightRatio
Mass yield
phys.composition.yield
Related to cosmology
phys.cosmology
Generic damping quantities
phys.damping
Density (of mass, electron, ...)
phys.density
Complex dielectric function
phys.dielectric
Dispersion measure
phys.dispMeasure
Electric field
phys.electField
V: stands for vector. Such a word can be followed by another describing the axis or reference frame in which the measurement is done
Electron
phys.electron
Electron degeneracy parameter
phys.electron.degen
Emissivity
phys.emissivity
Emission measure
phys.emissMeasure
Energy
phys.energy
Energy-density
phys.energy.density
Entropy
phys.entropy
Equation of state
phys.eos
Excitation parameter U
phys.excitParam
Gaunt factor/correction
phys.gauntFactor
Gravity
phys.gravity
Ionization parameter
phys.ionizParam
Collisional ionization
phys.ionizParam.coll
Radiative ionization
phys.ionizParam.rad
Luminosity
phys.luminosity
Luminosity function
phys.luminosity.fun
Absolute magnitude
phys.magAbs
Bolometric absolute magnitude
phys.magAbs.bol
Magnetic field
phys.magField
Mass
phys.mass
Mass loss
phys.mass.loss
Molecular data
phys.mol
Molecular dipole
phys.mol.dipole
Molecular electric dipole moment
phys.mol.dipole.electric
Molecular magnetic dipole moment
phys.mol.dipole.magnetic
Molecular dissociation
phys.mol.dissociation
Formation heat for molecules
phys.mol.formationHeat
Molecular quadrupole
phys.mol.quadrupole
Molecular electric quadrupole moment
phys.mol.quadrupole.electric
Molecular rotation
phys.mol.rotation
Molecular vibration
phys.mol.vibration
Related to neutrino
phys.particle.neutrino
Polarization degree (or percentage)
phys.polarization
Circular polarization
phys.polarization.circular
Linear polarization
phys.polarization.linear
Rotation measure polarization
phys.polarization.rotMeasure
Stokes polarization
phys.polarization.stokes
Pressure
phys.pressure
Recombination coefficient
phys.recombination.coeff
Refraction index
phys.refractIndex
Star formation rate
phys.SFR
Linear size, length (not angular)
phys.size
Axis ratio (a/b) or (b/a)
phys.size.axisRatio
Linear diameter
phys.size.diameter
Linear radius
phys.size.radius
Linear semi major axis
phys.size.smajAxis
Linear semi minor axis
phys.size.sminAxis
Temperature
phys.temperature
Effective temperature
phys.temperature.effective
Electron temperature
phys.temperature.electron
Transmission (of filter, instrument, ...)
phys.transmission
Space velocity
phys.veloc
Angular velocity
phys.veloc.ang
Velocity dispersion
phys.veloc.dispersion
Escape velocity
phys.veloc.escape
Expansion velocity
phys.veloc.expansion
Microturbulence velocity
phys.veloc.microTurb
Orbital velocity
phys.veloc.orbital
Pulsational velocity
phys.veloc.pulsat
Rotational velocity
phys.veloc.rotat
Transverse / tangential velocity
phys.veloc.transverse
Related to virial quantities (mass, radius, ..)
phys.virial
Position and coordinates
pos
Angular distance, elongation
pos.angDistance
Angular resolution
pos.angResolution
Position in alt-azimutal frame
pos.az
Alt-azimutal altitude
pos.az.alt
Alt-azimutal azimut
pos.az.azi
Alt-azimutal zenith distance
pos.az.zd
Barycenter
pos.barycenter
Body related coordinates
pos.bodyrc
Body related coordinate (altitude on the body)
pos.bodyrc.alt
Body related coordinate (latitude on the body)
pos.bodyrc.lat
Body related coordinate (longitude on the body)
pos.bodyrc.long
Cartesian (rectangular) coordinates
pos.cartesian
Cartesian coordinate along the x-axis
pos.cartesian.x
Cartesian coordinate along the y-axis
pos.cartesian.y
Cartesian coordinate along the z-axis
pos.cartesian.z
Cosmic Microwave Background reference frame
pos.cmb
Direction cosine
pos.dirCos
Linear distance
pos.distance
Coordinates related to Earth
pos.earth
Altitude, height on Earth above sea level
pos.earth.altitude
Latitude on Earth
pos.earth.lat
Longitude on Earth
pos.earth.lon
Ecliptic coordinates
pos.ecliptic
Ecliptic latitude
pos.ecliptic.lat
Ecliptic longitude
pos.ecliptic.lon
Earth orientation parameters
pos.eop
Earth nutation
pos.eop.nutation
Ephemeris
pos.ephem
Equatorial coordinates
pos.eq
Declination in equatorial coordinates
pos.eq.dec
Hour-angle
pos.eq.ha
Right ascension in equatorial coordinates
pos.eq.ra
South polar distance in equatorial coordinates
pos.eq.spd
Positional error ellipse
pos.errorEllipse
Reference frame used for positions
pos.frame
Galactic coordinates
pos.galactic
Latitude in galactic coordinates
pos.galactic.lat
Longitude in galactic coordinates
pos.galactic.lon
Galactocentric coordinate system
pos.galactocentric
Geocentric coordinate system
pos.geocentric
Hierarchical Equal Area IsoLatitude Pixelization
pos.healpix
Heliocentric position coordinate (solar system bodies)
pos.heliocentric
Hierarchical Triangular Mesh
Lambert projection
pos.lambert
Local Group reference frame
pos.lg
Local Standard of Rest reference frame
pos.lsr
Lunar coordinates
pos.lunar
Occultation by lunar limb
pos.lunar.occult
Parallax
pos.parallax
Dynamical parallax
pos.parallax.dyn
Photometric parallaxes
pos.parallax.phot
Spectroscopic parallax
pos.parallax.spect
Trigonometric parallax
pos.parallax.trig
Phase angle, e.g. elongation of earth from sun as seen from a third cel. object
pos.phaseAng
Proper motion
pos.pm
Position angle of a given vector
pos.posAng
Precession (in equatorial coordinates)
pos.precess
Supergalactic coordinates
pos.supergalactic
Latitude in supergalactic coordinates
pos.supergalactic.lat
Longitude in supergalactic coordinates
pos.supergalactic.lon
WCS keywords
pos.wcs
WCS CDMATRIX
pos.wcs.cdmatrix
WCS CRPIX
pos.wcs.crpix
WCS CRVAL
pos.wcs.crval
WCS CTYPE
pos.wcs.ctype
WCS NAXES
pos.wcs.naxes
WCS NAXIS
pos.wcs.naxis
WCS scale or scale of an image
pos.wcs.scale
Spectroscopy
spect
Spectral bin size
spect.binSize
Continuum spectrum
spect.continuum
Doppler parameter b
spect.dopplerParam
Radial velocity, derived from the shift of some spectral feature
spect.dopplerVeloc
Radial velocity derived from a wavelength shift using the optical convention
spect.dopplerVeloc.opt
Radial velocity derived from a frequency shift using the radio convention
spect.dopplerVeloc.radio
Spectral index
spect.index
Spectral line
spect.line
Line asymmetry
spect.line.asymmetry
Spectral line broadening
spect.line.broad
Stark line broadening coefficient
spect.line.broad.Stark
Zeeman broadening
spect.line.broad.Zeeman
Line equivalent width
spect.line.eqWidth
Line intensity
spect.line.intensity
Line profile
spect.line.profile
Spectral line strength S
spect.line.strength
Spectral line fwhm
spect.line.width
Spectral (or velocity) resolution
spect.resolution
Observed source viewed on the sky
src
Calibration source
src.calib
Guide star
src.calib.guideStar
Source classification (star, galaxy, cluster...)
src.class
Color classification
src.class.color
Distance class e.g. Abell
src.class.distance
Luminosity class
src.class.luminosity
Richness class e.g. Abell
src.class.richness
Star/galaxy discriminator, stellarity index
src.class.starGalaxy
Structure classification e.g. Bautz-Morgan
src.class.struct
Density of sources
src.density
Source ellipticity
src.ellipticity
Impact parameter
src.impactParam
Morphology structure
src.morph
Morphological parameter
src.morph.param
Scale length for a galactic component (disc or bulge)
src.morph.scLength
Hubble morphological type (galaxies)
src.morph.type
Qualifier indicating that a quantity (e.g. flux) is background subtracted rather than total
src.net
Orbital parameters
src.orbital
Orbit eccentricity
src.orbital.eccentricity
Orbit inclination
src.orbital.inclination
Orbit mean anomaly
src.orbital.meanAnomaly
Mean motion
src.orbital.meanMotion
Ascending node
src.orbital.node
Periastron
src.orbital.periastron
Redshift
src.redshift
Photometric redshift
src.redshift.phot
Sample
src.sample
Spectral type MK
src.spType
Variability of source
src.var
Amplitude of variation
src.var.amplitude
Variability index
src.var.index
Pulse
src.var.pulse
Statistical parameters
stat
Correlation between two parameters
stat.correlation
Covariance between two parameters
stat.covariance
Statistical error
stat.error
Systematic error
stat.error.sys
Filling factor (volume, time, ..)
stat.filling
Fit
stat.fit
Chi-square distribution, test
stat.fit.chi2
Degrees of freedom
stat.fit.dof
Goodness or significance of fit
stat.fit.goodness
Observed minus computed
stat.fit.omc
Parameter of fit
stat.fit.param
Residual fit
stat.fit.residual
Fourier coefficient
stat.Fourier
Amplitude Fourier coefficient
stat.Fourier.amplitude
Likelihood
stat.likelihood
Maximum or upper limit
stat.max
Mean, average value
stat.mean
Median value
stat.median
Minimum or lowest limit
stat.min
Parameter
stat.param
Probability
stat.probability
Signal to noise ratio
stat.snr
Standard deviation
stat.stdev
Qualifier of a generic incalibrated quantity
stat.uncalib
Miscellaneous value
stat.value
Variance
stat.variance
stat.weight
Time, generic quantity in units of time or date
time
Age
time.age
Creation time/date (of dataset, file, catalogue,...)
time.creation
Crossing time
time.crossing
Interval of time describing the duration of a generic event or phenomenon
time.duration
End time/date of a generic event
time.end
Instant of time related to a generic event (epoch, date, Julian date, time stamp/tag,...)
time.epoch
Equinox
time.equinox
Time interval, time-bin, time elapsed between two events, not the duration of an event
time.interval
Lifetime
time.lifetime
Period, interval of time between the recurrence of phases in a periodic phenomenon
time.period
Phase, position within a period
time.phase
A time/date associated with the processing of data
time.processing
Publication year
time.publiYear
Relaxation time
time.relax
The time/date data is available to the public
time.release
Time resolution
time.resolution
Timescale
time.scale
Start time/date of generic event
time.start