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 P: means that the word can only be used as primary or first word Rate (per time unit) arith.rate P: means that the word can only be used as primary or first word Ratio between two quantities described by the same UCD arith.ratio S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Zero point arith.zp Q: means that the word can be used indifferently as first or secondary word Electromagnetic spectrum em S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Channel / instrumental spectral bin coordinate (bin number) em.bin Q: means that the word can be used indifferently as first or secondary word Energy value in the em frame em.energy Q: means that the word can be used indifferently as first or secondary word Frequency value in the em frame em.freq Q: means that the word can be used indifferently as first or secondary word Gamma rays part of the spectrum em.gamma S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Hard gamma ray (>500 keV) em.gamma.hard S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Soft gamma ray (120 - 500 keV) em.gamma.soft S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Infrared part of the spectrum em.IR S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Infrared between 15 and 30 micron em.IR.15-30um S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Infrared between 30 and 60 micron em.IR.30-60um S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Infrared between 3 and 4 micron em.IR.3-4um S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Infrared between 4 and 8 micron em.IR.4-8um S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Infrared between 60 and 100 micron em.IR.60-100um S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Infrared between 8 and 15 micron em.IR.8-15um S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Far-Infrared, 30-100 microns em.IR.FIR S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Infrared between 1.5 and 2 micron em.IR.H S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Infrared between 1.0 and 1.5 micron em.IR.J S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Infrared between 2 and 3 micron em.IR.K S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Medium-Infrared, 5-30 microns em.IR.MIR S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Near-Infrared, 1-5 microns em.IR.NIR S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Designation of major atomic lines em.line S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Bracket gamma line em.line.Brgamma S: stands for only secondary: the word cannot be used as the first word to describe a single quantity CO radio line, e.g. 12CO(1-0) rest wl 115GHz em.line.CO S: stands for only secondary: the word cannot be used as the first word to describe a single quantity H-alpha line em.line.Halpha S: stands for only secondary: the word cannot be used as the first word to describe a single quantity H-beta line em.line.Hbeta S: stands for only secondary: the word cannot be used as the first word to describe a single quantity H-delta line em.line.Hdelta S: stands for only secondary: the word cannot be used as the first word to describe a single quantity H-gamma line em.line.Hgamma S: stands for only secondary: the word cannot be used as the first word to describe a single quantity 21cm hydrogen line em.line.HI S: stands for only secondary: the word cannot be used as the first word to describe a single quantity H-Lyalpha line em.line.Lyalpha S: stands for only secondary: the word cannot be used as the first word to describe a single quantity [OIII] line whose rest wl is 500.7 nm em.line.OIII S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Millimetric/submillimetric part of the spectrum em.mm S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Millimetric between 100 and 200 GHz em.mm.100-200GHz S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Millimetric between 1500 and 3000 GHz em.mm.1500-3000GHz S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Millimetric between 200 and 400 GHz em.mm.200-400GHz S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Millimetric between 30 and 50 GHz em.mm.30-50GHz S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Millimetric between 400 and 750 GHz em.mm.400-750GHz S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Millimetric between 50 and 100 GHz em.mm.50-100GHz S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Millimetric between 750 and 1500 GHz em.mm.750-1500GHz S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Optical part of the spectrum em.opt S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Optical band between 400 and 500 nm em.opt.B S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Optical band between 750 and 1000 nm em.opt.I S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Optical band between 600 and 750 nm em.opt.R S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Optical band between 300 and 400 nm em.opt.U S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Optical band between 500 and 600 nm em.opt.V S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Radio part of the spectrum em.radio S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Radio between 100 and 200 MHz em.radio.100-200MHz S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Radio between 12 and 30 GHz em.radio.12-30GHz S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Radio between 1500 and 3000 MHz em.radio.1500-3000MHz S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Radio between 200 and 400 MHz em.radio.200-400MHz S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Radio between 20 and 100 MHz em.radio.20-100MHz S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Radio between 3 and 6 GHz em.radio.3-6GHz S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Radio between 400 and 750 MHz em.radio.400-750MHz S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Radio between 6 and 12 GHz em.radio.6-12GHz S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Radio between 750 and 1500 MHz em.radio.750-1500MHz S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Ultraviolet part of the spectrum em.UV S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Ultraviolet between 100 and 200 nm em.UV.100-200nm S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Ultraviolet between 10 and 50 nm em.UV.10-50nm S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Ultraviolet between 200 and 300 nm em.UV.200-300nm S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Ultraviolet between 50 and 100 nm em.UV.50-100nm S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Far-Ultraviolet em.UV.FUV S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Wavenumber value in the em frame em.wavenumber Q: means that the word can be used indifferently as first or secondary word Wavelength value in the em frame em.wl Q: means that the word can be used indifferently as first or secondary word Central wavelength em.wl.central Q: means that the word can be used indifferently as first or secondary word Effective wavelength em.wl.effective Q: means that the word can be used indifferently as first or secondary word X-ray part of the spectrum em.X-ray S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Hard X-ray (12 - 120 keV) em.X-ray.hard S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Medium X-ray (2 - 12 keV) em.X-ray.medium S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Soft X-ray (0.12 - 2 keV) em.X-ray.soft S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Instrument instr Q: means that the word can be used indifferently as first or secondary word 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 Q: means that the word can be used indifferently as first or secondary word Bandwidth of the instrument instr.bandwidth Q: means that the word can be used indifferently as first or secondary word Baseline for interferometry instr.baseline Q: means that the word can be used indifferently as first or secondary word Beam instr.beam S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Calibration parameter instr.calib Q: means that the word can be used indifferently as first or secondary word Detector instr.det S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Instrument noise instr.det.noise Q: means that the word can be used indifferently as first or secondary word Point Spread Function instr.det.psf Q: means that the word can be used indifferently as first or secondary word Quantum efficiency instr.det.qe Q: means that the word can be used indifferently as first or secondary word Dispersion of a spectrograph instr.dispersion Q: means that the word can be used indifferently as first or secondary word Filter instr.filter S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Field of view instr.fov S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Observatory, satellite, mission instr.obsty S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Seeing instr.obsty.seeing Q: means that the word can be used indifferently as first or secondary word Offset angle respect to main direction of observation instr.offset Q: means that the word can be used indifferently as first or secondary word Spectral order in a spectrograph instr.order Q: means that the word can be used indifferently as first or secondary word Various instrumental parameters instr.param Q: means that the word can be used indifferently as first or secondary word Pixel (default size: angular) instr.pixel S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Photographic plate instr.plate S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Plate emulsion instr.plate.emulsion Q: means that the word can be used indifferently as first or secondary word Instrument precision instr.precision Q: means that the word can be used indifferently as first or secondary word Instrument saturation threshold instr.saturation Q: means that the word can be used indifferently as first or secondary word Instrument scale (for CCD, plate, image) instr.scale Q: means that the word can be used indifferently as first or secondary word Instrument sensitivity, detection threshold instr.sensitivity Q: means that the word can be used indifferently as first or secondary word Instrument configuration or setup instr.setup Q: means that the word can be used indifferently as first or secondary word Sky level instr.skyLevel Q: means that the word can be used indifferently as first or secondary word Sky temperature instr.skyTemp Q: means that the word can be used indifferently as first or secondary word Telescope instr.tel Q: means that the word can be used indifferently as first or secondary word Telescope focal length instr.tel.focalLength Q: means that the word can be used indifferently as first or secondary word Metadata meta P: means that the word can only be used as primary or first word Abstract (of paper, proposal,etc.) meta.abstract P: means that the word can only be used as primary or first word Bibliographic reference meta.bib P: means that the word can only be used as primary or first word Author name meta.bib.author P: means that the word can only be used as primary or first word Bibcode meta.bib.bibcode P: means that the word can only be used as primary or first word Figure in a paper meta.bib.fig P: means that the word can only be used as primary or first word Journal name meta.bib.journal P: means that the word can only be used as primary or first word Page number meta.bib.page P: means that the word can only be used as primary or first word Volume number meta.bib.volume P: means that the word can only be used as primary or first word Code or flag meta.code P: means that the word can only be used as primary or first word Classification code meta.code.class P: means that the word can only be used as primary or first word limit uncertainty error flag meta.code.error P: means that the word can only be used as primary or first word Membership code meta.code.member P: means that the word can only be used as primary or first word MIME type meta.code.mime P: means that the word can only be used as primary or first word Multiplicity or binarity flag meta.code.multip P: means that the word can only be used as primary or first word Quality, precision, reliability flag or code meta.code.qual P: means that the word can only be used as primary or first word Status code (e.g.: status of a proposal/observation) meta.code.status P: means that the word can only be used as primary or first word Unknown or impossible to understand quantity meta.cryptic P: means that the word can only be used as primary or first word Identity of man/organization responsible for the data meta.curation P: means that the word can only be used as primary or first word Dataset meta.dataset Q: means that the word can be used indifferently as first or secondary word Curation/contact e-mail meta.email Q: means that the word can be used indifferently as first or secondary word File meta.file S: stands for only secondary: the word cannot be used as the first word to describe a single quantity FITS standard meta.fits S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Identifier, name or designation meta.id P: means that the word can only be used as primary or first word Identifier of associated counterpart meta.id.assoc P: means that the word can only be used as primary or first word Name of Co-Investigator meta.id.CoI P: means that the word can only be used as primary or first word Cross identification meta.id.cross P: means that the word can only be used as primary or first word Identification of parent source meta.id.parent P: means that the word can only be used as primary or first word Part of identifier, suffix or sub-component meta.id.part P: means that the word can only be used as primary or first word Name of Principal Investigator meta.id.PI P: means that the word can only be used as primary or first word Main value of something meta.main S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Quantity was produced by a model meta.modelled S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Note or remark (longer than a code or flag) meta.note P: means that the word can only be used as primary or first word Number (of things; e.g. nb of object in an image) meta.number P: means that the word can only be used as primary or first word Record number meta.record P: means that the word can only be used as primary or first word Reference, or origin meta.ref P: means that the word can only be used as primary or first word IVORN, Int. VO Resource Name (ivo://) meta.ref.ivorn Q: means that the word can be used indifferently as first or secondary word URI, universal resource identifier meta.ref.uri Q: means that the word can be used indifferently as first or secondary word URL, web address meta.ref.url P: means that the word can only be used as primary or first word Software used in generating data meta.software S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Table or catalogue meta.table S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Title or explanation meta.title P: means that the word can only be used as primary or first word UCD meta.ucd Q: means that the word can be used indifferently as first or secondary word Unit meta.unit P: means that the word can only be used as primary or first word Version meta.version P: means that the word can only be used as primary or first word Observation obs S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Airmass obs.airMass Q: means that the word can be used indifferently as first or secondary word Atmosphere, atmospheric phenomena affecting an observation obs.atmos S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Atmospheric extinction obs.atmos.extinction Q: means that the word can be used indifferently as first or secondary word Atmospheric refraction angle obs.atmos.refractAngle Q: means that the word can be used indifferently as first or secondary word Calibration observation obs.calib S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Related to flat-field calibration observation (dome, sky, ..) obs.calib.flat S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Exposure obs.exposure S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Region covered by the observation obs.field S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Image obs.image S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Observer, discoverer obs.observer Q: means that the word can be used indifferently as first or secondary word Various observation or reduction parameter obs.param Q: means that the word can be used indifferently as first or secondary word Observation proposal obs.proposal S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Proposal cycle obs.proposal.cycle Q: means that the word can be used indifferently as first or secondary word Sequence of observations, exposures or events obs.sequence S: stands for only secondary: the word cannot be used as the first word to describe a single quantity Photometry phot E: means a photometric quantity, and can be followed by a word describing a part of the electromagnetic spectrum Antenna temperature phot.antennaTemp E: means a photometric quantity, and can be followed by a word describing a part of the electromagnetic spectrum Photometric calibration phot.calib Q: means that the word can be used indifferently as first or secondary word 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 Q: means that the word can be used indifferently as first or secondary word Dereddened color phot.color.reddFree Q: means that the word can be used indifferently as first or secondary word Flux expressed in counts phot.count E: means a photometric quantity, and can be followed by a word describing a part of the electromagnetic spectrum fluence phot.fluence E: means a photometric quantity, and can be followed by a word describing a part of the electromagnetic spectrum Photon flux phot.flux E: means a photometric quantity, and can be followed by a word describing a part of the electromagnetic spectrum Bolometric flux phot.flux.bol Q: means that the word can be used indifferently as first or secondary word Flux density (per wl/freq/energy interval) phot.flux.density E: means a photometric quantity, and can be followed by a word describing a part of the electromagnetic spectrum Flux density surface brightness phot.flux.density.sb E: means a photometric quantity, and can be followed by a word describing a part of the electromagnetic spectrum Flux surface brightness phot.flux.sb E: means a photometric quantity, and can be followed by a word describing a part of the electromagnetic spectrum Limb-darkening coefficients phot.limbDark E: means a photometric quantity, and can be followed by a word describing a part of the electromagnetic spectrum Photometric magnitude phot.mag E: means a photometric quantity, and can be followed by a word describing a part of the electromagnetic spectrum Bolometric correction