 |
International Virtual Observatory Alliance |
| Andrea Preite Martinez (andrea@rm.iasf.cnr.it) |
| Sébastien Derriere (derriere@astro.u-strasbg.fr)
|
This document describes the list of controlled terms used to build the Unified Content Descriptors, Version 1+ (UCD1+).
The document describing the current proposal for a new set of UCD called UCD1+ can be found at the url: http://www.ivoa.net/Documents/UCD/WD-UCD-20040426.html. Here we briefly recall the structure of the proposed UCD1+ and the origin of the present lists.
This is an IVOA Working Draft for review by IVOA members and other interested parties. It is a draft document and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use IVOA Working Drafts as reference materials or to cite them as other than ``work in progress''. A list of current IVOA Recommendations and other technical documents can be found at http://www.ivoa.net/Documents/.
Acknowledgments
This document is based on the W3C documentation standards, but has been
adapted for the IVOA.
1 Definition of atoms and words
A UCD is a string which contains textual tokens called ``words'', separated by semicolons(;). A word is composed of ``atoms'', separated by periods(.). So the hierarchy is the following:
UCD1+ are either single words, or composed words.
UCDs should be "controlled" (through a process that is also indicated in the WD referenced above). Control should be exercised at the level of words (ucd1+) but also at the level of the vocabulary (atoms) used to form words. A consistent list of atoms should be mantained, making sure that the same atom means always the same thing, even if used in combination with different other atoms.
1.1 Definition of atoms
Atoms were defined following these guidelines:
1. abbreviations are kept to a minimum, and only if the result is not ambiguous (ra, dec are OK, but t is ambiguous: we use time and temperature instead).
2. atoms are not hyphenated. The separation is marked by a capital letter to help readability (position angle = posAng) unless the composed word has a well known acronym (signal to noise ratio = snr) or short form (standard deviation = stdev)
1.2 Definition of words
The list of UCD1+ words presented in this document was generated applying
the rules and recommendations of WD-UCD-20040426 to VizieR.
The original motivation was to transform UCD1 into an improved version,
trying to build a list of combinations of new words that could describe
all the existing UCD1 terms.
The procedure that was used was the following:
If the consistency test at Steps 3 was positive, a new UCD1+ was defined, and assigned to all columns described by old UCD1. If detailed additional information was necessary (Step 4), new UCD1+ were assigned to each column and then the results were grouped into "n" new UCD1+s. Eventually, all the columns in VizieR had a new UCD1+ assigned to them. This is slightly different from saying: ``this column in this catalog is assigned this UCD1+'' because the result of a UCD1+ assignation procedure applied to all columns could lead in some cases to more precise UCD1+ or to new ones.
2 The structure of the UCD1+ tree
All existing UCD1+ words are grouped into 12 main categories. These categories are expressed by the first atom of the word, whose possible values are:
We include in this section concepts involving or indicating some mathematical operation performed on the primary ``concept'' or just the presence of an arithmetic factor or operator.
This section describes the electromagnetic spectrum, either in a monochromatic way or in predefined intervals. The complete list of proposed bands (in seven classical regions of the e.m. spectrum: radio, millimeter, infrared, optical, ultraviolet, x-ray and gamma-ray), can be found in the document Note-EMSpectrum-20040520
In this section we gather all the quantities related to astronomical instrumentation, e.g. detectors (plates, CCDs, etc.), spectrographs, telescopes (but also observatories or missions), etc.
This section includes all the information that is not coming directly from a measure, and info that could not be included in other sections.
In principle under this section should go all words describing an observation (the name of the observer or PI, the observing conditions, the name of the field). In practice, the section is very ``thin'' and could be deleted, if the sparse content could be housed elsewere.
All the words describing photometric measures are included in this section. Basically we distinguish between a flux density (flux per unit frequency interval), a flux density integrated over a given e.m. interval (flux if expressed linearly, mag if expressed by a log), or a flux expressed in counts/s (if the setup of the detector is photon counting observing mode). We also include ``colors'', which are differences of magnitudes (i.e. ratios of fluxes) measured in different e.m. bands. In the present proposal we tried to simplify the PHOT section of old UCD1, keeping only the most important (used, diffuse) colors.
Atomic and molecular data (mainly used for spectroscopy) and basic physical quantities (temperature, mass, gravity, luminosity, etc.)
All quantities related to the position of an object, in general on the sky. Angular quantities, with the exception of projections from spherical to rectangular systems. Also angular measurements in general (the angular size of an object is in this section, its linear size is in the phys section). The WCS FITS keywords are placed here for the moment.
For historical reasons, photometric data taken in narrow spectral bands with instruments called spectrographs are classified as spectroscopic data. Don't miss up with ``em''. Bi-dimensionally speaking, em represents the x axis, phot and spect the y axis.
This is a rather generic section, mainly devoted to source classifications. For no other than practical reasons, variability, orbital and velocity data are also included in this section.
Statistical information on measurements.
Quantities related to time (age, date, period, etc.)
All words are preceded by a ``syntax'' code that can help in the process of building composed UCD1+. The code "P" means that the word can only be used as "primary" or first word, "S" stands for only secondary, code "Q" means that the word can be used indifferently as first or secondary word.
S arith.diff difference amplitude deviation offset correction
P arith.factor factor exponent power-of correction scaling dilution
P arith.grad gradient
P arith.rate rate change
S arith.ratio ratio relative normalized fraction decrement
S arith.zp zero point scaling offset constant coefficient
S em.IR infrared IR
S em.IR.15-30um infrared 15-30 um
S em.IR.3-4um infrared 3-4 um
S em.IR.30-60um infrared 30-60 um
S em.IR.4-8um infrared 4-8 um
S em.IR.60-100um infrared 60-100 um
S em.IR.8-15um infrared 8-15 um
S em.IR.H H infrared
S em.IR.J J infrared
S em.IR.K K infrared
S em.IR.K.Brgamma Bracket gamma line
S em.UV ultraviolet UV
S em.UV.10-50nm UV 10-50 nm
S em.UV.100-200nm UV 100-200 nm
S em.UV.200-300nm UV 200-300 nm
S em.UV.50-100nm UV 50-100 nm
S em.X-ray X-ray
S em.X-ray.hard hard X-ray
S em.X-ray.medium medium X-ray
S em.X-ray.soft soft X-ray
Q em.energy energy wave
Q em.freq frequency wave
S em.gamma.hard hard gamma ray
S em.gamma.soft soft gamma ray
S em.mm.100-200GHz millimeter 100-200 GHz
S em.mm.1500-3000GHz millimeter 1500-3000 GHz
S em.mm.200-400GHz millimeter 200-400 GHz
S em.mm.30-50GHz millimeter 30-50 GHz
S em.mm.400-750GHz millimeter 400-750 GHz
S em.mm.50-100GHz millimeter 50-100 GHz
S em.mm.750-1500GHz millimeter 750-1500 GHz
S em.opt optical
S em.opt.B B optical 400-500nm
S em.opt.B.Hbeta H-beta
S em.opt.I I optical 750-1000um
S em.opt.R R optical 600-7500um
S em.opt.R.Halpha H-alpha
S em.opt.U U optical 300-400um Balmer jump
S em.opt.V V optical 500-600nm
S em.opt.V.OIII [OIII]
S em.radio radio
S em.radio.100-200MHz radio 100-200 MHz
S em.radio.12-30GHz radio 12-30 GHz
S em.radio.1500-3000MHz radio 1500-3000 GHz
S em.radio.20-100MHz radio 20-100 MHz
S em.radio.200-400MHz radio 200-400 MHz
S em.radio.3-6GHz radio 3-6 GHz
S em.radio.400-750MHz radio 400-750 MHz
S em.radio.6-12GHz radio 6-12 GHz
S em.radio.750-1500MHz radio 750-1500 MHz 21cm
Q em.wl wavelength wave
Q em.wl.central central median wavelength
Q em.wl.effective effective wavelength
S instr instrument
Q instr.ang-res angular resolution
Q instr.antenna-temp antenna temperature
Q instr.area collecting area of detector
Q instr.background background of instrument
Q instr.bandpass bandpass passband of instrument
Q instr.bandwidth bandwidth fwhm width range instrument filter
Q instr.baseline baseline interferometry
Q instr.beam-width beam width size
Q instr.calib calibration
Q instr.det detector
Q instr.det.noise noise of detector instrument
Q instr.det.psf psf point spread function
Q instr.det.qe quantum efficiency
Q instr.filter filter
Q instr.filter.transm transmission response
Q instr.fov field of view angular aperture
S instr.obsty observatory satellite mission
Q instr.obsty.site telescope location (site, altitude)
Q instr.obsty.site.seeing seeing
Q instr.offset off-axis drift offset angle
Q instr.param instrument parameter
Q instr.pixel pixel
Q instr.plate plate photographic
Q instr.plate.emulsion plate emulsion
Q instr.precision precision instrument
Q instr.saturation saturation threshold detection
Q instr.scale scale instrument
Q instr.sensitivity sensitivity threshold detection
Q instr.setup configuration setup instrument
Q instr.sky-level sky level
Q instr.sky-temp sky temperature
Q instr.spect spectrograph
Q instr.spect.dispersion dispersion scale spectrograph
Q instr.spect.order spectral order
Q instr.spect.resolution spectral resolution resolving power velocity
S instr.tel telescope
Q instr.tel.focus focus focal length telescope
P meta.bib bibliographic reference publication article paper
P meta.bib.author author name
P meta.bib.bibcode bibcode bibliographic code
P meta.bib.fig figure
P meta.bib.journal journal name
P meta.bib.page page number
P meta.bib.volume volume number
P meta.code code flag type
P meta.code.class classification
P meta.code.member membership
P meta.code.mime MIME type
P meta.code.multip multiplicity binarity
P meta.code.qual quality code
P meta.cryptic unknown or impossible to understand
S meta.dataset dataset
Q meta.file file
S meta.fits fits
Q meta.fits.software software used in generating FITS file
P meta.id identifier name designation number
P meta.id.assoc associated counterpart
P meta.id.cross cross identification
P meta.id.parent parent member identification of source
S meta.main main principal
S meta.modelled quantity was produced by a model
P meta.note note remark
P meta.number number (of things)
P meta.record record number running number
P meta.ref reference source origin
Q meta.ref.url URL, web address
Q meta.table table catalogue
Q meta.table.axis axis table
P meta.title title or explanation
P meta.unit units
Q obs observation
Q obs.air.extinction atmospheric extinction
Q obs.air.mass airmass air mass
Q obs.field field zone sky region frame map plate area
Q obs.image image
Q obs.observer PI observer discoverer
Q obs.param parameter observation reduction analysis
Q phot photometry
Q phot.calib calibration photometric
Q phot.color color index magnitude difference
Q phot.color.B-R B-R color
Q phot.color.B-R.JHN B-R Johnson color
Q phot.color.B-V B-V color
Q phot.color.B-V.JHN B-V Johnson color
Q phot.color.B1-B.gen B1-B Geneva color
Q phot.color.B2-B.gen B2-B Geneva color
Q phot.color.G-B.gen G-B Geneva color
Q phot.color.H-K H-K color
Q phot.color.J-H J-H color
Q phot.color.J-K J-K color
Q phot.color.K-L K-L color
Q phot.color.R-I.JHN R-I Johnson color
Q phot.color.U-B U-B color
Q phot.color.U-B.JHN U-B Johnson color
Q phot.color.U-B.gen U-B Geneva color
Q phot.color.U-V.JHN U-V Johnson color
Q phot.color.V-B.gen V-B Geneva color
Q phot.color.V-I.cous V-I Cousins color
Q phot.color.V-R.JHN V-R Johnson color
Q phot.color.V-R.cous V-R Cousins color
Q phot.color.V1-B.gen V1-B Geneva color
Q phot.color.b-y.STR b-y Stroemgren color
Q phot.color.c1.STR c1 Stroemgren color
Q phot.color.excess color excess
Q phot.color.g-r.gunn g-r Gunn color
Q phot.color.m1.STR m1 Stroemgren
Q phot.color.opt-ir optical infrared color
Q phot.color.opt-uv optical UV color
Q phot.color.reddFree dereddened reddening-free color
Q phot.count flux expressed in counts(/s)
Q phot.fluence fluence
Q phot.flux flux
Q phot.flux.bol bolometric flux
Q phot.fluxDens density monochromatic flux continuum Jy, W/m2 per wl/freq/energy interval
Q phot.fluxDens.sb flux density surface brightness
Q phot.limbDark limb-darkening
Q phot.mag magnitude
Q phot.mag.bc bolometric correction
Q phot.mag.bol bolometric magnitude
Q phot.mag.distMod distance modulus
Q phot.mag.reddFree reddening-free dereddened
Q phot.mag.sb surface brightness magnitude
Q phot.sb surface brightness
Q phys.SFR SFR star formation rate
Q phys.absorption extinction absorption
Q phys.absorption.coeff absorption extinction opacity coefficient
Q phys.absorption.gal galactic extinction absorption
Q phys.absorption.gf gaunt factors
Q phys.absorption.opticalDepth optical depth tau
Q phys.abund abundance
Q phys.abund.Fe metallicity Fe/H abundance
Q phys.abund.X hydrogen abundance
Q phys.abund.Y helium abundance
Q phys.abund.Z metallicity abundance
Q phys.acceleration acceleration
Q phys.albedo albedo reflectance
Q phys.angMomentum angular momentum
Q phys.at atomic
Q phys.at.coll collisional atomic
Q phys.at.coll.rate collisional emissivity excitation rate
Q phys.at.coll.strength collisional strength
Q phys.at.crossSect atomic cross-section
Q phys.at.damping damping van der Waals
Q phys.at.element atomic element
Q phys.at.energy atomic energy
Q phys.at.energy.ioniz ionization energy potential
Q phys.at.energy.level energy level excitation transition potential energy
Q phys.at.fs fine structure
Q phys.at.ion ionization stage
Q phys.at.level level electronic configuration identification designation
Q phys.at.level.lifetime radiative lifetime
Q phys.at.level.parity parity
Q phys.at.level.sweight statistical weight
Q phys.at.line atomic line
Q phys.at.line.emissivity atomic line emissivity
Q phys.at.line.strength atomic line strength
Q phys.at.number atomic number Z
Q phys.at.osc-strength oscillator strength gf f
Q phys.at.qn quantum number atomic structure
Q phys.at.recombin recombination
Q phys.at.stark stark broadening intensity
Q phys.at.trans atomic transition
Q phys.at.trans.energy transition energy wavenumber
Q phys.at.trans.prob atomic transition probability
Q phys.at.trans.rate rate of transition
Q phys.at.trans.wl wavelength of transition
Q phys.at.weight atomic weight
Q phys.columnDensity column density
Q phys.density density mass number electron energy surface
Q phys.dielectric dielectric
Q phys.dispMeas dispersion measure
Q phys.distance distance
Q phys.distance.compon component distance
Q phys.distance.gc galactocentric distance
Q phys.electField electric field
Q phys.electron.degen degeneracy electron eta
Q phys.electron.energy energy electron
Q phys.emissMeasure emission measure
Q phys.emissivity emissivity
Q phys.energy energy thermal integrated component loss
Q phys.eos equation of state EOS
Q phys.excitParam excitation parameter U
Q phys.extension extension size area angular width diameter
Q phys.gravity gravity surface
Q phys.ionizParam.coll collisional ionization
Q phys.ionizParam.rad radiative ionization
Q phys.luminosity luminosity
Q phys.luminosity.fun luminosity function
Q phys.magAbs absolute magnitude
Q phys.magAbs.bol bolometric absolute magnitude
Q phys.magField magnetic field
Q phys.mass mass
Q phys.mass.fraction mass fraction
Q phys.mass.light mass to light ratio
Q phys.mass.loss mass loss outflow transfer rate flux
Q phys.massYield mass yield
Q phys.mol molecular data
Q phys.mol.dipole dipole molecular electric
Q phys.mol.energy energy molecular state dissociation
Q phys.mol.energy.rotat rotational energy molecular
Q phys.mol.formation.heat heat formation
Q phys.mol.level level molecular
Q phys.mol.line.strength line strength molecular
Q phys.mol.qn quantum number molecular structure
Q phys.mol.trans transition molecular
Q phys.polarization polarization
Q phys.polarization.posAng orientation angle polarization
Q phys.polarization.rotMeas rotation polarization
Q phys.polarization.stokes stokes polarization
Q phys.pressure pressure
Q phys.refraction refraction
Q phys.size size length height dimension aperture diameter
Q phys.size.area area of an object
Q phys.size.diameter diameter
Q phys.size.radius radius
Q phys.temperature temperature
Q phys.temperature.effective effective temperature
Q phys.temperature.electron electron temperature
Q pos position
Q pos.ang angular distance
Q pos.ang.separation separation distance offset angular
Q pos.az alt-azimutal
Q pos.az.alt altitude elevation alt-azimutal
Q pos.az.ha hour-angle elongation azimuth
Q pos.az.zd zenith distance
Q pos.barycenter barycenter
Q pos.det position on instrument detector CCD pixel
Q pos.dirCos direction cosine vector
Q pos.earth.lat latitude on Earth
Q pos.earth.lon longitude on Earth
Q pos.earth.nutation Earth nutation
Q pos.ec.lat ecliptic latitude
Q pos.ec.lon ecliptic longitude
Q pos.ee ellipse positional error
Q pos.ephem ephemeris
Q pos.eq equatorial coordinates
Q pos.eq.dec declination dec equatorial
Q pos.eq.dec.arcsec arcsec declination
Q pos.eq.ra right ascension ra equatorial
Q pos.eq.ra.minutes minutes right ascension
Q pos.eq.ra.seconds seconds right ascension
Q pos.frame Reference frame used for positions
Q pos.gal galactic coordinates
Q pos.gal.compon component galactic coordinates cartesian
Q pos.gal.lat latitude in galactic coordinates
Q pos.gal.lon longitude in galactic coordinates
Q pos.lunar.occult occultation lunar limb
Q pos.parallax parallax
Q pos.parallax.dyn dynamical parallaxes
Q pos.parallax.phot photometric parallaxes
Q pos.parallax.spect spectroscopic parallaxes
Q pos.parallax.trig trigonometric parallaxes
Q pos.pm proper motion
Q pos.pm.dec proper motion in declination pmdec
Q pos.pm.ra proper motion in right ascension pmra
Q pos.posAng position angle vector
Q pos.precess precession
Q pos.precess.dec precession in declination
Q pos.precess.ra precession in right ascension
Q pos.proj projection coordinates position
Q pos.sg.compon rectangular cartesian supergalactic coordinates
Q pos.sg.lat latitude in supergalactic coordinates
Q pos.sg.lon longitude in supergalactic coordinates
P pos.wcs.cdmatrix WCS CDMATRIX
P pos.wcs.crpix WCS CRPIX
P pos.wcs.crval WCS CRVAL
P pos.wcs.ctype WCS CTYPE
P pos.wcs.naxes WCS NAXES
P pos.wcs.naxis WCS NAXIS
P pos.wcs.scale WCS scale or scale of an image
Q spect.doppler Doppler parameter b
Q spect.index spectral index
Q spect.index.Halpha H-alpha spectral index
Q spect.index.Hbeta H-beta spectral index
Q spect.index.Hgamma H-gamma spectral index
Q spect.line spectral line
Q spect.line.asymmetry asymmetry line
Q spect.line.broad broadening spectral line
Q spect.line.broad.Zeeman Zeeman broadening
Q spect.line.eqwidth equivalent width line
Q spect.line.intensity intensity line strength temperature
Q spect.line.profile profile line
Q spect.line.veloc radial velocity spectral line
Q spect.line.width width fwhm moment spectral line
S src source
Q src.class classification type code
Q src.class.color color classification source
Q src.class.distance Abell distance class
Q src.class.luminosity luminosity class
Q src.class.richness richness Abell class
Q src.class.star-galaxy star galaxy discriminator classification
Q src.class.struct structure classification bautz-morgan
Q src.density density surface sources counts
Q src.ellipticity ellipticity
Q src.fwhm fwhm angular size full width at half maximum
Q src.impactParam impact parameter
Q src.morph morphology structure
Q src.morph.param morphological parameter code bar spiral arm structure
Q src.morph.scLength scale length for a galactic component (disc or bulge)
Q src.morph.type morphological type Hubble galaxies
Q src.orbital orbital
Q src.orbital.eccentricity eccentricity orbital
Q src.orbital.energy energy orbital
Q src.orbital.inclination inclination angle orbit
Q src.orbital.meanAnomaly mean anomaly orbital
Q src.orbital.node node ascending longitude orbital
Q src.orbital.periastron periastron
Q src.orbital.separation separation orbital components
Q src.orbital.size size orbit major axis
Q src.orbital.veloc velocity orbital
Q src.redshift redshift
Q src.sample sample
Q src.separation separation sources
Q src.spType spectral type MK
Q src.var variability source
Q src.var.amplitude amplitude variation
Q src.var.index index variability
Q src.var.pulse pulse
Q src.veloc velocity radial
Q src.veloc.ang angular velocity, drift motion of a source
Q src.veloc.cmb CMB velocity
Q src.veloc.compon component velocity
Q src.veloc.dispersion dispersion velocity
Q src.veloc.escape escape velocity
Q src.veloc.expansion expansion velocity
Q src.veloc.gc galactocentric radial velocity
Q src.veloc.geoc geocentric radial velocity
Q src.veloc.hc heliocentric radial velocity
Q src.veloc.lg Local Group radial velocity
Q src.veloc.lsr Local Standard Rest radial velocity
Q src.veloc.microTurb micro-turbulence microturbulence velocity
Q src.veloc.pulsat pulsational velocity
Q src.veloc.rotat rotational velocity
Q stat statistical
Q stat.Fourier Fourier coefficient
Q stat.Fourier.amplitude amplitude Fourier coefficient
P stat.covariance Covariance between two parameters
P stat.error error
Q stat.fit fit
Q stat.fit.chi2 chi2 chi reduced
Q stat.fit.dof degrees freedom fit
Q stat.fit.goodness goodness significance probability fit
Q stat.fit.omc difference observed measured minus computed theoretical model
Q stat.fit.param parameter model fit correlation
Q stat.fit.residual residual fit
Q stat.likelihood likelihood
S stat.max maximum upper max limit
S stat.mean mean average
S stat.median median
S stat.min minimum lowest min limit
Q stat.param parameter model
P stat.snr signal to noise ratio
P stat.stdev standard deviation rms sigma
Q stat.value miscellaneous value
P stat.variance variance second order moment
P stat.weight statistical weight
Q time time
Q time.age age evolutionary time
Q time.crossing crossing time Hubble
Q time.epoch epoch julian date time UT
Q time.equinox equinox
Q time.expo exposure time integrated elapsed total corrected cumulative
Q time.expo.end end exposure observation
Q time.expo.start start exposure observation
Q time.interval interval duration time
Q time.period period cycle
Q time.phase phase
Q time.relax relaxation time
Q time.resolution time resolution
Q time.scale scale of time timescale