VO access to Gaia DR1 - WebHome < IVOA < TWikiwiki.ivoa.net/.../InteropOct2016Apps/Apps2-TBoch-VO-access-GaiaDR… · VO access to Gaia DR1: TAP ... 5. IVOA Interop - Trieste 2016

VOaccesstoGaiaDR1:TAP,ConeSearch,COOSYSandHiPS

ThomasBoch,onbehalfoftheCDSteamTriesteInterop,Apps2

IVOA Interop - Trieste 2016 - Apps II

GaiaDR1

• ReleasedSeptember14th2016

• Content

• gaia_source:positionandflux(Gband) for1billionsources

• TGAS:position,flux,propermotionsandparallax for2millionsources

• lightcurvesforRRLyraeandCepheid

• QSOs

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Whodistributesthedata?

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Officialarchive GaiaarchiveatESAC VOTable TAP SAMP

Partnerdatacenters

AIP VOTable SAMP

ARI VOTable TAP CS SAMP

ASDC VOTable

CDS VOTable TAP CS SAMP

Externaldatacenters

IRSA VOTable TAP CS

GAVO VOTable TAP


Whodistributesthedata?

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Officialarchive GaiaarchiveatESAC VOTable TAP SAMP

Partnerdatacenters

AIP VOTable SAMP

ARI VOTable TAP CS SAMP

ASDC VOTable

CDS VOTable TAP CS SAMP

Externaldatacenters

IRSA VOTable TAP CS

GAVO VOTable TAP


GaiaDR1atCDS

• VizieR

• TAPVizieR

• Cross-matchservice

• Aladin

• HiPScatalogue

http://cds.unistra.fr/gaia

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http://cds.unistra.fr/gaia


GaiaDR1atCDS:VizieR

• VizieRwebinterface

• Querybyposition +constraintsonfields

• ConeSearchinterface

• Lightcurvesvisualization

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GaiaDR1atCDS:VizieR





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GaiaDR1atCDS:VizieR





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GaiaDR1atCDS:VizieR





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GaiaDR1atCDS:VizieR





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GaiaDR1atCDS:VizieR





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3+ million querieslast month


GaiaDR1atCDS:VizieRTAP

• GaiaDR1tablesavailableinTAPVizieR

• UserscanqueryGaiatablesandcomplement/jointhemwithanyavailableVizieRtable(notablyHipparcos,Tycho,largesurveyslike2MASS,SDSS,etc)

• Webinterface:http://tapvizier.u-strasbg.fr/adql/

• TAPendpoint:http://tapvizier.u-strasbg.fr/TAPVizieR/tap/

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http://tapvizier.u-strasbg.fr/adql/

http://tapvizier.u-strasbg.fr/TAPVizieR/tap/







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GaiaDR1atCDS:xmatchservice

• Fastpositionalcross-identificationofGaiasourceswithanyVizieRtablewithposition (oruser-uploadedtable)

• Webinterface:http://cdsxmatch.u-strasbg.fr/xmatch

• HTTPAPI

• astroquery

• Topcat

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http://cdsxmatch.u-strasbg.fr/xmatch





• HTTPAPI

• astroquery

• Topcat

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• HTTPAPI

• astroquery

• Topcat

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• HTTPAPI

• astroquery

• Topcat

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Stats: 130M positions submitted from 200+ different IPs



GaiaDR1atCDS:Aladin

• DedicatedformtoaccessGaiadatainAladinDesktop

• Visualizationofpropermotions

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GaiaDR1atCDS:Aladin



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GaiaDR1atCDS:Aladin



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GaiaDR1atCDS:HiPScatalogue

• HiPSprogressivecataloguebuiltfromGaiadatahttp://cds.unistra.fr/Gaia/DR1/AL-visualisation.gml

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http://cds.unistra.fr/Gaia/DR1/AL-visualisation.gml


GaiaDR1atCDS:HiPScatalogue

• HiPSprogressivecataloguebuiltfromGaiadatahttp://cds.unistra.fr/Gaia/DR1/AL-visualisation.gml

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http://cds.unistra.fr/Gaia/DR1/AL-visualisation.gml


VOaccesstoGaiadata:thegood,thebad,theugly

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VOaccesstoGaia:thegood

• Dataavailablethroughnumerousservices

• Servicesdoworkfine

• SamecolumnnamesinallTAPservices

• user-friendly

• allowsforeasyre-launchofthesamequeryondifferentservices

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VOaccesstoGaia:theugly

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• PoormetadatadescribingoutputFIELDs

• noUCD

• nounit

• non-standardnon-parseableunits



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unit="Angle[deg]"

unit="Time[Julian Years]"


• noUCD

• nounit




• Unitparser/validator:http://www.astro.gla.ac.uk/users/norman/ivoa/unity/

• UCDtools:http://cds.unistra.fr/UCD/tools.htx

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unit="Angle[deg]"

unit="Time[Julian Years]"


• noUCD

• nounit


http://www.astro.gla.ac.uk/users/norman/ivoa/unity/

http://cds.unistra.fr/UCD/tools.htx


VOaccesstoGaia:thebad

• (Lackof)definitionofcoordinatesysteminVOTableoutput

• examples

• nodescriptionatall

• inaccuratedescription

• accuratedescription

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Nodescription

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Nodescription

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Nodescription

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Coordinate system?


Nodescription

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Coordinate system?

Epoch?


Inaccuratedescription

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But Gaia positions are in ICRS!


Accuratedescription

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Accuratedescription

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Accuratedescription

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Accuratedescription

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Accuratedescription

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Based on Referencing STC in VOTable note v2.0


Howtoimprovedescriptionofcoordinates?

• InBanff(nov2014):

• only1serviceprovider(outof20tested)wasdescribingcoordinatesaccordingtotheReferencingSTCinVOTablenote

• only1clientwasparsingthedescriptionasexpected

• suggestiontoun-deprecateCOOSYSasatemporarysolutiontoincreasenumberofservicesandclientssupportingcoordinatesdescription/parsing

• COOSYSnotenough,can’tdescribeeverything(eg:differentepochforeachsource)

• Howshallwegoon?

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VO access to Gaia DR1 - WebHome < IVOA < TWikiwiki.ivoa.net/.../InteropOct2016Apps/Apps2-TBoch-VO-access-GaiaDR… · VO access to Gaia DR1: TAP ... 5. IVOA Interop - Trieste 2016

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